A high number of clear days with the sun shining bright is not enough (on its own) to make all types of solar power economical. Solar photovoltaic cells (called Solar PV) have a fairly high initial cost for installation in rooftop arrays, and debate dogs the question of a true payback period. The comparison with power costs from the local utility aren't always favorable, since electricity is best generated from solar power on sunny days (and defintely not at night). Storage batteries can help with the economics, but the efficiency of these schemes tends still to suffer in comparison. However, the debate on the economics of solar PV shifts when Climate Change is figured in the mix, and the potential costs of mitigation are considered.

Fox 11 News, Tucson AZ; June 30, 2008

Submitted by R. Campbell