# billybob

Member Since: December 30, 2006

Country: United States

• Does it make (economic) sense to install a solar power system?
Considering the real installation cost of about \$40,000, If you put the \$40K in a 10 percent investment program (they're out there) the uncompounded simple monthly interest would pay \$333.33 toward your electric bill and require no maintenance, no space in your back yard or roof. The income would be perpetual.

• How do we store energy for night time use? How much energy do we need to store? Answer: If we consume 100A for a period of 4 hours, that works out to 400 Amp-Hours. To supply 400 Amp-Hours at 50 pct load current and 50 percent discharge, about 16 100 Amp-hour storage batteries are needed. This is an added cost of about \$2000. We may expect the batteries will be replaced every 2-3 yrs. Power conversion here assumes 100% efficiency too. Battery cost over 20 yrs could be \$20K.

• Typical 60W panels run \$300 each. A 4000W array of panels would require 67 panels x \$300 = \$20,100 for the panels. Have you included the cost of mounting frames, positioners, position controllers, charge control for DC storage, DC storage batteries, and power inverters for power conversion to AC?

No public wish lists :(