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HTML Can âsecond lifeâ EV batteries work as grid-scale energy storage?
sciencesama wrote 7 hours 54 min ago:
Alao you can get a 10kv new battery for less than 2.5 (deye)
declan_roberts wrote 10 hours 1 min ago:
I've spoken to people about starting a Tesla EV battery replacement
business here. Battery replacement on a Tesla is a pretty simple
process that can be done by one person in about 4 hours.
The problem is that it's still really hard to get your hands on salvage
Tesla batteries. Enthusiasts and hackers snatch them up quickly and the
used price is not very competitive with a new EV replacement from
Tesla.
metalman wrote 16 hours 58 min ago:
NO! first
only if industry and government grow some gonads and fully standardise
the cells, and hardware
for battery packs to allow for quick and easy dissasembly, testing,
repair, and reuse, for off grid, and secondary mobile use, as industry
will never trust used components for primary aplications,
it is impossible to overstate how allergic industry is to this.....
second
sodium is comming NOW!, and it is cheaper and safer.
Xemplolo wrote 14 hours 57 min ago:
"NO!" while companies already do this successfully.
But hey, why not being negative first eh? ;P
metalman wrote 3 hours 55 min ago:
successfull?, maybe, we will see if fires, insurance, and end of
life disposal costs leave any roe, plus there are no large scale
used car battery grid storage plants, just green washing for data
centers, where they are most definitly worried about fires, given
the huge spacing between units,
green washing/cred,scamenomics,, but most certainly, not grid
scale
janosch_123 wrote 17 hours 13 min ago:
Https://allye.com are assembling a 1 megawatt hour unit. I got a tour
last week, super exciting.
They raised another $2.5M round too.
Fellten and Allye are the biggest two here in the UK I think.
Havoc wrote 17 hours 24 min ago:
The model makes intuitive sense. Just a question of timing and scale
Gabrys1 wrote 17 hours 40 min ago:
> Can âsecond lifeâ EV batteries work as grid-scale energy storage?
Yes.
Thank you
michidk wrote 18 hours 30 min ago:
see
HTML [1]: https://stabl.com/
pensatoio wrote 1 day ago:
What we really need is standard two way charging on these cars. Every
home with an EV should have a backup battery built into the deal.
casey2 wrote 1 day ago:
Not second life, but first life. All EVs and charging stations should
be reversible. In a world where fossil fuels cost their true value
(~10x as much) and people still drive this would be a necessity for
electricity generation
AtlasBarfed wrote 1 day ago:
I think car cells will be much more useful if they are packaged as
replacement batteries for all the various battery powered tools,
ebikes, etc.
There's a consumer profit margin to absorb the repackaging and
teardown.
Maybe for home grid batteries they'll work too. Again, a consumer
margin.
Sodium Ion and other grid-specific storage will simply be too cheap for
secondhand EV batteries to compete. And the retiring cells won't be any
better in density and will be less safe than the higher density sodium
ion and LFP that is hitting the market.
HocusLocus wrote 1 day ago:
In an ice storm and cold cloudy snap that sweeps the country, NO
lithium batteries will save the grid. I'm weary of this tunnel vision
of the absurd. The only 'storage' that works is to pump water uphill
with 'surplus' energy, and there is not and never will be a surplus.
And these evaporartion tanks are on a scale that ecologists have to
remember countless horror stories (eg., Glenn Canyon Dam). And of
course there's always "mfft!" (another scheme with no numbers behind it
so it's credible because I'm talking about it).
The last time there was anything rational on the table was Perry under
the Trump administration's 30-day rule proposal ( [1] ). It gave a hard
industry incentive to any energy supplier who can have 30 days' fuel on
site. This means nuclear and coal. This was no gimmick, it was the
first time anyone faced reality about National Security as related to
Energy for the grid and survival. And now AI datacenter yadda yadda,
we're also talking about the luxury of keeping schools heated in
Winter. Adverse weather even for a week is grid down game over for
wind and solar. Proven natural gas are ~300 years, joy! As soon as
they get around to sending pregnant whales across the ocean (losing
~20% of the gas-energy in cooling) it may even last 50 years! Before we
have to go to endless war again.
HTML [1]: https://www.nucnet.org/news/nuclear-is-vital-to-us-national-se...
kibitzor wrote 1 day ago:
>So top of the list for us, of course, designing this thing is safety.
Funny issue I learned after talking to a founder at a similar company:
although the battery packs were certified safe for cars (passing crash
tests, wild heat differences from AK to AZ, people sitting on top of
the battery packs in the car)
... the founder had issues re-certifying the batteries for safe use in
a static location for grid storage.
The certification process treated his company like the batteries were
made from scratch even though they used the same BMS/coolant lines/etc.
already proven and tested.
It's clear you still need strong safety regulations and practices in
the rare case there's an event, but the founder noted the grid storage
industry regulations were adding redundant safety testing and slowing
down adoption. The founder also added it's difficult to compete on cost
even with effectively free used EV batteries in this startup space of
grid storage against the low cost of Chinese made grid-specific
batteries due to the added testing + custom hardware + space
constraints and other items. (Caveat: I didn't fact check any of their
statements)
Lucian6 wrote 1 day ago:
Having worked extensively with battery systems, I think the grid
storage potential of second-life EV batteries is more complex than it
appears. We found that typical EV batteries retain 70-80% capacity
after 8-10 years of vehicle use, but the real challenge is
standardization and integration. Different manufacturers use vastly
different battery management systems (BMS) and cell configurations - a
Tesla pack is fundamentally different from a Nissan Leaf pack.
The economics are interesting though. New grid storage batteries cost
around $200-300/kWh, while second-life EV batteries can be acquired for
$50-100/kWh. However, you need to factor in significant integration
costs (~$50-75/kWh) to build compatible BMS systems and thermal
management. We also found cycle life degrades about 20% faster in
repurposed packs compared to new ones, likely due to accumulated stress
patterns from automotive use.
Has anyone here successfully integrated mixed second-life batteries at
scale? I'm particularly curious about how you handled thermal
management across different pack designs while maintaining safe
operating parameters.
jwr wrote 10 hours 44 min ago:
> the real challenge is standardization and integration. Different
manufacturers use vastly different battery management systems (BMS)
and cell configurations - a Tesla pack is fundamentally different
from a Nissan Leaf pack.
Isn't that exactly what the article is about? Have you actually read
the article?
Xemplolo wrote 15 hours 9 min ago:
How can this be a real issue?
We don't have a lot of car makers and we do not have a huge amount of
EV models.
Either you are doing this on small scale, than you can select one or
two specific EV models and use these batterie packs or you do it in
big scale, than you can also easily adapt the most x batterie packs
and only use these across your system.
If you go down to the cell level, its more effort true but then you
probably only handel cell types of a handfull of manufacturer again.
DanielHB wrote 12 hours 43 min ago:
You can't really mix different types of cells together in the same
pack. Even cells with the same manufacturer and chemistry can be
problematic to mix if they are at different wear levels (or even
from different batches from the same factory).
This is only practical if you reuse the whole pack, or at least the
modules. And for that to work well you also need a lot of complex
software to keep the packs working well with each other (like
balancing power levels between the packs).
BMS software is no joke, it is already hard and complex enough when
using brand new battery packs and cells of the same chemistry and
manufacturer and wear level. Any kind of mixing massively increases
the complexity and safety concerns.
Xemplolo wrote 10 hours 45 min ago:
So they already come with a BMS.
Create a MetaBMS. The BMS of the cell pack doesn't care if a car
requests energy between 0 and max and a BMS doesn't care either
if it gets 0-100 kWh.
My car can easily charge from a household plug up to fast
charger. My car consumes very random amounts of energy while i
drive.
overfeed wrote 21 hours 42 min ago:
> Having worked extensively with battery systems, I think the grid
storage potential of second-life EV batteries is more complex than it
appears.
Complex, by t very much doable. Toyota implemented such a system with
enough packs to power a Mazda factory [1] > However, you need to
factor in significant integration costs (~$50-75/kWh) to build
compatible BMS systems and thermal management.
Shouldn't this be a once-off cost per battery-pack version? Or was
this your armortized cost for your deployment capacity. If you've
written the BMS for a 2019 Model 3 Panasonic battey pack once, won't
you reuse it for all the subsequent battery packs of the same
model/SKU?
1.
HTML [1]: https://news.ycombinator.com/item?id=44998010
adwn wrote 19 hours 12 min ago:
> Shouldn't this be a once-off cost per battery-pack version?
A BMS isn't just software. It requires a µC, voltage and
temperature sensors for cell monitoring, and power electronics for
cell balancing. However, those are all comparatively cheap,
especially at scale, and the quoted cost of 50â75 US$/kWh looks
ridiculously overpriced to me.
overfeed wrote 13 min ago:
I expect EV batteries to have all those components preinstalled
already, and naively thought the grid-integration involves
reverse engineering the battery's protocol, and perhaps
bypassing/replacing a µC or 3.
adwn wrote 21 hours 43 min ago:
> New grid storage batteries cost around $200-300/kWh
That doesn't sound right. You can already get high-quality, prismatic
LFP cells for ~50 US$/kWh [1] from European distributors at
low-volumes, so bulk from China should be even cheaper. And there's
no way that balancing and BMS cost an additional 150-250 US$/kWh at
scale, not even a tenth of that.
HTML [1]: https://www.nkon.nl/novat/eve-lf230-prismatic-230ah-230a-lif...
mcbishop wrote 13 hours 15 min ago:
Right, $200-300/kWh is more the range for ~16kWh residential
stationary energy storage systems.
chrisra wrote 1 day ago:
> the real challenge is standardization and integration
In what sense? I'm a newbie, but curious because I'm working on stuff
related to [1] .
HTML [1]: https://mesastandards.org/mesa-der-std/
tedk-42 wrote 1 day ago:
> but what if they could drain every last drop of energy from those
batteries before recycling them?
Again batteries are an energy store and not an energy source. The fact
the author cannot distinguish that makes the their opinion less
credible.
Xemplolo wrote 14 hours 59 min ago:
You are just not able to comprehend basic writing styles.
The author is a journalist and not the expert he is interviewing
thats the first thing. So why would you even evaluate the journalists
'expertise' if you get the answers from the experts.
And secondly what he probalby meant was that what if this company can
'push out' all active lifecycle before they recycle them.
This is called a metapher.
adwn wrote 13 hours 25 min ago:
> And secondly what he probalby meant was [â¦]
If they can't precisely convey the intended meaning in written
words, they shouldn't be a journalist.
Xemplolo wrote 10 hours 47 min ago:
Journalists write for an audiance which normally gets it.
You just might not be one of them.
And no no one needs to write everything so that everyone always
gets it.
I for example do not write blog articles for kids. I also don't
write very technical blog articles for people outside of tech.
adwn wrote 9 hours 4 min ago:
> Journalists write for an audiance which normally gets it.
That's a bullshit justification. "It's factually wrong, but
that's okay, the true audience knows what the author means
anyway." Then why write it at all? It makes no sense. Stop
making up excuses for clueless journalists.
hinkley wrote 1 day ago:
All I can think is embodied energy? Thatâs weird.
almosthere wrote 1 day ago:
We don't need ev batteries for this. We just need cheap enough LifePo4
so we're not burning more shit down. Prismatics from China are a start,
Salt batteries showing some promise next.
dreamcompiler wrote 1 day ago:
This is great! Now I have a place to take my old puffy Li-Ion
batteries.
HTML [1]: https://www.redwoodmaterials.com/recycle-with-us/
torginus wrote 1 day ago:
Personally speaking, having just bought an Ioniq 5 and installing solar
at home what I see as the near future improvement is adding V2L
functionality, which I can hook up to the generator input of my solar
inverter, essentially adding another 60kWh buffer to my grid storage.
Considering how expensive residential batteries are and how quickly EVs
depreciate, I think soon it'll be cheaper to get a used EV as a cheap
source of cells that accidentally happens to be able to drive itself
around.
Imo V2G, and V2H is unnecessary and add too much complication, I think
for the future, solar inverters already have the necessary hardware and
certifications to be able to take power and safely connect to the grid
- something that requires different hardware and standards compliance
in basically every country (yes even within the EU).
sehansen wrote 11 hours 16 min ago:
EVs are probably not going to depreciate as much in the future. The
depreciation mostly happened because new electric cars have become
cheaper.
As an example, let's say a 2 year old car is only worth 80% of an
identical brand new car. The old car was bought for $50k at new,
leading to a expected depreciated value of $40k. But since
manufacturing has become more efficient a brand new car of the same
model can be had for the same $40k. Nobody would be willing to buy
the 2 year old car at the same price. You'd probably have to charge
only $32k [0]. But then it looks to you as if it has depreciated 36%.
The question is how much new electric cars will fall in price in the
future. And if they continue to fall, at some point the dollar value
of the depreciation will be too small to care about.[1]
0: $32k = 0.8 * $40k
1: E.g. if a new car is $10k, $3600 in depreciation over two years is
annoying, but not a big deal.
user_7832 wrote 22 hours 9 min ago:
> Imo V2G, and V2H is unnecessary and add too much complication
I believe that's more a function of auto makers (and charger cos) not
trying to do much about it (and grid cos not caring), than a
technical issue. The benefits (especially if V2G) are quite
significant.
I doubt any car owner will say no to earning revenue from something
that costs them almost nothing. The problem is more of "how do we get
there at scale". (Disclaimer, I studied this topic in my thesis.)
archi42 wrote 1 day ago:
Residential batteries are not that expensive anymore, at least not
all of them.
That's a misconception I also held until a few years ago ;-)
My first 14.3 kWh pack cost about 2800$ DDP from China, delivered
03/2023. For that one I did calculate how long it took for
amortization, which I projected at about 5 years.
The second, identical pack was delivered 08/2024 and cost 2000$ DDP.
Since we got an EV that's drawing about 14kWh per day, I didn't
bother doing the math and just ordered it.
