In spite of its low voltage, rooftop solar may actually be the deadliest source of energy! This is because the panels get dirty and need to be cleaned of dust, dirt, wet leaves, and bird droppings in order to maintain their efficiency. People will natu­rally climb up to the roof to clean their panels. Statistics on people falling off the roof and ladders are not readily available, but here are some figures for accidental deaths from falls. The Center for Disease Control and Prevention28 reports that 15,800 adults above age 64 died from unintentional falls. Another branch of CDC shows 19,195 total accidental deaths from falls in 2006.29 Data from the US Census in 2000 show that deaths from falls from one elevation to another were 3,269 in 1996.30 If we conservatively take the smallest number, about 3,000, and say that maybe 10% of those were falls from a roof or a ladder going to the roof, then 300 US deaths occur annually from such falls. Now if rooftop solar becomes wide­spread, this number may grow by an order of magnitude to 3,000 deaths per year. Compare this to the annual average of 32 coal-mining deaths in the USA from 1996 to 2009!31 Even the 4,000-6,000 coal-mining deaths in China is comparable to the number of USA fatalities if local solar power expands as intended.

Factories are usually large, single-story building with flat roofs. These would be ideal for solar installations. Forward-looking companies like Walmart and Google have already installed solar power on their roofs. Covered parking lots are also good candidates, and some are already being converted. These installations would be serviced by professionals, not homeowners. No doubt measures will be taken to make solar systems for homes safer. Panels can be designed with this in mind.32 Perhaps a cottage industry of panel cleaners will arise, the way chimney sweeps have been reinvented. Rooftop solar is needed, but its dangers must be minimized.