End to All Power Problems

Magfan - to get some feel for the size and the cost I looked at Yingli Green 235P-29b poly-silicon solar panel. It delivers 235W and costs $550. Size wise it is 40"x65". 10 panels would be plenty for my energy usage returning power to grid most of the time except when air conditioner or heater would operate. Assuming 5hr of partial sunshine a day would make 1kWh per panel per day. 15 panels = 15kWh a day would make 450kWh per month - your energy needs. It would cost $8250 - one time expense with possible gov. rebates. There would be installation cost, inverters etc. so I'm not really sure what would be the total. Let assume total would be $10k. Assuming about $0.1 per 1kWh it would return investment in 18.5 years - too long. Statistics showed 7.5 years return but it could be in the best scenario with gov. rebates and quantity discounts. On the other hand it is 25 years of clean energy.

As near as I can 'figger' the best practice today is having a small inverter at EACH panel. Then you worry about AC from then after without the losses associated with DC.
Sync of inverter frequency may be an issue?

Your reference panel is about 2600 sq inches or over 18 sq feet....this is 2 square yards and quite in line with my 'rule of thumb' of 100 watts per square yard.

Polysilicon is MUCH less expensive than single crystal. In my application, when I need it most is summer when the AC kicks in most. I would love to see the 'derate' of this panel and see what it'll do in 90f weather. I also, in the summer, can count on somewhat more than 5 hours per day. I'd have to consult an 'expert' with all the local data for better than 'guess' numbers.
Now, assume I use 15kwh per day. I'd need to get most of that back in say.....8 hours in summer so I'd need nearly 2000 watts of panel, counting the derate. Maybe those 10 panels would get me there....maybe not. Winter would be another story and I may be able to count on only 5 or 6 hours, plus the inevitable 'weather loss'. So, to deliver 450 kwh in a month 'worst case', I'd need a few more panels. Maybe more than a few......I'll have to sit down and run some more serious numbers.
Point is, if I plan for worst case....that being the least amount of sun, I'll need more panels than run a surplus during the summer. That may be best, but not necessarily for me.
One PLUS for me is that one big flat side of my roof faces south and west. The MINUS is that I have a large slope in back. The sun sets on the highest part of the slope in winter and the lowest part in summer.....and since the sun 'moves' its point of set, is always in between those 2 points.

If I could go 'all in' for any less than 15,000$ I'd be surprised. Even if I got back say.......5,000$ in kickbacks, tax breaks and incentives, I'd still have to figure out how long it'd take me to use that much electricity. 100$ per month for 100 months....that's a tick over 8 years.....Better than I thought, but I'd still like to see some real numbers.
Maybe I could afford that class 'a' Pass amp, after all!

I'm also going to call SDGE next Monday, and spin a story. I'll tell 'em I've got one of there electronic meters and intend to go solar. The 'new' meter won't go backwards so It's either cut me a fixed benefit deal or give me my old meter back. Just to shake the tree, you understand.

Magfan, you need to check with someone at one of the non-profit "green" coalition about the meter issue. I'm not an advocate for gov't subsidized anything, but, it's seems at odds the the gov't is subsidizing these technologies, then the state commisions allowing the utilities to screw you on the rules.

There must be a group working on a class action suit against the utility. It should only have to go the state commision,and that can actually get resolution, in many states, very quickly.

Good luck.

I'd be just checking with the power company. I'm not going to go solar, but I'm just curious what they'll say. The push is on in Southern California for 'smart' metering. This is a prelude to charging differential rates based on time of day.
Name something the government doesn't have there hand in?
As a matter of 'public policy' and wanting 'green' I'm afraid that tax money will go to those changing over to solar and maybe even other technologies. Aren't there even some subsidies for certain 'green' cars?

Magfan,

2500W inverter is about $1700. I found LDK panels to be a little cheaper $500 for 235W.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250721031603&hlp=false&rvr_id=175661700227&crlp=1_263602_304652&UA=M*F%3F&GUID=6b8fbb1f12b0a0aad3009e10ff5125d6&itemid=250721031603&ff4=263602_304652

Specification at the bottom of the page show 0.47%/degC temperature coefficient of max power with nominal air temperature of 20deg C. If higher temperatures cause loss of power then 20degC increase will cause 10% loss.
It is guaranteed to deliver 80% of nominal output after 25 years. Your meter situation is a serious drawback since largest loads (air conditioning, heating) should partially operate from the grid while during rest of the time energy should be returned to grid to get overall balance better than zero. Power companies sell energy and need people to be dependent. They won't make it easier for the people to install solar panels unless courts will force them to.

Small solar panel can run small water pump that irrigates small field - it means food for some people for the next 25 years.