These are 280Ah 16S 51.6V packs, based on the EVE LF280K. In an
enclosure, with a BMS (Seplos, 200A) and a dedicated balancer. They
are good for 6000 cycles at 140A or less [each]. Mind these were both
part of small bulk orders - I think each time we ordered 6 to 8 of
these, which reduced shipping costs.
Hilift wrote 9 hours 32 min ago:
I would take that further and say that residential solar without
batteries has been proven to be a bad solution. Solar with
batteries allows utilities and consumers to schedule when power can
be sent to the grid. California utilities consider solar without
batteries a PITA, and incentive structures have changed to reflect
that shift in policy. [1]
HTML [1]: https://www.canarymedia.com/articles/distributed-energy-re...
HTML [2]: https://enphase.com/blog/homeowners/understanding-nem-30-a...
adwn wrote 22 hours 3 min ago:
Today you can already get 51.2 V, 16 kWh batteries complete with
balancer and BMS from a European supplier for 1200 ⬠(1400 US$):
HTML [1]: https://www.nkon.nl/novat/nkon-ess-eco-s-51-2v-16-1kwh-thu...
SirFredman wrote 16 hours 37 min ago:
And the nice thing is, prices will only get lower. They also have
a 32.15kWh system for â¬3500,- which is insane.
adwn wrote 15 hours 47 min ago:
Unfortunately, almost all three-phase [1] on-grid inverters
that are on the market, especially hybrid inverters, only
support batteries with much higher voltages, like 150 V or even
more.
[1] Three-phase wiring in homes seems to be very rare in the
US, but is extremely common in Europe.
torginus wrote 17 hours 47 min ago:
That looks quite a bit cheaper than the pricing I'm used to
seeing, like less than half - not saying they're bad, but
probably there's a DIY and risk factor involved compared to
buying a more established brand like BYD or Huawei.
I'm just pointing out this is way lower than typical pricing
adwn wrote 16 hours 50 min ago:
Maybe, but I think the premium charged by the main
manufacturer's is unjustifiably high. Those battery boxes are
relatively dumb: besides the cells, they just need some voltage
and temperature sensors for monitoring, some power electronics
for balancing, a microprocessor, and an enclosure with
connectors. Unlike a grid-tied inverter, this is a really
simple system, and there's no way a 500â700% price premium
over the cells is reasonable.
torginus wrote 1 day ago:
My new batteries were about 250EUR/kWh - my 10KWh unit cost 2500
EUR - scaling it up to a decent used 5 year old EV price - you can
have one for 15k with 60+ kWh batteries, so I'd say it's at a very
similar price.
satellite2 wrote 3 hours 34 min ago:
Do you mind citing providers/product names?
kieranmaine wrote 1 day ago:
Very interesting - I did not know this was possible. A few questions:
1. Does the solar inverter do away with the need for a V2G or V2H
unit?
2. What are the limitations vs a dedicated V2G/H unit?
3. Is generator input on your solar inverter a common feature across
inverters?
torginus wrote 1 day ago:
1. It does. The only issue is that the car can only output about
2kW sustained (this is a model limitation). That's fine since I
have batteries in the house.
2. Tbh not super familiar with V2G/V2H, other than it being super
expensive for both the wall box and the car (only high end models
tend to support it)/
3. No idea, but it's not a high end feature, I wouldn't count on
any inverter to just have it, but if you're looking to buy one that
does, I don't think you'll be breaking the bank.
Imo the future is for solar inverters to offer a dedicated DC car
charger port, as once again all the hardware is already in there.
kieranmaine wrote 1 day ago:
Thanks for the answers. I used to work for a EV smart charging
company (Kaluza) that ran a V2G trial. V2G was financial success
for the users, but I always thought the wall box was a potential
blocker. I don't think the 2kW output is a big issue as the
customer could still reduce there load when required, but the
elimination of a wall box makes onboarding much easier.
As long as the inverter can also provide charging this definitely
has some potential.
irons wrote 1 day ago:
In the US, V2L limits your ability to output power from the car to
about 1500 W. It's not going to power your house as more than a
stopgap, even if you do have supplementary house batteries. V2H/V2G
justify their complexity by solving that problem, along with all the
ancillary grid benefits.
Dylan16807 wrote 1 day ago:
A typical house averages less than 1500W. And most of the higher
usage overlaps the sun being out. So if you have supplemental
house batteries to handle bursts then 1500W of V2L can go a very
long way.
eldaisfish wrote 12 hours 40 min ago:
the average hides a lot of information. the largest peak load is
often an electric stove, which is regularly greater than 1,500
kW.
Also, this idea that higher usage overlap with the sun being out
is laughably wrong. Solar noon is between 11 AM and 2 PM. Very
few people are home at that time. There is a reason that peak
grid demand in almost every country is in the early evening.
Dylan16807 wrote 6 hours 46 min ago:
> the largest peak load is often an electric stove, which is
regularly greater than 1,500 kW.
Does that change anything about what I said? This is
specifically about "if you do have supplementary house
batteries".
> Also, this idea that higher usage overlap with the sun being
out is laughably wrong.
The reason we have the duck curve is that insolation and demand
largely overlap (especially when we're talking about the worst
case part of the summer), but then for part of the evening they
really don't overlap.
The peak use is evening, but there's a significant ramp up when
the sun rises and the whole day is much higher than night. [1]
(This isn't the US but finding household graphs in particular
is annoying, and most of the US has more summer heat than
denmark)
Anyway evening is one of those bursts where you use the
supplementary battery to handle the rest of the load. Even
10% of the car's capacity, 6kWh, could cover almost all use
above 1500W.
HTML [1]: https://ars.els-cdn.com/content/image/1-s2.0-S03062619...
eldaisfish wrote 5 hours 48 min ago:
Everything you describe is true only in some places, likely
California. In much of the rest of the world, electricity
demand peaks in the evening, when the sun is low in the sky
and continues well into the evening, when the sun isnât
out. Notice how even the Wikipedia page about the duck curve
lists mainly California. Even in Australia and the UK,
daylight hours and electricity demand mostly do not overlap.
nandomrumber wrote 1 day ago:
> And most most of the higher usage overlaps the sun being out.
Arenât most people at work / school when the sun is out?
Dylan16807 wrote 23 hours 49 min ago:
Yes but high electricity use days correlate with air
conditioning, and most people don't turn that off in the middle
of the day.
If you're not worrying about A/C then 1.5kW goes an extra long
way. Outside of cooking you'll rarely exceed it.
torginus wrote 1 day ago:
Not sure if that's the case - however doing V2L requires the
manufacturer to add an inverter to the car, and making that
powerful probably adds extra cost most customers wouldn't pay. TI
just looked it up and my Ioniq can only do about 2kW sustained -
but since this charges the house battery, that's enough - idle load
is just a couple hundred watts.
nandomrumber wrote 1 day ago:
If the car charges the house battery, what charges the car?
torginus wrote 17 hours 37 min ago:
You pointed out a significant limitation of my current setup -
right now there are 2 plugs - one for discharging the car
through a proprietary manufacturer's V2L adapter, and one for
charging.
I'm planning to make a 'box' that can switch between the 2
functionalities on the same cable.
The whole setup is a bit clunky as it is right, now, but I'm
kinda more surprised that it works at all, and how well the
fundamentals work.
This whole thing was more of an experiment in 'no way you can
do this' to actually doing it, but I think this is HUGE, and
will transform the way people think about electric cars.
irons wrote 23 hours 59 min ago:
If you have solar panels or time-of-use electrical rates, you
charge the car when power is cheap/free, and spend stored power
when the grid costs are high. During a protracted outage, maybe
you drive the car to a fast charger.
iwanttocomment wrote 1 day ago:
I've got a 13 year old EV and nobody has told me how to cash my EV in
for reusable energy storage. (No, seriously, hit me up.)
bryanlarsen wrote 1 day ago:
Just sell it though normal channels. If your battery is with more
than your car then there would be people making money on the
arbitrage.
iwanttocomment wrote 1 day ago:
I totally get that, but as the owner, perhaps I'd like to make the
money on the battery before the arbitragers.
bryanlarsen wrote 9 hours 45 min ago:
People look for used car parts at wreckers. EV batteries are no
different.
hshdhdhehd wrote 14 hours 54 min ago:
Wire it up to a solar panel and use it for home energy?
Xemplolo wrote 14 hours 57 min ago:
You are getting a base price but the rest needs to be enough to
motivate people to handle your batterie and to install it
somewhere.
You can convert your batterie yourself into a grid support
batterie for your own house to maximize your personal gain.
But you are not doing things on scale, so you need to ignore your
personal labor time.
dukeofdoom wrote 1 day ago:
Seems like the market is going the hybrid route. It's kind of easy to
see why, best of both worlds. Some BYD hybrids have crazy ranges like
1500 km on a tank of gas. The more practical car is winning. They put
in a much small battery in these for fast charge, and the daily commute
range. And you have gas, for longer trips. Maybe smaller batteries
would be better for grid-scale storage too. If they're lighter and
easier to handle.
eloisant wrote 17 hours 8 min ago:
No, hybrid is just a temporary solution until the charging
infrastructure becomes good enough. And depending where you live,
it's already there.
Hybrid is the worse of both worlds in a way. You have a combustion
engine to maintain, that is useless when using electricity. You have
a heavy battery useless when using your combustion engine.
You don't get all the benefits of electric, and you don't get all the
benefits of ICE.
sehansen wrote 10 hours 59 min ago:
Exactly this. Here in Denmark, 48k plug-in hybrids were sold in
2020, falling to 4k in 2025. The same numbers for fully electric
cars were 38k in 2020 and 144k in 2025. Once the public charging
infrastructure was here, the change was dramatic. I bought my first
electric car this year and I haven't had trouble finding a public
AC charger when I needed to, which is often since I live in a
condo.
plqbfbv wrote 1 day ago:
> best of both worlds
And the worst too: [1] I don't have first-hand experience, but these
guys have an EV repair shop for a while and do also hybrids, their
articles always offer lots of insight.
Short run down:
- micro/mild hybrids are useless: batteries too small, engines too
small to be the sole source of power, so contribution to emission
reduction is very small, batteries tend to fail early because they're
very small
- full hybrids have bigger batteries and engines large enough to run
pure EV, but you still rely on ICE engine for everything, so there's
no ability to charge at home or save on gas
- plug-in hybrids are full hybrids, but you can charge them
externally; according to many studies the estimated emissions are
much higher than declared, because people simply don't charge them at
home and run on ICE the whole time
In all these types of hybrids the batteries are smaller than pure
EVs, so they cycle faster and degrade faster. You're carrying two
drivetrains all the time with added weight, one of which has plenty
of maintenance items. So they're not drop-in replacements.
From what I've seen from EVClinic above, many manufacturers use
custom pouch cells, not cylindrical modules like the more advanced
pure EVs, so you can't repair an individual failed cell. That means
full pack replacement. For many manufacturers you can't order
replacement parts of the electric drivetrain, and if you do, they
cost a huge chunk of the car.
So all in all if everything's well, you're good. If something goes
wrong, be prepared to spend the same as you would spend for a battery
replacement of a pure EV, or even more.
HTML [1]: https://evclinic.eu/2025/09/27/if-you-drive-a-hybrid-may-god...
pinkgolem wrote 1 day ago:
i have heard that hybrid's have a maintanance problem?
is not a concern, double the technologie in the same space?
numpad0 wrote 1 day ago:
It's not like reliable gas cars ever had substantial maintenance
problem in the gas part. So removing the gas part didn't do much in
practice.
People do/did have frustrations with gas car mannerisms and mental
approachability, like, everything was written in a mix of
translated foreign language documents and borderline insane
gearhead languages. That lead them to imagine that removing the gas
part would drastically change the industry, in their favor.
But, in the end, gas cars are good with regular maintenance for
something like 100k miles over 8 years, so, I wouldn't know what
consumer product were more reliable than a gas car in the first
place.
rgmerk wrote 1 day ago:
Reliable gas cars still require a lot more maintenance than an EV
does.
Oil and oil filter changes. Fuel filters. Air cleaners. Brake
pads (that mostly goes away with hybrids too).
numpad0 wrote 18 hours 2 min ago:
And this is what I'm referring to by approachability issues.
Even HNers can't correctly enumerate maintenance items for a
car.
If I said iPads are better than laptops because there's no need
to regularly replace soft drive Window and repaste NPUs every
2000 hours, everyone knows what kind of person I would be. Yet,
that just casually happen all the time when it comes to EVs.
duskwuff wrote 1 day ago:
Not that I'm aware of. I've heard that many hybrids actually
require less maintenance - for instance, the car can use electric
power for hard acceleration instead of stressing the engine, so oil
tends to last longer, and regenerative braking causes the friction
brakes to wear out more slowly.
toast0 wrote 1 day ago:
Eh, my PHEV has a 2 year oil change interval, which is longer than
my ICE only cars. You should probably bring in your EV every 2
years to get things looked at too.
The engine in a hybrid should live an easier life compared to an
ICE. No extended idle, mostly running in the power band, etc. There
are lots of different ways to setup the hybrid system, but
typically, rather than a small stater motor, you have a larger
motor/generator that also starts the engine; it's less likely to
get worn out, because it's built for continuous use.
In my PHEV, it has a 'toyota synergy' style 'e-CVT' which
eliminates gear selection and should be very low maintenance
(although mine had to be replaced under a service bulletin due to
bearing failure because of manufacturing error) again nicer than an
ICE. But some hybrids have a more traditional transmission.
Certainly, you can do ICE only or EV only, but there's a lot of
room to use the ICE for things it's good for, and the EV for things
it's good for, and blend where there's overlap.
nandomrumber wrote 1 day ago:
That two year oil change cycle is the minumum required to not
void the warranty.
It shouldnât be taken as the optimal interval to maximise
engine life.
