An easy way to determine how much solar you need is pretty simple. Get a electric bill and see your yearly average usage. If you use 800 kW per month; just divide that number by 30 days. In this situation; this house uses 26 kwh per day. There is on average 5 total hours of good sun; so dividing the daily usage by 5 hours; requires a 5.2 kW or 5,200 watt system. If you buy from a vendor like this; just use the hardware cost and factor 4 panels = 1,000 watts. So if this person needs 5,200 watts system; they need 21 panels, an 6,000 watt invert or and roughly 2k in labor to install. That will give you the amount to energy. And if you look at how much a kilowatt hour costs; you can multiply your average by the average kWh cost of .22 cents.
I really never thought much about solar... but then I read this today: http://grist.org/climate-energy/sol...tm_medium=web&utm_campaign=outbrain-gristiest Now this has me reconsidering. In summary, as more and more people move to solar, the rates for everyone else will go higher... causing more and more people to move to solar. Perhaps this is true, perhaps the utilities are just trying to protect their turf, but it seems pretty logical.
That's why I recommend power one converters. They can actually carry a start load of a fridge or high amp appliance. Add battery (enough to give full daily watt usage at 50%) and it will give you even a better load. Many people that buy into "off grid" systems should absolutely jump on power one inverters.
It doesn't work that way. You have to exchange excess power you make during the 5 good hours of sunshine with the power company / utility to get power during the other 19 hours. If anything, the power companies are being raped by requirements they overpay for the electricity people with solar put back on the grid. Truly "Off Grid" means you need to store electricity you generate in batteries to use during those other 19 hours. Expensive and they don't last a long time.
I don't see how solar would put utilites out of business. If I have a net positive electric use I pay over 7 cents/kWhr. If I have a net negative electric use, they pay me 2 cents/kWhr. Not to mention there are $20+ charges each month for the priviledge of using the grid.
In SoCal (SCE), the monthly charge is $1.98. And if you generate more power; they pay 0.115 a kWh. The charge per kWh ranges from .18-.38 per kWh.
Weird, here's what everyone else pays: http://www.npr.org/blogs/money/2011/10/27/141766341/the-price-of-electricity-in-your-state
I'm just going on what SCE's website has. And right now; that's our rate. According to the nem program; they buy back energy at the rate you pay. I think this is how they are losing money. They aren't making money on the solar energy they are buying back.