Here's what he installed:
The 39 Kyocera polycrystalline PV (photovoltaic) panels have a total DC rating of about 8.2kW and are hooked up to a 7kW true sine AC inverter, arranged in 3 strings of 13. 2 of the 3 strings are on the side roof and 1 string (of 13) is on the front. Almost none is visible from the street.
Basically, I sized it for 80% of my power consumption and about 95% of my electric bill, giving me a little room/incentive to conserve further. So far, it is producing WAY more than what it's supposed to, and I hope it keeps it up. In March, it produced nearly 1200 kWh while, based on historical seasonal models, it should have produced only about 850 kWh. Woot!
Here is the production for yesterday, about 50 kWh total on a nice, clear spring day (click on picture to make it larger):
As the days get longer, it will be producing even more, but right now, it is producing much more than we are using, so it is going into the PG&E utility "bank" for winter.
For those in Seattle who don't pay 50 cents per kWh like I do, you can forget about solar panels. On a cash-flow basis, after taxes and payments, this is very "green" for me, saving me ~2/3 of my previous electric costs or about $200 of green per month. It's rather surprising how much energy falls from the sky where only a fraction of our roof is enough for all our electricity.
I spoke to my brother about the costs of installation and how long he thought it would take to pay off his solar panel investment. The top line cost for the panels was $48,000, but after $1.10 per watt credit from the state of CA and other federal credits and state rebates, he ended up paying only $28,000. He financed that through a home equity loan that he pays $85 a month on. Since he saves about $300 per month on electricity, it ends up being more like $215 savings a month.
At this rate it will take him less than 8 years to pay off the solar panels. And, after that point, it's free electricity. It's also possible that he could make money in the future since CA is in the process of figuring out how to compensate people generating electricity into the grid.
Not only is he saving money in the long-term, but he is substantially lowering his carbon footprint. According to the solar panel computer (which, by admission, is probably not extremely accurate), he saved 22,300 pounds of CO2 in March. That's the equivalent of burning 1,150 gallons of gasoline in an average car. For one month.
So, if you are thinking about going solar and you live in an area with high electricity rates and a lot of sun (and generous rebates), then get some solar panels already!