Of course, modern fully synthetic engine oils are longer lasting,
and I believe the newer Toyotas, at least the hybrids anyway,
have electric oil pumps, and use very thin engine oil to make
sure the engine is well lubricated at startup.
Marsymars wrote 1 day ago:
Ford Escape? I have a friend that needed the transmission on his
2023 PHEV replaced under warranty... no service bulletin, but
mechanics caught a manufacturing error at a regular service.
Hopeful my hybrid Maverick doesn't have similar problems.
toast0 wrote 21 hours 44 min ago:
2014? Ford C-MAX energi TSB 16-0105 [1] (although there's a
similar TSB 22-2396 [2] with a wider range)
I'd just say, if it starts making bearing noises (loudest
around 15mph), check in and get yelly. Cause apparently they
keep screwing them up. HF35 is designed and built by Ford for
Ford, so they really should have everything they need to do it
right. sigh
I saw a picture somewhere where they had an extra hole carved
through the casing from this, worked fine until it breached and
the fluid came out, then it died pretty quick. [1]
HTML [1]: https://static.nhtsa.gov/odi/tsbs/2016/SB-10092366-544...
HTML [2]: https://www.tsbsearch.com/Ford/22-2396
dukeofdoom wrote 1 day ago:
It's possible it might actually be more reliable long term, once
the technology matures. For example, in cold weather the gas engine
might heat the battery for better battery performance, maybe even
extend its life if it prevents it from being drawn down too much.
The gas engine, would also likely last longer since its not used
for daily commutes.
"In many PHEV systems, there are different modes:
Electric mode (EV mode): The vehicle runs purely on the electric
motor(s) and battery until the battery depletes to some extent.
Hybrid/Parallel mode: Both the petrol engine and electric motor(s)
work together to drive the wheels, especially under high load,
higher speeds or when battery is low.
Ithy
Series mode (in some designs): The petrol engine acts only as a
generator to charge the battery or power the electric motor(s), and
the wheels are driven by the electric motor(s).
For the BYD Leopard 5 (and many BYD PHEVs) the petrol engine can
drive the wheels (i.e., it is not purely a generator). It is part
of the drive system, especially when high power or long range is
needed.
At the same time, it likely can assist with charging the battery or
maintaining battery state of charge (SOC) when needed (for example,
to keep the battery at some reserve level or in âsaveâ mode).
User-reports show that the petrol engine will kick in to support
the electric system, charge the battery, or assist the drive under
certain conditions" -
dukeofdoom wrote 1 day ago:
Not sure about that, since I did never owned one either. But I
watched a review BYD car yesterday. And it's supper nice.
HTML [1]: https://www.youtube.com/watch?v=_6bqgR3NRHE&t=1s
1970-01-01 wrote 1 day ago:
Betteridge's law of headlines finally fails? TL;DR: Yes, but you can
also make it 'not work' if you choose to politicize the tech solution
to the energy problem.
KaiserPro wrote 1 day ago:
> Can "second life" EV batteries work as grid-scale energy storage?
Yes
is it profitable? probably not.
Looking at the price for brid battery storage, and its dropping
precipitously. The cost isn't as much in the batteries them selves, it
packaging, placing and then controlling them.
For example if you want to have a 200Mwhr 100Mw storage site, you'll
need to place it, join it to the grid, all doable. Then you need the
switch gear to make it work as you want it to.
For day ahead, 30 minute trading, thats fairly simple.
For grid stabilisation, thats a bit harder, you need to be able to
lead/match/lag the grid frequency by n degrees instantaneously. which
is trivial at a few kw, much harder at 100Mw
Xemplolo wrote 15 hours 3 min ago:
'probably not'?
Based on what numbers?
Germany alone had to pay 2 billion in dispatch measures to energy
providers. And in the last 6 month we had news about a HUGE request
of companies wanting to build grid stabilisation and grid market
battery systems in a range of over 100GwH.
Also we do have industries which would be able to save a ton of money
if the invest in smaller but similiar systems today already due to
energy prices.
And in germany for example, we do have a lot of wind energy in the
north but not enough live transit capacity to get it into the south.
In this scenario the market would again stabilize the grid by
charging at night from cheap / free wind energy production in north
and transfering it to the south and then using it at day.
nop_slide wrote 1 day ago:
Sounds like what [1] is doing
HTML [1]: https://www.basepowercompany.com/
dylan604 wrote 1 day ago:
Without being a battery chemistry expert, why do these battery packs
become not useful for an EV yet could still be useful for energy
storage. They keep saying that 80% of life becomes unusable for EV, but
that's still a lot of life. Is it that grid energy is more of a
constant drain while the EV is lots of hard pulls (for lack of better
wording)? In an EV, the battery cannot provide the higher volts being
requested within rating, but a grid is never demanding peak
performance?
jillesvangurp wrote 18 hours 3 min ago:
The load in an EV is very different than in storage. Basically the
charge and discharge rate is what deteriorates the battery. EVs need
a lot of power delivered quickly in bursts when you accelerate
(tens/hundreds of kw). And then fast charging when the driver is in a
hurry also puts a lot of stress on the battery. With storage
solutions, the power requirements are much less intense. These high
bursts of energy would actually blow the fuse in your house. They are
simply not needed. And there is no need for fast charging them
either. Instead they get charged over many hours when there is cheap
power available.
Companies like Redwood are good at assessing the state of the battery
and then managing it such that it is run optimally. Usually, it's
just a few cells that are no longer working; the rest of the pack is
still be fine. So that just means the max output of the pack drops a
bit. But that's still more than fine for storage if all you need is a
few kw of output.
Running the battery optimally also extends the useful life of the
remaining cells.
benzible wrote 1 day ago:
It's not just about capacity (80% is still a lot), it's that degraded
batteries lose their ability to deliver high current under loadâso
acceleration suffers and voltage sags under hard pulls. For grid
storage, you're doing slow, steady charge/discharge cycles over
hours, so the same battery that can't handle aggressive driving
anymore works perfectly fine. Plus, grid storage has virtually
unlimited space and no range anxiety, so if you need 25% more packs
to hit your capacity target, you just stack them in a warehouse where
real estate is cheap.
hinkley wrote 1 day ago:
> For grid storage, you're doing slow, steady charge/discharge
cycles over hours.
Only if the feed in is a bottleneck. For peak shaving you could go
faster.
ramses0 wrote 1 day ago:
Looking forward to the grid-scale warehouse fire of battery packs
popping off...
dylan604 wrote 1 day ago:
They claim to have taken the Moss Landing fire into account with
how they are placing their batteries. We won't know if they've
really solved the problem or not until their first battery pack
experiences a runaway thermal event.
miahi wrote 1 day ago:
Also, batteries will degrade faster over time when they start to
degrade, because they need more frequent charging. Their internal
resistance increase and that promotes heat buildup during fast
charging/discharging, another thing that promotes degradation. Slow
charge/discharge cycles also help with heat management.
HWR_14 wrote 1 day ago:
For an EV you want a high energy density, because it impacts range.
For grid storage, density doesn't matter as much.
MarioMan wrote 1 day ago:
Space and weight are serious constraints in the car space, but not
such a big deal on the side of a house. Thatâs how they retain
their usefulness.
80% could indeed be plenty of usable life for your EV use cases, but
it strongly depends on usage patterns. More degradation means more
trips to the charger on a road trip. It means trips that youâd
regularly make just charging at home at the end of day now require
you to plug in at the destination too. It means more range anxiety as
a whole.
bryanlarsen wrote 1 day ago:
This is less useful than most people expected. Redwood has been
struggling because the expected battery turnover is not occurring. EV
batteries are lasting a long time, so they stay in the car are and not
being recycled or reused in any quantity yet.
If EV batteries last 20+ years in EV's, it'll be > 2040 before there
are significant numbers of EV batteries available to recycle or reuse.
HTML [1]: https://www.geotab.com/blog/ev-battery-health/
dzhiurgis wrote 15 hours 40 min ago:
Top it how cheap batteries have gotten it makes little sense to
remanufacture unless you are extremely dedicated DIYer, live
somewhere with very cheap labour or it's done in massive scale to
achieve economies of scale.
In NZ you can get 60KWh used Tesla battery for 6-10k NZD, then spend
another 1-2k for additional gear + labour to hack it (overall
$116-200/KWh) or 15KWh for 3.5k ($233/KWh) with warranty and safety
guarantees.
jillesvangurp wrote 17 hours 18 min ago:
That's part of it. Yet there is a growing gwh of EV batteries that
gets retired on a yearly basis. Which is what Redwood has been
tapping into. There is also a certain amount of cells that don't make
it past the quality gates in the factory that get recycled via them.
Also people forget how quickly EVs have grown. The Tesla Model 3 came
out in 2017; that's eight years ago. That was pretty much the first
mass market EV that got produced by the hundreds of thousands per
year. It had eight years of battery warranty. Most EVs you see on the
road were produced after 2017 and typically come with similar
warranty. The simple reality is that the vast majority of EV
batteries ever produced is still under it's factory warranty and
nowhere near its warranty life time. The amount of gwh of battery
that becomes available for companies like Redwood is fairly
predictable as it is tied to the production volume 8-15 years ago.
Redwood is basically tapping into the growing number of cars that get
scrapped early because of accidents or other failures. That's a
smallish percentage of overall vehicles produced but at the rate EVs
started getting produced around eight years ago, it's starting to add
up to a few gwh of battery per year. It's not a lot yet but it's not
that unpredictable. And it's not nothing. If you manufacturer new
batteries at 80$/kwh, producing 1 gwh new would cost about 80M$. So
giving batteries a second life has quite a bit of economic value. The
issue for Redwood is probably more that competition for these
batteries is quite fierce. There is a lot of valuable stuff you can
do with these things and lots of companies eagerly looking to pick up
second hand EVs for their batteries.
jwr wrote 18 hours 34 min ago:
> the expected battery turnover is not occurring
I find this somewhat amusing, because the black PR of the fossil-fuel
industry would have us believe that EV batteries basically have a
2-year lifespan, cost lots of CO2 to produce, instantly become toxic
waste after those 2 years, are non-recyclable, and overall as a
result EVs emit more CO2 than gasoline-burning cars. We are being
told that EVs have a larger CO2 footprint than gasoline-burners.
Then Redwood shows up with a perfect way to utilize all those
discarded batteries without even opening them up, and⦠that toxic
industrial junk isn't even there?
Theodores wrote 1 day ago:
The typical EV industry trade show has a small handful of cars and a
vast amount of tangential businesses including many finance options,
a vast amount of home charger gizmos, fast charging gizmos,
electricity suppliers and the companies promising grid-scale storage,
either from actively used cars or recycled EV batteries. There is a
vast constellation of this stuff, with specialist insurance companies
that nobody really asked for outnumbering the car brands or even
e-bike brands present.
In time there will be consolidation. This constellation of EV startup
bottom-feeders will be decimated along with the 'excuses' to not make
money.
I don't think the problem is that EV batteries are lasting longer, it
is just that the EV market from before the Model 3 came along is
miniscule. Hence not many second hand batteries to recycle.
As for EV batteries and their availability, when was the last time
you saw an OG Tesla Model S with the fake grill? Those cars used to
be everywhere, but where are they now? The German EVs that came out
to compete, for example, Taycan and eTron, those things are not going
to last the distance since the repairs cost a fortune and the parts
supply is limited.
All considered, there will come a time before 2040+ when there are
large quantities of these electric car batteries to upcycle, by which
time the EV business will be consolidated with only a few players.
If there was money in recycling cars then every auto manufacturer
would be in on it.
JumpCrisscross wrote 1 day ago:
> Redwood has been struggling because the expected battery turnover
is not occurring
Redwood pitched recycling. But its principal business was primary
production. (Processed black mass is analogous to lithium ore.)
They're struggling because demand for American-made batteries remains
low.
JohnLocke4 wrote 1 day ago:
In 2040 fusion energy advancements will have gotten far enough to be
the next technological step and make this redundant anyway
throwaway270925 wrote 19 hours 37 min ago:
With solar, fusion energy is already here! There is just a bit of
wireless transmission involved after generation.
megaman821 wrote 1 day ago:
The steam generator that the fusion generator connects to might be
more expensive than solar at this point. That would be even if
fusion cost nothing and had infinite amounts of fuel, there would
be no customers for its energy on a sunny afternoon.
bee_rider wrote 1 day ago:
This is like a âfusion is only 20 years awayâ (or 15 in this
case) joke, right?
hinkley wrote 1 day ago:
It used to be 30. So fifty more years?
marcosdumay wrote 1 day ago:
Yep, it was 30 years at the 60s. If it keeps halving every 85
years, we'll get it approximately never :)
hinkley wrote 1 day ago:
Zeno's Fusion Paradox
epistasis wrote 1 day ago:
There's currently no technological path for fusion to be cheaper
than fission. It would require a technological breakthrough that we
have not yet imagined.
And already, solar plus storage is cheaper than new nuclear. And
solar and storage are getting cheaper at a tremendous rate.
It's hard to imagine a scenario where fusion could ever catch up to
solar and storage technology. It may be useful in places with poor
solar resources, like fission is now, but that's a very very long
time from now.
BurningFrog wrote 1 day ago:
The regulatory hurdles are probably bigger than the difficult
enough technological ones you mention.
apendleton wrote 1 day ago:
> It would require a technological breakthrough that we have not
yet imagined.
Maybe, but not necessarily. The necessary breakthrough might have
been high-temperature superconducting magnets, in which case not
only has it been imagined, but it has already occurred, and we're
just waiting for the engineering atop that breakthrough to
progress enough to demonstrate a working prototype (the magnets
have been demonstrated but a complete reactor using them hasn't
yet).
Or it might be that the attempts at building such a prototype
don't pan out, and some other breakthrough is indeed needed.
It'll probably be a couple of years until we know for sure, but
at this point I don't think there's enough data to say one way or
the other.
> And already, solar plus storage is cheaper than new nuclear.
