Subj : good info 2 share To : All From : Skuz Date : Thu Jun 01 2017 22:57:16 Msg : 121 of 121 Rcv Pvt Loc From : White-Knight-32-KS 01 Jun 17 22:39:45 To : Skuz Subj : more solar =============================================================================== Hiya Skuz, When I took care of Dad, I was rarely home much, other than maybe 4 to 6 hrs, for 4 days/week, so I had minimal usage & bill was for abt 49 to 53 KW.Hr/month. Boiling those numbers down, I could run my place on a cheesy 200 watt inverter, for 3 flourescents and 4 alarm clocks! But my usage has doubled, since then & I need to expand by 4, instead of 2x panels. I haven't bought batteries yet, still looking over local options yet, no freight weught that way! I'm working on 12Vdc to 120Vac system, which means, I still pay for any 240 Vac appliance use, like window a/c! That's fine, for general survival & backup from storms. If you have to have a 240 Vac inverter output, then you must go either 24 or 48, or even higher inverter/battery system. I can't justify the expense of 48Vdc systems, the efficiency isn't there, for me. So, that leaves 24 Vdc inverter/battery systems, that means double the panels & batteries, of a 12 Vdc system! So, be braced for that expense! That's just one of those things that folks just have to decide for themselves, 12 or 24 volt systems, and what determines that is the need for 240 Vac. Now, this area, at my location, the worst time of year for short daylight hour days, is usually Dec, anywhere you go, but here, it's 4.7 or 4.8 hr days. I use that to figure my DC generation rate, of X KW/day, I look at summertime as bonus hours, nothing more. And figure from there. The avg. solar declination is 37 degrees, if I'm thinking right, the angle from horizontal, southwards, to the sun. Add another 90 degrees over the top, northwards, and that will be the angle of your tip axis, if you go single axis tracking. For major cities, none near here, but I avg'd out OK City & KS City weather, for number of cloudy days/month & rainy days, just for rough payoff figures, which is what you are going to need to convince any banker & general info. That is also how I got decent solar hrs/day, for each month. You can figure yearly cost/savings fairly accurately, that way. I made up a chart for this area, off of that NWS data. My goal is 12 Vdc @ 40 Amps, for that 4.7 Hr day. 12 x 40 = 480 watts/hr. 480 watts x 4.7 hrs = 2256 watts/day = 2.256 KW/day. Simple enough, that's my planned generation rate, to break even. That is also = 15.792 KW/week = 67,116 KW/month (4.25 week/month), not too shabby and covers my usage fairly well. Now, batteries! Here's a rating standard, that you likely not see on batteries, except on small electronics. Amp/Hr rating is simple, best example is like cell phone recharger battery packs (I'm using my own in this example). 10,000mA = 10A, not too big of conversion, just move decimal 3 places, from milliamps to amps. Now, my cell phone battery is about 2 Amp/Hr, which means I can put a 1 amp load on it for 2 hrs, no more. Using this 10 Amp/Hr charging pack, to recharge it, means I get 5 complete recharges, before I need to poop up the charger pack again! Just Amps per Hour, dividing math. You are always going to get rainy/cloudy/snowy days, figure those days into your battery array charging time, back to the NWS weather data, for your area! You can use normal car batteries for small projects, but not ideal for a home! Commercial Marine Deep Cycle batteries are better suited for hard draw & long time draw. This is under more thought, at the momment, as I'm still collecting panels! White-Knight-32-KS aka KA0YCU --- Mystic BBS v1.12 A33 (Windows/32) * Origin: flupH | fluph.darktech.org (9:91/1) .