I presume TVA is getting grant bucks to go "green." TVA does not have net metering contracts in place with the utilities, so connecting solar under their program requires installation of a second meter. I would be buying all household electricity from the utility for retail rate (9 cents/kwh), but TVA/utility would be buying ALL solar power I generate at 12 cents over retail via the second meter($0.21/kwh, currently). This is a substantial gain over net metering. TVA agrees to this rate plan for 10 years after the solar system is put into operation.
If I were faced with net metering, this would be a dud from the get-go.
A 10kw system would make around 12000 kwh per year, according to the calculator at IMBY,
http://www.nrel.gov/eis/imby/ which seems more conservative that other estimates I've seen. Net yearly income from selling power, 12000 kwh x $0.21/kwh = $2520.
Still struggling with how to evaluate the investment. Do I consider only payback time? Return on investment? Depreciate the system cost over how many years?
jurgen