It depends how much storage you mean. If you're only worried
about sub-24h load-shifting (like, enough to handle a day/night
cycle on a sunny day), this is certainly true. If you care about
having enough to cover for extended bad weather, or worse yet,
for seasonal load-shifting (banking power in the summer to cover
the winter), the economics of solar plus storage remain abysmal:
the additional batteries you need cost just as much as the ones
you needed for daily coverage, but get cycled way less and so are
much harder to pay for. If the plan is to use solar and storage
for _all generation_, though, that's the number that matters.
Comparing LCoE of solar plus daily storage with the LCoE of
fixed-firm or on-demand generation is apples-and-oranges.
I think solar plus storage absolutely has the potential to get
there, but that too will likely require fundamental breakthroughs
(probably in the form of much cheaper storage: perhaps something
like Form Energy's iron-air batteries).
cesarb wrote 14 hours 2 min ago:
> If the plan is to use solar and storage for _all generation_,
though, that's the number that matters.
And that's the problem with these Internet discussions: that's
almost never the plan, but commenters trying to make solar look
bad assume it is (to your credit, you made it explicit; many
commenters treat it as an unspoken assumption).
In real life, solar and batteries is almost always combined
with other forms of generation (and other forms of storage like
pumped hydro), in large part due to being added to an already
existing large-scale grid. The numbers that matter are for a
combination of existing generation (thermal power plants,
large-scale hydro, etc) with solar plus storage. Adding
batteries for just a few hours of solar power is enough to
mitigate the most negative consequences of adding solar to the
mix (non-peaking thermal power plants do not like being cycled
too fast, but solar has a fast reduction of generation when the
sun goes down; batteries can smooth that curve by releasing
power they stored during the mid-day peak).
bruce511 wrote 21 hours 2 min ago:
One can discuss base load and season shifting all day long. But
ultimately fusion will fail for two simple reasons; time and
money.
If we started building a fusion commercial scale plant today
(ie started by planning, permits, environmental assessments,
public consultation, inevitable lawsuits, never mind actual
construction and provisioning) it'd come online in what? 10
years? 15 years? 20 years?
Want to deploy more batteries? It can be online in months. And
needs no more construction than a warehouse.
Financially fusion requires hundreds of billions, committed
now, with revenue (not returns) projected at 10 years away
(which will slide.) Whereas solar + storage (lots and lots of
storage) requires anything from thousands to billions depending
on how much you want to spend. We can start tomorrow, it'll be
online in less than 2 years (probably a lot less) and since
running costs are basically 0, immediate revenue means
immediate returns.
Of course I'm not even allowing for fusion being "10 years"
from "ready". It's been 10 years from ready for 50 years. By
the time it is ready, much less the time before it comes
online, it'll be redundant. And no one will be putting up the
cash to build one.
adrianN wrote 22 hours 42 min ago:
In the end we're still making steam and running a turbine. Just
the steam turbine part of the power plant has a hard time
competing with solar in sunny locations.
pfdietz wrote 1 day ago:
High temperature superconducting magnets are not a panacea for
the problems with DT fusion. Those issues follow from limits
on power/area at the first wall, and the needed thickness of
the first wall; these ensure DT reactors will have low
volumetric power density, regardless of the confinement scheme
used.
With HTSC magnets, a tokamak much smaller than ITER could be
built, but ITER is so horrifically bad that one can be much
better than it and still be impractical.
pfdietz wrote 9 hours 12 min ago:
> needed thickness of the first wall
I meant, needed thickness of the tritium breeding blanket.
apendleton wrote 1 day ago:
Oh for sure, I'm not claiming that CFS (or Tokamak Energy or
Type One or whoever else) will for sure succeed, or if they
do, that they've already solved all the problems that will
need solving to do so. My only assertion/prediction is that I
think if they end up succeeding, when future historians look
back and write the history of this energy revolution or
whatnot, HTSC magnets will turn out to have been the key
breakthrough that made it possible.
nandomrumber wrote 1 day ago:
Fusion reactors are self destroying, just ask any star.
More seriously: what to do about the neutron flux
destroying the first wall inside the reactor vessel?
epistasis wrote 1 day ago:
And these are not new issues, they've been known for more
than 40 years, but never addressed. From the 1983 Led
> But even though radiation damage rates and heat transfer
requirements are much more severe in a fusion reactor, the
power density is only one-tenth as large. This is a strong
indication that fusion would be substantially more expensive
than fission because, to put it simply, greater effort would
be required to produce less power.
HTML [1]: https://orcutt.net/weblog/wp-content/uploads/2015/08...
apendleton wrote 1 day ago:
In terms of cost of materials to build a reactor, sure,
that seems right. But most of the cost of fission is
dealing with its regulatory burden, and fusion seems on
track to largely avoid the worst of that. It seems
conceivable that it ends up being cheaper for entirely
political/bureaucratic reasons.
epistasis wrote 1 day ago:
Regulatory costs and waste disposal are not significance
cost centers for nuclear, at least as far as I can tell
from any cost breakdowns.
One doesn't need super high quality welding and concrete
pours becuase of regulations as much as the basic desire
to have a properly engineered solution that lasts long
enough to avoid costly repairs.
Take for example this recent analysis on how to make the
AP1000 competitive: [1] There are no regulatory changes
proposed because nobody has thought of a way that
regulations are the cost drivers. Yet there's still a
path to competitive energy costs by focusing hard on
construction costs.
Similarly, reactors under completely different regimes
such as the EPR are still facing exactly the same
construction cost overruns as in the rest of the
developed world.
If regulations are a cost driver, let's hear how to
change them in a way that drives down build cost, and by
how much. Let's say we get rid of ALARA and jack up
acceptable radiation levels to the earliest ones
established. What would that do the cost? I have a
feeling not much at all, but would like to see a serious
proposal.
HTML [1]: https://gain.inl.gov/content/uploads/4/2024/11/D...
pfdietz wrote 11 hours 20 min ago:
> let's hear how to change
One approach would be to reduce the size of the
containment building by greatly reducing the volume of
steam it must hold. This would be done by attaching
Filtered Containment Venting Systems (FCVS) that strip
most of the radioactive elements from the vented steam
in case of a large accident.
The containment building is a significant cost driver,
costing about as much as the nuclear island inside of
it.
If such a system had been attached to the reactors that
melted down at Fukushima exposure could have been
reduced by maybe two orders of magnitude. And if the
worst case exposure is that low, perhaps much more
frequent meltdowns could be tolerated, allowing
relaxation of paperwork requirements elsewhere.
epistasis wrote 9 hours 14 min ago:
Interesting! Would that require any regulation
change?
pfdietz wrote 9 hours 3 min ago:
I believe the NRC currently requires that the
containment remain leak-free for 24 hours after a
design basis accident.
Now, I have not checked if shorter lived
radioisotopes would ruin the idea I'm suggesting.
It's possible.
pfdietz wrote 1 day ago:
Relaxed regulatory burden doesn't seem to be making
fission competitive in China; renewables are greatly
overwhelming it now, particularly solar.
We might ask why regulations are so putatively damaging
to nuclear, when they aren't to civil aviation. One
possibility is that aircraft are simply easier to
retrofit when design flaws are found. If there's a
problem with welding in a nuclear plant (for example)
it's extremely difficult to repair. Witness the fiasco
of Flamanville 3 in France, the EPR plant that went many
times over budget.
What would this imply for fusion? Nothing good. A
fusion reactor is very complex, and any design flaw in
the hot part will be extremely difficult to fix, as no
hands on access will be allowed after the thing has
started operation, due to induced radioactivity. This
includes design or manufacturing flaws that cause mere
operations problems, like leaks in cooling channels, not
just flaws that might present public safety risks (if any
could exist.) The operator will view a smaller problem
that renders their plant unusable nearly as bad as a
larger problem that also threatens the public.
I was struck by a recent analysis of deterioration of the
tritium breeding blanket that just went ahead and assumed
there were no initial cracks in the welded structure more
than a certain very small size. Guaranteeing quality of
all the welds in a very large complex fusion reactor, an
order of magnitude or more larger than a fission reactor
of the same power output, sounds like a recipe for
extreme cost.
cyberax wrote 22 hours 21 min ago:
Regulation is not a problem, and even the construction
costs are not terrible. We can take the Rooppur NPP as
a base, it produces reliable energy at 6-7 cents per
kWh. The reason for cost overruns is simply because
NPPs are one-off products, the Western countries don't
have a pipeline for NPP production.
For comparison, utility-scale solar with 16 hours of
storage is 21 cents: [1] Just raw solar without storage
can be as low as 2-3 cents per kWh.
HTML [1]: https://www.utilitydive.com/news/higher-renewa...
apendleton wrote 21 hours 23 min ago:
> The reason for cost overruns is simply because NPPs
are one-off products
But there's no fundamental reason they _have_ to be
one-off products. They just historically have been
for at least partly regulatorily motivated reasons:
because each reactor's approval process starts afresh
(or rather, did until quite-recent NRC reforms),
there's little advantage in reuse, and because many
compliance costs are both high and fixed, there's an
incentive to build fewer huge reactors rather than
more small ones, which makes factory construction
difficult to achieve and economies of scale hard to
realize.
pfdietz wrote 14 hours 14 min ago:
Civil engineering involves adapting any design to
the local geology. This has to be custom for each
site.
pfdietz wrote 21 hours 57 min ago:
If I understand correctly, the cost/year of an
engineer in India is maybe 1/3rd that in the US, and
for general labor the disparity is even larger. So
it shouldn't be too surprising NPP construction in
India is cheaper than in the US. India doesn't have
a large NPP pipeline, they just have cheaper labor.
cyberax wrote 19 hours 25 min ago:
(Bangladesh, not India)
Yes, but solar power panels are also mostly
produced in China, where engineers still get less
than 1/3 of the US/Europe salary.
European power plants will be more expensive, but
even with the LCOE of 12 (twice that of Rooppur)
it's still going to be way cheaper than storage for
areas that get cold weather (Midwest, Germany, most
of China).
Anything south of California? Yeah, just get
solar+wind, no need to bother with nuclear.
pfdietz wrote 14 hours 27 min ago:
As we pointed out, PV is still trouncing nuclear
in China. So if the difference is smaller there,
it's still in favor of solar.
Storage is another matter here, but even there
costs for batteries have simply collapsed.
Understand that massive storage is needed even in
a nuclear-powered economy. If all the 283
million cars and trucks in the US were replaced
with 70 kWh BEVs, the storage would be enough to
power the US grid (at its current average
consumption) for 40 hours. That's a lot of
batteries. So the demand is there to continue to
drive them down their experience curves. In
China, they're already around $50/kWh for
installed grid storage systems (not just cell
price).
The final storage problem, the only reed that
nuclear can be clinging to at this point, is long
term/seasonal storage. That's needed either to
smooth wind variability (~ week scale) or to move
solar from summer to winter (~6 months). There
are at least two different ways this could be
solved: hydrogen and heat. As mentioned
elsewhere in these threads, the latter is very
promising, with capex as little as $1/kWh of
storage capacity and a RTE of about 40%. Should
that work out anywhere close to that nuclear
would be in a hopeless position anywhere in the
world, even at very high latitudes.
cyberax wrote 7 hours 14 min ago:
> As we pointed out, PV is still trouncing
nuclear in China. So if the difference is
smaller there, it's still in favor of solar.
Sure. Solar is easy to scale when you don't
care about reliability, nobody is arguing with
that. But it's another issue entirely when you
need a stable grid.
I'm not aware of any countries (even tropical
ones) that managed anything close to 100%
renewables with solar. E.g. Hawaii has to pay
for extremely expensive diesel generation even
though they have plenty of solar potential.
pfdietz wrote 4 hours 9 min ago:
And nuclear is scalable if you force other
sources off the grid in favor of nuclear (and
force customers to not use renewables "behind
the meter").
In a fair grid, solar and wind get built out,
and the residual demand has no baseload
component. Unless nuclear is given the right
to force other sources off the grid it
becomes inappropriate.
In Texas now there is no chance of new
nuclear construction. ERCOT is a competitive
market and new nuclear simply doesn't make
sense.
cyberax wrote 3 hours 7 min ago:
> And nuclear is scalable if you force
other sources off the grid in favor of
nuclear (and force customers to not use
renewables "behind the meter").
Not really? Nuclear is not any different
from coal. And plenty of countries have
coal generation in the mix. France also is
majority-nuclear.
And so far, nuclear is the second known
technology (after hydro) that actually
demonstrated close to 100% fossil-free
grid.
So far, there is nothing similar for solar.
Even though it's supposed to be
oh-so-cheap.
> In Texas now there is no chance of new
nuclear construction. ERCOT is a
competitive market and new nuclear simply
doesn't make sense.
Well, yeah. Because they can just allow the
grid to die during the next Arctic air
blast.
Dylan16807 wrote 1 day ago:
Fission is expensive for regulation reasons more than
technological reasons, so if fusion doesn't face the same
barriers then it could be cheaper than fission.
But I agree that it doesn't look like fusion is going to be cheap
any time soon.
bryanlarsen wrote 1 day ago:
Fission is also expensive for several mundane reasons, like the
fact that massive steam turbines are expensive, and because any
large construction project in the West is expensive. Neither
fusion nor regulatory reform are going to solve those.
noosphr wrote 1 day ago:
The low energy future that was envisioned is not happening.
The AI arms race, which has become an actual arms race in the war
in Ukraine, needs endless energy all times a day.
China is already winning the AI cold war because it adds more
capacity to its grid a year than Germany has in a century.
If we keep going with agrarian methods of energy production don't
be surprised that we suffer the same fate as the agrarian
societies of the 19th century. Any country that doesn't have the
capability to train and build drones on mass won't be a country
for long.
epistasis wrote 1 day ago:
You have that exactly backwards: solar + storage is what will
give us energy abundance at less money than we could ever
imagine from nuclear fission or fusion.
China is winning the AI Cold war because it's adding solar,
storage, and wind at orders of magnitude more than nuclear.
