I don't see much on this here. So, I thought I'd throw in my recent experience on research on it. I live in central TX (abundant sun). My house has a hip roof wth one quarter facing the south, detached garage, which is about 150 feet from house, has gable roof with one side facing south. Both are 5 on 12 pitch. My electric provider is PEC. http://www.pec.coop
My annual electric use has been approximately under 1100 KW for the past 3 years. I am the only occupant of the 1250 sq. ft. 3 bedroom home, completed in Feb 2005. The roof has composition shingles. The property consists of 5 acres in a rural area of course.
Here's an example of quotes for installation AFTER federal tax credits. Includes all hardware to connect between house main electrical panel and meter.
20 solar panels, 5000 KW/year, $16K
30 solar panels, 7500 KW/year, $22.6K
54 solar panels 13.543 KW/year $38.36K
In the latter case, some panels would have to go on the garage.
Complete battery system for off-grid, and/or, loss of electric from provider. $15K
Also, passive solar water heater
80 gallon tank, 2 roof mounted arrays, pump and electrical hardware. $5.6K
All are guaranteed for 5 years per their warranty. With the exception of the solar panels which is 20 years. Expected life for solar panels is 30-40 years. Battery life varies from 2-5 years depending on the type. Passive water heater uses a liquid that has to be changed every 2 years.
Some things that stand out other than the obvious money shock. Replacement of the composition shingles later for instance. PECs requirements, homeowners insurance coverage of both the hardware and potential for personnel death or injury from the equipment, and potential for damaging PECs equipment.
Okay, the company installs all the solar equipment. Now, I have to wait 60 days till they can connect it to the grid. Assuming I have the proper insurance of course. I still pay $22.50 a month for electrical service, even if I don't use it, or even feedback power to the grid in a net positive sense. And, I pay a hair more in electrical power usage from them if I connect this equipment to the grid.
I'm still waiting a response from my insurance agent on equipment coverage, and personnel and equipment damage liability regarding my current homeowners insurance. Some research shows that some homeowners insurance will cover such "green" things at minimal cost, some at greater cost, and some simply will not.
If I do decide to do this, I'll probably go with a the latter system with batteries. Build a big carport type structure to put all the solar panels on its roof, and battery storage area.
Financing, the VP at my local community bank isn't sure. Needs in writing from potential installation company their estimates of cost. She says I qualify for all that I listed as home improvement, but again, needs a hard paper cost from the potential installer. My home loan vs. house worth is definitely right-side up. (Not all banks will finance such "green" home improvements, right-side up or not).
There is much more detail to this. Hope this helps if someone is looking into this out there.