Everyone has heard the pitch for solar energy, install solar cells on your roof and get free electricity from the sun. Sure they cost a lot up front, but they will last 25-30 years—which just happens to be about the payback time given current electricity rates from coal, nuclear and natural gas. However, if the panels produce less than their promised power or start failing in two or three years, or are unusable or unsafe, the economics of solar power collapses.