I'm not sure who's doing your supposed "envisioning" but there
is no vision for cheap abundant energy from fusion. Solar and
storage deliver it today, fusion only delivers it in sci fi
books.
Nuclear is 20th century technology that does not fit with a
highly automated future. With high levels of automation,
construction is super expensive. You want to spend your
expensive construction labor on building factories, not
individual power generation sites.
Building factories for solar and storage lets them scale to a
degree that nuclear could never scale. Nuclear has basically no
way of catching up.
noosphr wrote 1 day ago:
China has been building out nuclear capacity at 5% a year for
25 years.
Solar and wind capacity had shot through the roof in the last
five years because they can't sell hardware to the west any
more.
The other big item is hydro power, which China has a ton of
untapped potential for. Unfortunately for the West every good
river has already been damed so we can't follow them there.
bryanlarsen wrote 9 hours 47 min ago:
> Unfortunately for the West every good river has already
been damed so we can't follow them there.
You don't need a river for hydro power storage. All you
need are two reservoirs with a height difference between
them. Typically one of the two reservoirs is preexisting
and the second is constructed. ANU identified ~1 million
potential sites.
HTML [1]: https://re100.eng.anu.edu.au/global/
ben_w wrote 11 hours 24 min ago:
> Solar and wind capacity had shot through the roof in the
last five years because they can't sell hardware to the
west any more.
They can't sell as much as they would like, specifically to
the USA, due to tariffs/trade war, but there's a much
bigger world out there than just the US, and the overall
exports are up over the last five years: [1] There's a
Chinese-made Balkonkraftwerk sitting a few meters away from
me on my patio, it cost â¬350, of which â¬50 was delivery
and another â¬50 was the mounting posts, the remaining
â¬250 got me 800 W of both panel and inverter.
> Unfortunately for the West every good river has already
been damed so we can't follow them there.
For generation, yes. For storage, no.
HTML [1]: https://www.canarymedia.com/articles/solar/chart-c...
epistasis wrote 1 day ago:
> Solar and wind capacity had shot through the roof in the
last five years because they can't sell hardware to the
west any more.
"can't sell hardware??" hah! I've never heard that weird
made-up justification, where did you pick it up from?
China installed 277GW of solar in 2024, capacity factor
corrected that's 55.4 GW of solar power. That's equivalent
to the entire amount of nuclear that China has ever built.
One year versus all time. And then in the first half of
2025, China installed another 212GW of solar. In six
months.
Nuclear is a footnote compared to the planned deployment of
solar and wind and storage in China.
Anybody who's serious about energy is deploying massive
amounts of solar, storage, and some wind. Some people that
are slow to adapt are still building gas or coal, but these
will be stranded assets far before their end of life.
Nuclear fusion and fission are meme technologies, unable to
compete with the scale and scope that batteries and solar
deliver every day. This mismatch grows by the month.
cyberax wrote 22 hours 30 min ago:
> China installed 277GW of solar in 2024, capacity factor
corrected that's 55.4 GW of solar power.
The problem is not just the mean capacity factor, but the
capacity factor in _winter_. It's terrible for China,
less than 15%. And more importantly, you can have _weeks_
with essentially zero solar power when you need it most.
ben_w wrote 11 hours 1 min ago:
> It's terrible for China, less than 15%.
55.4 GW per 277 GW is an (annual) capacity factor of
20%, so the response here is "yes, and?"
> And more importantly, you can have _weeks_ with
essentially zero solar power when you need it most.
Half the country is a mid-latitude desert. What makes
you think the whole country has "weeks" with zero
solar? And it does have to be the whole country in this
case, because one thing a centrally planned economy can
do well is joining up the infrastructure, which in this
case means "actually make the power grid the USA and
the EU keep wringing their hands over".
cyberax wrote 7 hours 12 min ago:
> Half the country is a mid-latitude desert. What
makes you think the whole country has "weeks" with
zero solar?
The "whole country" is irrelevant. You can't transmit
arbitrary amounts of power across the large
geographic areas, most of energy has to be generated
in a reasonably close proximity.
> And it does have to be the whole country in this
case, because one thing a centrally planned economy
can do well is joining up the infrastructure
Transmission lines are expensive, regardless of your
ideology.
ben_w wrote 7 hours 1 min ago:
> The "whole country" is irrelevant. You can't
transmit arbitrary amounts of power across the
large geographic areas, most of energy has to be
generated in a reasonably close proximity.
Only technically correct because you said
"arbitrary": it's well within China's manufacturing
capabilities to make a grid that can transmit 3 TW
over 40,000 km, with a conductor cross section so
thick it only has 1 Ω resistance.
As in: all the world's current electricity demand,
the long way around the planet.
I have, in fact, done the maths on this.
> Transmission lines are expensive, regardless of
your ideology.
"Expensive" but not "prohibitively expensive".
All infra is "expensive". Nations have a lot of
money.
cyberax wrote 2 hours 38 min ago:
> Only technically correct because you said
"arbitrary": it's well within China's
manufacturing capabilities to make a grid that
can transmit 3 TW over 40,000 km, with a
conductor cross section so thick it only has 1 Ω
resistance.
And it'll turn out to cost more than building a
nuke in each backyard.
> I have, in fact, done the maths on this.
No.
noosphr wrote 22 hours 3 min ago:
This is not an issue in China as they overprovision
demand by 50 percent. Their grid can run off baseload
generation alone in their 2060 plan.
Trying to explain that a grid build by electrical
engineers, rather than financial engineers, has
resilience build in to people whose whole idea about
electricity generation is greenwashed bullshit from
McKinsey and Co is at best a waste of time and at worst
an excellent way to raise one's blood pressure.
pfdietz wrote 1 day ago:
> sci fi books
I blame these for the unquestioned belief that fusion is
desirable. It's a trope because it enables stories to be
told, and because readers became used to seeing, not because
science fiction has a good track record on such things.
The fact that the volumetric power density of ARC is 40x
worse than a PWR (and ITER, 400x worse!) should tell one that
DT fusion at least is unlikely to be cheap.
With continued progress down the experience curve, PV will
reach the point where resistive heat is cheaper than burning
natural gas at the Henry Hub price (which doesn't include the
cost of getting gas through pipelines and distribution to
customers.) And remember cheap natural gas was what
destroyed the last nuclear renaissance in the US.
formerly_proven wrote 1 day ago:
It's hard to imagine a form of energy production less
desirable than fusion.
Okay, sure, burning lignite and using the exhaust as air
heating in the children's hospital. You got me.
p0w3n3d wrote 1 day ago:
Tesla batteries fail after 8 years at least from models up to 2014
Sohcahtoa82 wrote 1 day ago:
[citation needed]
trhway wrote 1 day ago:
Prius Plugin 2015 (last year of that model) - full charge/discharge
at least 3-4 times a week, currently still a bit more than 80% of
capacity (granted the battery seems somewhat overbuilt, yet it is
normally does 10-15C which is much tougher mode than in a pure EV
where 2-3C is usually enough and only high-end Teslas and the likes
would do 5-6C). There has been large continuous improvement in
lithium batteries over the last couple decades.
nandomrumber wrote 1 day ago:
What does any of this mean?
What is c in this context?
dtgriscom wrote 1 day ago:
From my model airplane experience, I believe it's "capacity per
hour". So, a 1Ah battery discharged at 1c would mean 1 amp;
discharged at 10c would be 10 amps. The higher the C, the
harder the batteries are being used.
trhway wrote 1 day ago:
1 C current fully discharges battery in 1 hour. Thus 4KWh
battery running 60 KW engine means 15C current, and it would
discharge the battery in 4 minutes (in a very simplified linear
model).
stetrain wrote 1 day ago:
The number of Teslas sold up to 2014 is less than 1% of all Teslas
sold.
Tesla has an 8-year battery and drivetrain warranty but they don't
necessarily fail after that date.
p0w3n3d wrote 18 hours 55 min ago:
there is an ubiquitous failure of Panasonic-created cells for
Tesla. I made a research on forums, because I wanted one, and
investigated why there is such a price drop. Cars getting close
to the age of 8 years immediately drop on price to even 10k usd.
It's because if you get your battery replaced on warranty - you
won. Otherwise it often deteriorates suddenly.
stetrain wrote 6 hours 41 min ago:
Itâs understandable that people would avoid out of warrant
EVs, we donât have that many years of data on old EVs yet.
Anecdotal forum posts are not a great source of statistical
data.
p1necone wrote 1 day ago:
> "most people"
"most people" even now are just parroting dumb FUD they read on
facebook.
You really shouldn't give any weight to the opinions of laypeople on
topics that are as heavily propagandized and politically charged as
renewable energy.
whatever1 wrote 1 day ago:
We are only 5-6 years into the car ev market. Tesla model 3 started
being sold in 2018 in meaningful numbers
cogman10 wrote 1 day ago:
Still have mine. Battery capacity is around 80% of the new
capacity. I'm not planning on switching anytime soon as it's got
plenty of range still. I'll probably swap the pack out when it
hits 70% in the next 2 or 3 years.
beAbU wrote 19 hours 22 min ago:
Your 2018 tesla has a battery SOH of 80%?
How many km's on the clock, and how often do you fast charge if
you dont mind me asking?
To me that SOH stat sounds really bad!
cogman10 wrote 14 hours 1 min ago:
270,000 km. And fast charging about 3 times a year.
If I were to guess, the main factor harming the battery is my
garage gets pretty hot in the summer (37 or 38C)
rconti wrote 10 hours 22 min ago:
I'm not even sure how to calculate our deg! Same, 2018 3 long
range. I think they advertised it as 305mi but some time
later increased the capacity of the car to 315mi; I max
charged it to 314 once but never quite saw that 315. I think
we're around 273 as max now so 89.5% of the original quoted
life, 87% of the "updated" life. Car has 115k miles, ~
185,000km.
cogman10 wrote 10 hours 1 min ago:
There was about 2 years of rapid drop off that I
experienced and I don't exactly know why.
beAbU wrote 12 hours 52 min ago:
That is quite high mileage. I'm certain someone smarter and
less lazy than me can calculate the amount of expected cycles
that the battery would have seen.
Do you leave it fully charged for long periods of time, or do
you discharge it down to empty or nearly empty quite
regularly?
cogman10 wrote 12 hours 44 min ago:
I charge it to 70% and leave it there most of the time.
I don't often fully discharge, that's bad for the lipos. I
usually keep a 40-70 range SOC.
dzhiurgis wrote 15 hours 36 min ago:
I agree, reads like carefully crafted FUD.
cogman10 wrote 13 hours 58 min ago:
What possible motivation would I have to spread FUD about my
own car?
To me this is perfectly reasonable degradation after 7 years
of ownership with the number of miles I have.
There is also just an element of luck that's involved.
Batteries degrade at different rates and there's not really
any accounting for it.
bryanlarsen wrote 1 day ago:
It probably will take a lot longer than that to hit 70%.
Degradation on Tesla batteries slows down considerably after it
hits 85%.
there are exceptions, though.
ACCount37 wrote 1 day ago:
A lot of the early EV battery life projections were based on Nissan
Leaf Gen 1. Which had a horrendous battery pack that combined poor
choice of chemistry, aggressive usage and a complete lack of active
cooling.
When EVs with good battery pack engineering started hitting the
streets, they outperformed those early projections by a lot. And by
now, it's getting clear that battery pack isn't as much of a concern
- with some of the better designs, like in early Teslas, losing about
5-15% of their capacity over a decade of use.
numpad0 wrote 1 day ago:
It didn't just had horrendous service life, it was designed for
some set years of life to be regularly replaced and repurposed for
battery storages. Nissan had business schemes outlined for that
with Leaf packs.
I think Tesla deserves credit for rethinking hat model into
chassis-life battery packs and surpluses rather than recovered
cells for grid storages.
Especially considering that, resales of Gen1 Leafs milked for EVs
and renewables incentives is like destination fees atrocious. You
can find fairly zero-milage ones with a functional 100-yard battery
pack on sale for couple hundred dollars in some places. Even
crashed wrecks of a Tesla cost magnitudes more.
sandworm101 wrote 10 hours 2 min ago:
A car chassis is essentially immortal: 30, 40 or even 100+ years.
Modern steal is franky amazing compared to cars of the past.
Tesla batteries are nowhere near chassis life numbers.
I was stuck in traffic behind an 87 caddy yesterday. It was not
a collector car. That chassis is still on the road, seemed to be
taking kids to school.
hnuser123456 wrote 8 hours 16 min ago:
I see you don't live in Michigan... my 22 year old car has
growing rust holes in front of the rear wheels.
guelo wrote 1 day ago:
That's amazing good news for the environment, thank you I hadn't
heard this.
jbm wrote 1 day ago:
I am a bit more concerned about batteries now as opposed to an year
ago.
We had this article from Elektrek [1] about battery issues in South
Korea. When I asked my local electric maintenance shop [2, sorry
for the FB link], they said they have started seeing the same issue
in Model 3s and Ys in Canada as well. (They also said that it is
too early to tell how common it would become)
This may bode well for recycling since the issues is an unbalance,
not the whole pack failing. [1]
HTML [1]: https://electrek.co/2025/10/14/tesla-is-at-risk-of-lossing...
HTML [2]: https://www.facebook.com/groups/albertaEV/posts/2485588442...
jgilias wrote 15 hours 29 min ago:
Idk, not really worried about that. There are shops that are able
to swap out a faulty module, and the cost is not too horrible:
HTML [1]: https://www.reddit.com/r/electricvehicles/comments/1e3on...
MetaWhirledPeas wrote 23 hours 23 min ago:
I would be more concerned if the source were anyone but
Electrek~. Their vendetta against Tesla has forfeited all their
credibility on Tesla news.
"many of these vehicles are now out of warranty, as they
sometimes exceed the maximum mileage"
They have good numbers for the number of affected vehicles, but
the best they can do for out-of-warranty stats is "many" and
"sometimes". Convenient.
