PV Gap

Douglas Said:

Are there any ROI studies regarding concentrators and tracking systems for solar cells (PV)?

We Answered:

You might want to check out this website.

It will cost you a pretty penny to have one installed. Make sure your home roof is designed for it.

Good luck.

Elizabeth Said:

What will it take to get US residents to adobt more solar PV systems on rooftops?

We Answered:

More economic incentives

Minnie Said:

Do you think all Grid tied Solar PV systems sell back to the grid?

We Answered:

I do not agree at all. I live in Phoenix which is one of the few ideal locations for solar. A system for my house will break even in 11-13 years, but only getting almost half of it paid for by the taxpayers and Utility rebates. If the system had to stand on its own, it would never break even. Also the break even does not include any maintenance and replacement costs which is inevitable. In most areas, these systems will not do as well as here.

Tax dollars are not FREE. It is hard-earned money by millions of hard-working individuals. Most of us do not have $20,000 laying around to install a system. Only the rich do. Using my tax dollars to help the better off to justify or sell a money losing Solar system is WRONG!

Let the market work! Don't use my money to prop up these systems. Build Nuclear Power, or help people that really need it if you want to spend my money. Again - Tax Subsidies are not FREE.

Velma Said:

What is the feasibility of a Solar PV system with Heat Pump in the SF Bay area?

We Answered:

I live in Martinez and have a 6 kW system in a house of about 2200 sq ft. I live alone, and am quite frugal with heating and air conditioning. I heat water with gas.

I am able to zero out at the end of the year, having generated just about as much as I use.

If your roof is pitched and the ridge line runs close to east and west, and with a 6kw system, you should be able to generate as much as I do. My system is shut down tonight, but tomorrow I will take a reading and amend this response with the average annual output. This will give you an idea of what to expect.

As to the heat pump, I just don't know. If I were to replace my furnace and AC, I would get a heat pump. Unless someone convinced me it was not worthwhile, I would have the return line extended for a considerable distance underground. Not a true ground source system, but to do some precooling or heating to assist the heat pump.

Sunday AM
Over the past four years my system has generated an average of 5,100 kilowatt hours per year.

One more thing. I have nothing shading my system in the summertime, and only a bit of shading in winter. If you have trees or other things that will shade your system, all bets are off..
And one more thing. Not everyone can do it, but my modules are just over the garage and a large overhang. I didn't want them over the attic, fearing roof leaks some day. I have had one small leak in the garage, and was so happy I did it that way. If the modules had to be over the attic, I would have had the installer mount them higher above the roof than they usually do, with the mounts easily accessible. That way one could recaulk them periodically, and/or if there were a leak.