I’ll try to answer the ones that aren’t model/manufacturer specific.

7-8) It can very from 12, 24, 48, 96 volts and some installations use voltages in the 100s of volts. Higher voltages allow the use of smaller gauge wire. If you start with 12 volt panels then you wire them in series to get a higher voltage.

9) Inverters are pretty efficient. I think most are around 98% these days.

11) Check the utility site. It varies.

14) We don’t know. The oldest installed solar panels are now about 40 years old and are producing about 80% as much power as when new. A 0.5% (or less) output loss per year is reported from several sources.

A 30 year study of a large array of panels found the 0.5% loss and during the 30 years about 2% of panels failed due to delaminating and connector failure. My guess is that over that 30 years we’ve learned how to build panels better so the 2% loss might not be repeated.

That said, there have been some manufacturers who have produced some inferior panels. There are now a couple of independent agencies that certify quality.

The other questions, you’re going to have to look at specs. Here’s a site that has excellent prices and a good reputation. (Do your own due diligence.)

http://sunelec.com/

Here’s a company with whom I’ve done a fair amount of business and they’ve treated me well.

http://www.backwoodssolar.com/

QUESTIONS:

(1) What is the solar collection dimensions of each individual panel, length by width?

(2) What is the DC output power of each individual panel, in watts (clear sky, sun directly overhead [on normal to panel])?

(3) What is the matching impedance (in ohms) to collect the maximum DC output power of an individual panel?

(4) What is the DC output of an individual panel into its matched impedance, in volts and milliamps (clear sky, sun directly overhead [on normal to panel])?

(5) Does the solar panel power output degrade with high ambient air temperatue (ie: in hot weather)? If so, how much?

(6) How does the DC output power, voltage, and current vary for a solar angle off of the normal to an individual solar panel (clear sky, value vs. angle 0 to 90 degrees)? Does the optimum matching impedance vary with the off of normal angle?

(7) What is the nominal DC input voltage to your AC power converter (inverter)?

(8) Is more than one panel in series necessary to provide the DC input to your AC power converter? If so, how many?

(9) What percent of the DC output power of the solar panels is transferred into 60 cycle 240 VAC single phase power by your converter?

(10) When the sun is down (at night) does your power converter use any AC power to keep it in “stand by” mode? If so, how much?

(11) When the “meter runs backwards”, how does the power company (Southern California Edison) “credit” the customer for this power? Is the power company required by law to provide this “credit”, or is it voluntary (and therefore revocable by them in the future)?

(12) What is the cost of an individual solar panel (un-installed, still in packaging)?

(13) What is the cost of your DC to AC converter (un-installed, still in packaging)?

(14) What is the expected life span of a solar panel, in years?

(15) What is the expected life span of your DC to AC power converter, in years?

(16) What is the warranty on your solar panel? Does the warranty cover weather damage (hail, sleet, wind, sand storms, sub. freezing temps., ice damage, etc.)?

(17) What is the warranty on your DC to AC power converter?

Jim (e-mail: shortysears@gmail.com)