~To be fair this applies to a lot of popular tech sites I used to
respect. Dunking on Tesla is its own industry these days, it
seems.
CursedSilicon wrote 19 hours 6 min ago:
>Dunking on Tesla is its own industry these days, it seems.
Are you suggesting Tesla is criticized without good reason?
jack_pp wrote 16 hours 54 min ago:
Idk enough but I assume there are good reasons, however when
a website is biased and finds even bad reasons to hate that's
still a problem right?
fragmede wrote 4 hours 42 min ago:
Bad reasons to hate something are bad press for Tesla, and
how many people are going to read past a headline that
confirms their bias? This isn't limited to Tesla, mind you,
and is a broader statement on clickbait, and the state of
the Internet and media and society today. Of course,
anybody on Tesla's side knows to take Electrek and the rest
of the Inernetâs coverage with a grain of salt, but with
rabid fanboys on both sides, it's hard to know how large a
grain of salt, and when.
cowsandmilk wrote 14 hours 21 min ago:
What are the bad reasons that bias electrekâs coverage?
bryanlarsen wrote 9 hours 55 min ago:
Electrek's Fred has a ton of Tesla referral credits.
Tesla owes him 2 Roadster's and has reneged. After
Tesla screwed him, Fred's coverage turned from glowing to
negative.
1234letshaveatw wrote 12 hours 32 min ago:
extremist "journalists" and/or undisclosed sponsorship?
Contrast their Tesla coverage with their almost giddy
stories on anything China related.
jbm wrote 19 hours 8 min ago:
I can respect that. For what it is worth, I validated with a
well-trusted local shop that works on EVs (and works with
Tesla) that said the issue is starting to pop up. Moreover,
it's the government of Korea that is making this claim as well.
(I also find it difficult to separate noise from signal about
Tesla. However, I don't consider them innocent victims;
besides the elephant in the room, they literally eliminated
their PR department)
seanmcdirmid wrote 1 day ago:
Tesla made powerwalls a product for a reason. They were supposed
to come from outdated Tesla cars, but that never materialized. If
it is materializing now, they already know what they are going to
do.
floxy wrote 1 day ago:
Don't forget that the original Leaf pack was only 24 kWh. So if
you assume a ~1000 full-equivalent-charge-cycles lifespan, then the
large Gen2 62 kWh pack will live 2.5 times longer than an original
24 kWh pack. If you average 3.5 miles/kWh, the 24 kWh battery
will be expected to last somewhere around 84,000 miles. While the
62 kWh pack will last for 217,000 miles.
HTML [1]: https://coolienergy.com/lfp-vs-nmc-batteries-the-science-b...
bryanlarsen wrote 7 hours 34 min ago:
This is a big reason why hybrid's are generally a bad idea.
Their batteries wear out a lot quicker than the batteries on
EV's.
floxy wrote 7 hours 11 min ago:
The batteries in a hybrid are much smaller (~1.3 kWh for a
Prius), and so cost much less to replace.
bryanlarsen wrote 6 hours 44 min ago:
The vast majority of EV owners will spend $0 to replace their
batteries since the batteries last longer than the rest of
the car does.
Edit: part of that is that a Prius with 250,000 miles needing
its second battery replacement is still a valuable car with a
reasonable expectation of a lot more miles. OTOH a Tesla
at 250,000 miles needing its first battery replacement...
Similarly Chrysler hybrid owners spend less money on battery
replacements than Toyota hybrid owners. Not a compliment,
it means they're scrapping their cars earlier.
adrianN wrote 22 hours 53 min ago:
Why would you only assume 1000 cycles? Is the chemistry that bad?
The LFP battery on my balcony is rated for 5000 cycles iirc.
Moto7451 wrote 22 hours 15 min ago:
LFP does have a lot more cycles in them by the nature of the
chemistry. However EV grade NMC arenât terrible either.
Depth of discharge and charge rate affect LFP specifically in
such a way that if you keep them a good margin above cutoff
voltage, relatively cool (60C and under, and do 1C and lower
charging you can get 10,000 cycles per their data sheets. The
same sheets will also list lower cycle counts for harder use
that lines up with the standards used for earlier cells.
Basically I think weâll find a lot of gently to moderately
used hardware will last a long time.
Whatever a believable use case looks like will probably end up
on those data sheets and it wouldnât surprise me if we see
15,000 and 20,000 cycles advertised for cells intended in low
charge and discharge use cases (probably not cars but maybe
home energy storage).
My Taycan has an ongoing battery issue relating to LG Pouch
cells but its construction rather than composition that is the
culprit. The same compositions from LG in prismatic and
cylindrical models, the only models they sell now, so far
havenât been a mess for car makers.
jopsen wrote 12 hours 8 min ago:
We did 12.000 km in our id.4 last year.
I suspect it'll die due to rust. But yes, might take a while.
Even in Denmark where we salt the roads in a winter.
cogman10 wrote 1 day ago:
I'll defend the leaf a little.
LiPo batteries were quiet expensive when it was initially released.
NiMH was really the only option in town.
And with a lower energy density battery that's also heavier, adding
a cooling system would have also added a bunch of weight to the
already heavy car with a barely usable range of 100 miles.
Gen 2, however, had no excuses. They had every opportunity to add
active cooling and they still decided to go with just air cooling.
cptskippy wrote 23 hours 14 min ago:
> Gen 2, however, had no excuses. They had every opportunity to
add active cooling and they still decided to go with just air
cooling.
The Lizard pack in the later Nissan Leafs has held up
surprisingly well. I have a 2015 that still gets 75 miles of
range. I'm sure they thought it wasn't necessary and they
probably had the actuarial numbers to justify it.
xattt wrote 1 day ago:
NiMH was used in Priuses for a very long time, and these seem to
have lasted for ages.
ACCount37 wrote 1 day ago:
Leaf Gen 1 didn't have NiMH. It had a lithium-based battery
chemistry, but some bastard offshoot of it. One that really
didn't fare well under high current draw, or deep discharge, or
high temperatures, or being looked at wrong.
trainsarebetter wrote 3 hours 34 min ago:
1st gen was LMO
MrRadar wrote 1 day ago:
Every generation of the production Nissan Leaf has used lithium
batteries. AFAIK no modern (~post-2000) mass-produced (>10k units
sold) EV has ever used NiMH or lead-acid batteries.
Edit: Checking Wikipedia to verify my information, I found out
that Nissan actually sold a lithium-battery EV in 1997 to comply
with the same 90s CARB zero-emissions vehicle mandate that gave
us the GM EV-1:
HTML [1]: https://en.wikipedia.org/wiki/Nissan_R%27nessa#Nissan_Al...
formerly_proven wrote 1 day ago:
EVs no, but I think some Toyota hybrids (which are of course
not even PHEVs) still use NiMH. Toyota tends to be very
tight-lipped about their batteries and their sizes (or rather,
lack thereof).
whaleofatw2022 wrote 9 hours 19 min ago:
Early Hybrids used NiMH because Chevron was holding on to a
lot of the patents around using Lithium Ion for the purpose
IIRC.
numpad0 wrote 1 day ago:
Tends to be tight lipped??? It is in the catalog[1]! It is
more that American consumers aren't tech obsessed than Toyota
being reluctant to share.
Even just looking at online media reports[2][3] clearly
sourced from some exact same press event, it is obvious that
US English equivalents are much lighter in content than
Japanese versions. They're putting the information out, no
one's reading it. It's just been the types of information
that didn't drive clicks. Language barrier would have effects
on it too, that Toyota is a Japanese company and US is an
export market, but it's fundamentally the same phenomenon as
citizen facing government reports that never gets read and
often imagined as being "hidden and withheld from public
eyes", just a communication issue.
1: [1] 2: [2] 3:
HTML [1]: https://www.toyota.com/priuspluginhybrid/features/mp...
HTML [2]: https://www.motortrend.com/news/toyota-aqua-prius-c-...
HTML [3]: https://car.watch.impress.co.jp/docs/news/1339263.ht...
formerly_proven wrote 18 hours 26 min ago:
Despite your ??? and ! the only article you posted that's
about hybrids (and not PHEVs) mentions nothing about
battery capacity.
close04 wrote 12 hours 6 min ago:
> Battery capacity (kWh) 13.6
It's under Weights/Capacities but you have to expand the
section yourself, no way to link directly to it.
formerly_proven wrote 11 hours 42 min ago:
The page you are referring to is literally titled
"Plug-In Hybrid Specifications"
/out
close04 wrote 10 hours 32 min ago:
Sorry, I just saw you objected to the lack of
information for battery capacity, not the type of
hybrid or chemistry.
taneq wrote 19 hours 52 min ago:
Interestingly they don't tell you anything (unless I missed
it) about the battery for the non-plugin hybrids, eg. the
Corolla Cross: [1] I was looking up this year's Corolla a
while ago and likewise there was minimal info that I could
see about the battery capacity, which I think I figured out
was about 3kWh.
HTML [1]: https://www.toyota.com/corollacross/features/mpg_o...
avhception wrote 1 day ago:
It's nice to get a reminder about this problem once in a
while, I've fallen into the trap myself at times.
wcfields wrote 1 day ago:
On the used market you'll find absolutely cooked (literally)
Leafs whose first life was in Arizona and barely have enough
range to back out of the driveway.
jbm wrote 19 hours 0 min ago:
Is there any value in fixing the battery on these? IE: Do the
other components last long enough to be worth the cost?
It seems like procuring the battery is not as expensive as the
Tesla battery (I see someone who did it themselves for $6k on
Youtube with the battery from a wrecked leaf). In comparison,
the cost I see for my Model 3 is about ~$18k CAD.
Getting a car up and running for $8k might be worth it if it is
otherwise dependable, but I've only heard unfortunate stories
about the first gen Leaf.
bluGill wrote 12 hours 43 min ago:
Is it worth spending money on a car that old? You are putting
more than the car is worth into fixing it and you won't get
that back if you sell. You also have no idea when/if
something else will go. thew worst case is the day after you
fix it someone hits you and the repairs will be $30,000 -
what it cost new and there are still a lot of worn out parts:
insurance will give you $4000 and tell you to eat the loss.
trainsarebetter wrote 3 hours 33 min ago:
30000? What? Leaf packs are swap able between years⦠here
in bc 2k and you have a newer pack in
bluGill wrote 2 hours 46 min ago:
30k is the real cost to repair some accident damage to a
leaf - think bent frame. this could happen anytime.
Nobody would pay that price to the whole car ends up in a
junk yard.
londons_explore wrote 1 day ago:
I have a gen 1 leaf with a remaining range of about 500 yards
if you drive gently...
I use it in my driveway to make it look to thieves like someone
is home (round me, houses with no car get broken into).
Marsymars wrote 1 day ago:
Sounds like an old Roomba I used to have that could clean for
about 2 minutes before it ran out of juice.
dylan604 wrote 1 day ago:
From TFA:
David Roberts
When did automotive batteries become the majority of your input by
volume?
Colin Campbell
That is a good question.
David Roberts
Was it recent or was that early on?
Colin Campbell
I would say the transition to EV batteries dominating what we
received, itâs been in the last year or 18 months.
David Roberts
So the front edge of a very large wave of batteries has begun to
arrive?
Colin Campbell
Yeah, the wave is out there, itâs coming. The waters have finally
started to arrive at the beach here.
jeffbee wrote 1 day ago:
He's just talking his book. Their deployment this year was 1/4000th
share of the BESS market.
dylan604 wrote 1 day ago:
Battery Energy Storage System for anyone else like me that has no
knowledge of this world and their acronyms.
bryanlarsen wrote 1 day ago:
Reading between the lines of the corporate speak will validate my
point. Redwood was founded in 2017.
dylan604 wrote 1 day ago:
"Itâs the largest microgrid in North America and itâs the
largest second-energy storage site in the world. So thatâs like
you said at the top, itâs a 12-megawatt AC, 63-megawatt-hour
grid supporting about 2 or 3 megawatts of data centers and run by
solar. So all the energy comes from another 12 megawatts of
solar."
Sure, so while not supplying power to a city, they are proving
this is viable. Just because it's not "turn off the coal plants
now" moment doesn't mean this isn't a very good direction.
Everyone has to start and grow. I don't understand the whole shit
on something because it's not an immediate solve. If these guys
waited until 2040 to start the business, well, that'd just be
dumb. It essentially sounds like capacity will just continue to
increase year over year, maybe around 2040 there will be a huge
spike. Doesn't seem like anything is wrong here.
pfdietz wrote 1 day ago:
So, basically the same reason recycling of PV modules hasn't taken
off.
Rebelgecko wrote 1 day ago:
I've been intrigued by used solar panels for sale, seems like you
can get an amazing price for ones that are only lightly degraded.
Is there a downside, or do you just mean that it isn't popular
currently?
bityard wrote 8 hours 44 min ago:
Used panels are cheap because of where we are in the improvement
curve. Let's say you're a large business with a factory rooftop
full of 100W panels that was installed installed 10 years ago.
Today, you can upgrade that rooftop to 300W panels without any
additional footprint and often for less than the original
deployment cost (adjusted for inflation).
Those old panels have to go somewhere and still have at least 2/3
of their life left. Probably more because we're finding out that
well-made panels do not degrade as quickly as previously thought.
The used panel market (in the US anyway) might dry up soon if the
tariffs stay in place, as that will make a lot of customers
reluctant to upgrade due to greatly increased costs. But I guess
we'll see. I've been wrong before.
duskwuff wrote 1 day ago:
How much of a difference does it actually make in terms of the
all-inclusive price of installation (e.g. panels, inverters,
mounting hardware, and labor)?
(Asking because I genuinely don't know, not because I have a
specific answer in mind.)
Rebelgecko wrote 1 day ago:
Labor is by far the top cost. But I'm intrigued by the
economics of a small setups paired with like a <5kwh battery.
And for something like that where you literally just throw 4-6
panels out, you can just brute force by buying more panels
instead of optimizing angles. Basically a slightly beefier
version of a European balcony setup
hinkley wrote 1 day ago:
Find an installer who will warranty work using third party let
alone used solar panels and then we can talk.
hnaccount_rng wrote 1 day ago:
In addition to my sibling comment: The cost of the panels is a
rather small fraction of the total cost of a typical
installation. Most of that cost ist labor, some regulatory
requirements and the inverter. Whether you pay a factor of 2 for
the panels or not typically doesn't matter. In other words:
Reusing used panels will only ever be able to safe you a
minuscule amount.
ericd wrote 1 day ago:
Yeah, we paid more for the little bits of metal that held up
the panels than for the panels themselves (aluminum, but
still).
dzhiurgis wrote 15 hours 33 min ago:
IDK sounds like you got ripped off. I diy'd and panels were
cheap of course, but fittings were perhaps 3-5x cheaper.
Inverter is typically same as your panels (hybrid, grid-tied
are quite a bit cheaper).
ericd wrote 13 hours 25 min ago:
Maybe, but these arenât fittings, theyâre ground mounts
with large screws that screw into the ground to hold the
entire array down, including under high wind (and have to
come with PE stamped system-level engineering drawings
talking about things like rated wind load of the whole
array to pass building inspections).
But yeah, at the end of the day, just bent bars of aluminum
with ground screws and bolts to hold the corners of the
panels, versus the technological marvels of the solar
panels they hold.
namibj wrote 13 hours 48 min ago:
For all of your context/reference, if you buy whole pallets
from a central European port warehouse, glass-glass modules
run around $0.11/Wp plus shipping.
Unless you're just bolting them to the floor or to an
uninsulated wall, mounting will (sadly) run you a sizable
fraction of that cost in the best case.
hinkley wrote 1 day ago:
These days itâs a stack of microinverters. Which are not
cheaper but do improve array efficiency outside of idea
conditions. But thatâs another up front cost.
pfdietz wrote 1 day ago:
The low cost of the modules themselves has led to the
suggestion of cost optimized DC-coupled PV systems being used
to directly drive resistive heaters. The cost per unit of
thermal energy in a cost optimized system moderate scale system
(> residential, < utility scale) may be in the range of
$3-5/GJ, very competitive with natural gas. Low cost maximum
power point trackers would be useful; inverters would not be
needed.
Low cost modules allow one to do away with things like
optimally tilted modules and single axis tracking. The modules
can also be tightly packed, reducing mounting and wiring costs.
jopsen wrote 11 hours 3 min ago:
I've heard of farmers doing this, well I think they actually
had an inverter. But limits on how much they could dump into
the grid, meant that they had lots of surplus electricity and
installing resistive heating was very cheap.
Even if they don't have surplus electricity all the time.
alvah wrote 22 hours 53 min ago:
Is it worth using heat pumps in this setup (in addition to
resistive elements)? I understand they can't reach the
absolute temperature of resistive heating, but from an
efficiency POV for the first few tens of degrees they are
much more efficient.
kragen wrote 9 hours 27 min ago:
Efficiency allows you to use less solar panels, but more
solar panels are cheaper than a heat pump. I think the
ratio is about 5:1 at this point and widening.
kragen wrote 5 hours 32 min ago:
To be concrete, I'm told that recently in the US a
certain 34000btu/hour (10kW) output heat pump consuming
up to 14A at 220V at the compressor (3kW) cost US$2700
installed, which is 27¢ per peak watt of output. But
[1] gives a price of â¬0.055 per peak watt (US$0.065/Wp)
for low-cost solar panels. So the heat pump costs, in
some sense, 4.2 times as much as the solar panels.
But the heat pump doesn't save you 10kW over resistive
heating when it's running full-tilt. It saves you 10-3 =
7kW. So it costs 39¢ per watt of saved energy, which is
6 times as much as the solar panels.
In some simplified theoretical sense, if you decide you
need another 10kW of heating for your house, you could
spend US$2700 on this heat pump, and also buy 3000 Wp of
solar panels to power it, costing US$194, for a total
cost of US$2894. Or you could buy 10000 Wp of solar
panels, costing US$645, and a resistive wire, costing
US$10, for a total cost of US$655. US$655 is almost five
times cheaper than US$2894. (4.4 times cheaper.)
There are a lot of factors that this simplified cost
estimate overlooks; for example:
⢠Maybe you need to run the heater 16 hours a day but
you only get sunlight 7 hours a day, either because it's
winter in Norway, or because there are tall pine trees
that shade your property most of the day, and you can't
put the panels up on the trees. So maybe in some sense
one watt of peak heater output is worth 2.3 watts of peak
solar panel output. Or maybe it's the other way around,
where your house only needs active heating during a few
hours at night, so one watt of peak heater output is only
worth 0.43 watts of peak solar panel output.
⢠The prices are in different countries. Solar panels
are more expensive in the US, even wholesale.
⢠US$2700 is the retail price of the heat pump,
including installation and warranty, and 6.5¢/Wp is the
wholesale price of low-cost solar panels with no warranty
("Minderleistungs-Solarmodule, B-Ware, Insolvenzware,
Gebrauchtmodule, PV-Module mit eingeschränkter oder ohne
Garantie, die in der Regel auch keine Bankability
besitzen.") Even in Europe the retail price of solar
panels is three or four times this.
⢠Driving a resistive heating element from solar panels
is considerably easier than driving a heat pump from
solar panels; adapting a heating element to run on lower
voltage is just a matter of connecting more wires to the
middle of it, while adapting a heat pump to run on lower
voltage may involve redesigning the whole power supply
board or even rewinding the motor. Which is in a
hermetically sealed refrigerant circuit, by the way,
which you'd have to reseal. In practice, you'd just buy
an inverter, but a 3000-watt inverter is expensive.
⢠As you said, for sensible-heat thermal storage, the
heat pump craps out at about 50° or 60°, while any
garden-variety resistive heating element (plus a lot of
crappy improvised ones) will be just fine at 600° or
700°. That means you need ten times as much thermal
mass for the same amount of storage. Sand is dirt cheap,
but once you get into the tens of tonnes, even dirt isn't
really cheap.
Despite such complications, I still think that pair of
numbers is a useful summary of the situation: the heat
pump costs 39¢ per watt saved, while the solar panel
costs 6.5¢ per watt produced.
HTML [1]: https://www.solarserver.de/photovoltaik-preis-pv...
bluGill wrote 12 hours 26 min ago:
Depends - the problem with heat pumps is when you need them
the most they don't work. If it never gets below -10c
(exact temperature needs more study, could be as low as
-25) where you live they are fine - but that implies you
live in an area where you don't get many cold days and so
the expense isn't worth it (it also implies you live where
it gets hot in sumner so you want ac anyway and the
marginal additional cost makes it worth it again). If you
live in an area where it gets colder you need additonal
backup heat that can cover those really cold days and so
you may as well run that system only.
pfdietz wrote 3 hours 43 min ago:
I think unless you're in an area dominated by cooling
needs, an optimally sized heat pump system will not cover
100% of heating needs. It would make sense to make it
smaller and use a backup resistive heater for rare very
cold events.
bluGill wrote 2 hours 48 min ago:
cooling is more important but not by much. however the
real problem is temperature delta: 100f-70f is 30
degrees, 70f-10f is 60 degrees. If you size a system
for cooling it can't make up.
of course things arenot actually linear on temperature
but as a rough estimate it gets the point across.
maxerickson wrote 1 day ago:
What's the proposed system design? For example, in January, I
get about 9 hours of sunlight and have an average daily high
of 25 F. I'm gonna need to store heat somehow or another.
kragen wrote 23 hours 31 min ago:
I haven't seen pfdietz's proposed system design, but a
so-called "sand battery," consisting of a box of sand with
a heating element running through it, should work fine.
You can PWM the heating element with a power MOSFET to keep
it from overheating; you can measure its temperature with
its own resistance, but also want additional thermocouple
probes for the sand and to measure the surface of the box.
A fan can blow air over or through the sand to control the
output power within limits.
I'll work out some rough figures.
Let's say your house is pretty big and badly insulated, so
we want an average of 5000 watts of heating around the
clock with a time constant on the order of 10 hours, and we
don't want our heating element to go over 700°.
(Honest-to-God degrees, not those pathetic little
Fahrenheit ones.) That way we don't have to deal with the
ridiculous engineering issues Standard Thermal is battling.
There's a thermal gradient through the sand down to room
temperature (20°) at the surface. Suppose the sand is in
the form of a flat slab with the heating element just
heating the center of it, which is kind of a worst case for
amount of sand needed but is clearly feasible. Then, when
the element is running at a 100% duty cycle, the average
sand temperature is 360°. Let's say we need to store
about 40 hours of our 5000W. Quartz (cheap construction
sand) is 0.73J/g/K, so our 720MJ at ÎT averaging 340K is
2900kg, a bit over a cubic meter of sand. This costs about
US$100 depending mostly on delivery costs.
The time constant is mostly determined by the thickness of
the sand (relative to its thermal diffusivity), although
you can vary it with the fan. The heating element needs to
be closely enough spaced that it can heat up the sand in
the few hours that it's powered. In practice I am guessing
that this will be about 100mm, so 1.5 cubic meters of sand
can be in a box that's 200mm à 2.7m à 2.7m. You can
probably build the box mostly out of 15m² of ceramic
tiles, deducting their thermal mass from the sand required.
In theory thin drywall should be fine instead of ceramic
if your fan never breaks, but a fan failure could let the
surface get hot enough to damage drywall. Or portland
cement, although lime or calcium aluminate cement should be
fine. You can use the cement to support the ceramic tiles
on an angle iron frame and grout between them if necessary.
7.5m² of central plane with wires 100mm apart requires
roughly 27 2.7m wires, 75m, probably dozens of broken hair
dryers if you want to recycle nichrome, though I suspect
that at 700° you could just use baling wire, especially if
you mix in a little charcoal with the sand to maintain a
reducing atmosphere in the sand pore spaces. (But then if
it gets wet you could get carbon monoxide until you dry it
out.) We're going to be dumping the whole 720MJ thermal
charge in in under 9 hours, say 5 hours when the sunshine
is at its peak, so we're talking about maybe 40kW peak
power here. This is 533 watts per meter of wire, which is
an extremely reasonable number for a wire heating element,
even a fairly fine wire in air without forced-air cooling.
If we believe [1] the thermal conductivity of dry sand
ranges from 0.18 W/m/K to 0.34 W/m/K. So if we have a
linear thermal gradient from our peak design temperature of
700° to 20° over 100mm, which is 6800K/m, we should get a
heat flux of 1200â2300W/m² over our 15m² of ceramic
tiles, so at least 18kW, which is more than we need, but
only about 3Ã, so 200mm thickness is in the ballpark even
without air blowing through the sand itself. (As the core
temperature falls, the heat gradient also falls, and so
does the heat flux. 720MJ/18kW I think gives us our time
constant, and that works out to 11 hours, but it isn't
exactly an exponential decay.) Maybe 350mm would be
better, with corresponding increases in heating-element
spacing and decreases in wire length and box surface area
and footprint.
To limit heat loss when the fan is off, instead of a single
humongous wall, you can split the beast into 3â6 parallel
walls with a little airspace between them, so they're
radiating their heat at each other instead of you, and
cement some aluminum foil on the outside surfaces to reduce
infrared emissivity. The amount of air the fan blows
between the walls can then regulate the heat output over at
least an order of magnitude. (In the summer you'll
probably want to leave the heating element off.)
The sand, baling wire, aluminum foil, lime cement, angle
irons, charcoal, thermocouples, power MOSFETs,
microcontroller, fans, and ceramic tiles all together might
work out to US$500. But the 40kW of solar panels required
are about US$4000 wholesale, before you screw them to your
siding or whatever. At US prices they'd apparently be
US$10k.
720MJ is 200kWh in cursed units, so this is about
US$2.50/kWh. Batteries are about US$80/kWh on the Shanghai
Metals Market.
What do you think?
HTML [1]: https://www.nature.com/articles/s41598-025-93054-w...
formerly_proven wrote 18 hours 59 min ago:
Did you just reinvent electric night storage heaters?
kragen wrote 18 hours 46 min ago:
I would instead say that, familiar with many designs
from millennia of history of using thermal mass for
indoor climate control, I outlined a design of an
electric night storage heater that is especially cheap
and convenient. Or an "electric day storage heater", I
guess, since the day is when it stores heat.
kragen wrote 20 hours 47 min ago:
A thing I forgot to calculate: with 75m of wire
dissipating 533 watts per meter, how thick should the
wire be? Suppose we divide it into three 25m circuits so
that we still have most of our heat if a wire burns out,
and suppose we're using 48Vdc. So E²/R = 13.3kW, R =
E²/13.3kW = 0.173Ω, and each of those elements is
carrying an astonishing 277 amps. So we want 7 milliohms
per meter. It turns out that that's about 12-gauge
copper wire, nominally 5 milliohms per meter. 2
millimeters across. A higher-resistivity metal like iron
or nichrome would have to be even thicker.
Better idea: put 9 2.7-meter wires in parallel on each of
the three circuits, so each wire can have 9Ã0.173Ω =
1.56 Ω = 0.58Ω/m. That's 32-gauge copper magnet wire,
0.2mm diameter, 0.54Ω/m; or its thicker equivalent in
other metals. Iron's resistivity is 5.7 times copper's,
so you need a 5.7 times thicker wire: 0.5mm, 24-gauge.
Nichrome is 11 times the resistivity of iron, so you'd
need 1.6-mm-diameter nichrome.
I don't know, I think the copper would probably melt
faster than the sand could conduct the heat away from it,
and the nichrome would definitely be fine, but too
expensive. But you can extrapolate from this how to
solve the problem: by shortening the distance along the
heating wires to low-resistance busbars (possibly made of
rebar or leftover angle iron) and thus increasing the
number of parallel paths, you allow the use of
higher-resistance-per-unit-length and thus cheaper and
more workable heating elements; the limit of this
lightweighting is that the wires' surface area in contact
with the sand must cool them enough to prevent melting.
By this method you can use a small amount of a conductor
of any resistivity at all, limited mainly by the
temperature.
All these metals are fine at 700°, or for that matter
1000°. Copper will have less of a tendency to oxidize
than iron, which would require a reducing atmosphere, and
nichrome will oxidize but remain protected by its
oxidation. (A reducing atmosphere will destroy
nichrome.) But, at a lower temperature still, like
600°, you could use 10μm thick household aluminum foil,
which is much easier to work with than any kind of 20μm
wire, but has a similar ratio of surface area to volume.
It has 54% more resistivity than copper, so a 10μm Ã
1mm strip is 2.7 ohms per meter. Our previous objective
of 0.58Ω/m is a 4.6mm-wide-strip, which transfers heat
to the sand along its 9.2mm perimeter, like a 10-gauge
wire. 75m à 4.6mm is the size of about 5 or 6 pages of
A4 paper cut into strips.
sandy234590 wrote 15 hours 48 min ago:
Maybe stainless steel for the heating elements and
busbars?
Cheaper than nichrome and copper. I feel like mild
steel would not last long in practice.
Copper plated MIG welding wire might be good enough?
Probably want to think about thermal expansion also,
especially configured as "walls", and with skins
considerably colder than cores.
pfdietz wrote 13 hours 52 min ago:
Austin Vernon claims they have a very cheap resistor
material for Standard Thermal but hasn't said what it
is. I look forward to hearing that detail when it
leaks out. A good chunk of their work while in
stealth was on the resistors, I understand.
kragen wrote 9 hours 29 min ago:
I think I've shown above that you can make the
resistor material itself almost arbitrarily cheap,
calculating for example how you can get 40
kilowatts out of 9.3 grams of aluminum foil, and
showing that with more busbars you can use even
less resistor material than that. Aluminum itself
wouldn't work for Standard Thermal's target
temperatures, but you can make an arbitrarily thin
foil out of any metal, supporting it as a thin film
on an insulating ceramic such as porcelain if
necessary. Copper, gold, silver, mild steel,
nickel, nichrome, other stainless, titanium,
platinum, and platinum/iridium, could all be made
to work, and in no case would the material cost be
significant. Metal film resistors supported on
ceramic are being used to convert electrical energy
into heat in probably every electronic device in
your house.
And the old standby for resistive heating of giant
piles of dirt, for example to bake it into
carborundum, isn't a metal at allâit's plain old
carbon, which you can if necessary bake in situ.
Carborundum itself can also work, though it's not
malleable, and controlling its resistivity can be
tricky.
MIG welding wire is an interesting possibility.
The main potential obstacle, I think, is the
manufacturing cost, and as sandy234590 was saying,
potentially durability in use. Vernon said
resistor durability had been one of their major
problems; I'd think that sand would impose less
stress on the resistors than generic dirt, but,
with quartz in particular, you could greatly reduce
the risk by not crossing the quartz dunting
temperature at 573°: [1] That obviously isn't an
option for Standard Thermal, but it would be
completely viable for household climate control,
just requiring somewhat more sand.
Sandy points out, implicitly, that mild steel such
as the baling wire I suggested typically does not
last long at high temperatures. But that's because
it oxidizes. The same vulnerability is present in
most metals, though not silver, gold, platinum, and
platinum/iridium alloys, and only to a limited
extent for nickel, nichrome, and other stainlesses.
That oxidation can only happen in an oxidizing
atmosphere; the thin iron ballast wires in Nernst
lamps last indefinitely because they're sealed in a
reducing (hydrogen) atmosphere. As I said, I think
you can maintain a reducing atmosphere in the sand
pore space by just including a little charcoal,
which will scavenge any oxygen that gets close to
the heating elements when they're hot, and may even
be able to reduce any oxide that does form, at the
cost of carbon monoxide emission.
If the atmosphere inside the sand is oxidizing,
you'd probably want to either use something that
won't be damaged by oxidization, such as gold or
nichrome, or use a very thick heating element such
as carbon so that it will have an adequate service
life despite the oxidation. Most stainless steels
will start to oxidize at a few hundred degrees,
even though they're fine at room temperature.
(The main heating element in Nernst lamps, cubic
zirconia, was also immune to oxidation, but it had
some other drawbacks; for example, it needed to be
preheated into its conductive range with a platinum
preheat wire, and its rather aggressive negative
temperature coefficient of resistance made it prone
to thermal runaway when operated on a
constant-voltage sourceâthus the iron ballast
wire.)
HTML [1]: https://digitalfire.com/glossary/quartz+in...
pfdietz wrote 23 hours 25 min ago:
Sand batteries have a much higher cost per unit of energy
storage capacity, so they are in more direct competition
with batteries for shorter term storage. It's hard to
compete with a storage material you just dig out of a
local hole. The economics pushes toward crude and very
cheap.
Having said that: a good design for sand batteries would
use insulated silos, pushing/dropping sand into a
fluidized bed heat exchanger where some heat transfer gas
is intimately mixed with it. This is the NREL concept
that Babcock and Wilcox was (still is?) exploring for
grid storage, with a round trip efficiency back to
electricity of 54% (estimated) using a gas turbine.
Having a separate heat exchanger means the silos don't
have to be plumbed for the heat exchange fluid or have to
contain its pressure.
Getting the sand back to the top (where it will be heated
and dropping into silos) is a problem that could be
solved with Olds Elevators, which were only recently
invented (amazingly).
HTML [1]: https://www.youtube.com/watch?v=-fu03F-Iah8
kragen wrote 22 hours 23 min ago:
(I completed my parent comment since you wrote your
response, which may make it confusing to read your
response; sorry about that.)
I agree that local dirt is much cheaper than trucked-in
construction sand, but I think my design sketch above
shows that a "sand battery" whose only moving parts are
fans will be about 30Ã cheaper than a real battery at
household scale, even though the sand is still most of
the estimated cost. A "sand battery" designed to power
a steam turbine is a much more difficult problem to
solve, but in this case the stated problem is just that
it's 24°F (-3°) outside, so I think much cheaper
solutions are fine, with no pressure vessels, stainless
steel, insulated silos, sand conveyors, or heat
transfer fluids other than garden-variety air.
Do you have a good handle on the pressure (and
therefore power) requirements for getting air to flow
upward through sand? I feel like you ought to be able
to get a pretty decent amount of thermal power out of
half a tonne of sand with a really minimal amount of
pumping, but that's only a gut feeling. Definitely as
you go to graded-granulometry gravel the required head
drops off to almost nothing.
Thanks for the link to the Olds device! That's utterly
astounding. Archimedes could have used it for raising
sand, although making a sturdy enough tube out of wood
might have been a bit of a chore.
pfdietz wrote 1 day ago:
The place I saw this most clearly described was in Standard
Thermal's concept, which will store the heat in huge piles
of dirt heated to 600 C. The thermal time constant of such
piles can be many years. [1] [2]
HTML [1]: https://www.orcasciences.com/articles/standard-the...
HTML [2]: https://austinvernon.substack.com/p/building-ultra...
HTML [3]: https://news.ycombinator.com/item?id=45012942
cyberax wrote 22 hours 35 min ago:
I ran the numbers on that, and it just doesn't work.
Stone has rather lousy specific heat capacity (less than
1kJ/kg/K, compared to 4.2kJ for water).
A typical house in Midwest needs around 22,000kWh
(7.913Ã10^10 J) over the winter (75 million BTU - [1] ).
If we assume the delta of 550 degrees (600 down to 50),
you'll need: 7.913Ã10^10 J / (550K * 1000Jkg^-1K^-1) =
143,872,727 kg of material in your pile. This is a
ridiculously stupid number. And I don't see any obvious
mistakes?
HTML [1]: https://www.eia.gov/todayinenergy/detail.php?id=...
pfdietz wrote 14 hours 38 min ago:
Your decimal point slipped three places in that last
calculation; the result is too high by a factor of
1000.
A more worthy criticism is that the pile for just a
single house is too small and would cool off too
quickly.
cyberax wrote 9 hours 32 min ago:
I don't believe it did? Delta of 550 degrees Kelvin
multiplied by 1000J per kg per Kelvin.
maxerickson wrote 7 hours 59 min ago:
You have 8*10^10 in the numerator and 5*10^5 in the
denominator, so the result should be roughly
8/5*10^5.
Still big number.
pfdietz wrote 8 hours 47 min ago:
7.913e10 / ( 5.5e2 * 1.0e3 ) = 1.438e5, not 1.438e8
When doing calculations like this I just fire up a
lisp and enter the thing to be calculated as lisp
form.
kragen wrote 4 hours 38 min ago:
I use units(1), which also helps me avoid
dimensional errors (dividing when I should have
multiplied, etc.):
You have: 7.913e10 J / 550K / (1J/g/K)
You want: kg
* 143872.73
/ 6.9505876e-06
maxerickson says, "Still big number," and 144
tonnes would typically be an unwieldy quantity of
material if you had to buy it. But Standard
Thermal's intention is not to buy dirt, just pile
up already-on-site dirt with a bulldozer or
excavator. If we assume 1.3 tonnes/m³, that's
110m³, or, in medieval units, 144 cubic yards.
[1] tells us:
> An excavator could be used to dig anywhere from
350 to 1,000 cubic yards per day, depending on a
number of factors including bucket capacity, type
of ground, operator skill and efficiency level,
and more. (...)
> One of the biggest factors that impact how much
an excavator can dig in one day is the unitâs
bucket size, which typically ranges from 0.5 to
1.5 cubic yards of bucket capacity. Most common
regular-size excavators have a 1 cubic yard
bucket capacity, and mini excavators are closer
to the 0.5 cubic yard capacity.
So, with this number, we're talking about a few
hours of work for a "mini excavator". [2] tells
us that a "4,000 lb. mini excavator" rents for
US$197 per day. So the expense of moving the
dirt is not really significant, compared to other
household projects such as replacing the roof,
insulating the walls, or repainting the exterior.
Standard Thermal mentions that they are in effect
firing the clay in the ground, that they've had
significant trouble with resistance-heater
reliability, and that their objective is to power
steam-turbine power stations with the stored
heat. These three facts lead me to believe that
they're targeting a temperature closer to 1000°
than to 600°.
HTML [1]: https://www.eaglepowerandequipment.com/b...
HTML [2]: https://www.bigrentz.com/rental-location...
pfdietz wrote 3 hours 46 min ago:
600 C is about what a coal fired power plant
would use. And 600 C is around the maximum
that you want if you're using cheap steel for
the pipes. Much beyond that and creep becomes
a problem. So I don't think 1000 C is their
target.
kragen wrote 3 hours 44 min ago:
Hmm! Interesting! I would have thought that
600° would be close to the minimum for
producing supercritical steam, so any energy
stored up to 600° would be "overhead" that
couldn't be effectively recoveredâonly the
heating above that. And I assumed they would
have to use cheap ceramic for the pipes,
because oxidation is usually a problem for
cheap steel even below 600°.
pfdietz wrote 3 hours 41 min ago:
The critical temperature of water is 374 C.
kragen wrote 3 hours 31 min ago:
You're right; I wonder why they operate
supercritical steam turbines at 600°
instead? [1] [2] [3] Oh, apparently
because of "dramatic improvements in
power plant performance":
> Starting with the
traditional 2400 psi / 1000 F (165 bar /
538 C)
single-reheat cycle, dramatic
improvements in
power plant performance can be achieved
by
raising inlet steam conditions to levels
up to
4500 psi/310 bar and temperatures to
levels in
excess of 1112 F/600 C. It has become
industry
practice to refer to such steam
conditions, and
in fact any supercritical conditions
where the
throttle and/or reheat steam temperatures
exceed 1050 F/566 C, as
âultrasupercriticalâ. [4] Anyway,
those are the plants that Standard
Thermal wants to sell their
product/service to. And once the hot
dirt falls below 600°, it can no longer
heat the water to 600°. So I think they
have to be aiming far above that
temperature, which is also why heating
element reliability is a challenge and
why the clays in the soil are firing (a
phenomenon which only happens at 600°
for the lowest-firing terra-cotta clays,
more typically requiring
1000°â1400°).
HTML [1]: https://direns.minesparis.psl.eu...
HTML [2]: https://www.mdpi.com/2673-7264/5...
HTML [3]: https://www.modernpowersystems.c...
HTML [4]: https://www.gevernova.com/conten...
pfdietz wrote 1 hour 8 min ago:
Most coal plants in the US aren't
ultrasupercritical. The first one only
went operational in 2013, in Arkansas
(the John W. Turk, Jr. Power Plant).
kragen wrote 40 min ago:
Oh, really? What temperatures do US
power plants operate their steam at?
mjevans wrote 1 day ago:
I'm going to want that pile hot enough to kill all the
bugs and pets that want to get near it.
pfdietz wrote 23 hours 46 min ago:
The surface will always be only slightly hot. Heat
will be stored inside, insulated by overlying dirt.
Dirt isn't the best insulator by thickness, but it's a
very good insulator by $.
jeffbee wrote 1 day ago:
I think they were referring to the fact that the chief reason
there is not large-scale PV panel recycling is that very few
panels have ever been retired. It turns out that short of
physical destruction by hail etc a PV panel does not degrade
beyond economic usefulness simply by being out in the sun. In
fact some panels actually get more powerful. The
surprising-to-some conclusion of NREL's PV Lifetime Project is
that the economic lifetime of a PV panel is basically forever.
jeffbee wrote 1 day ago:
There is one constant to all these conversations and that is Silicon
Valley tech dudes are grossly misinformed about the lifecycle of
things. Solar panels don't wear out, batteries don't wear out as fast
as they used to. This is evidenced both by undertaking weird dead-end
startup ideas, and being susceptible to propaganda about the supposed
downsides of solar energy and batteries.
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