Solar panels capture energy from light and convert it to electricity. This is the most visible form of energy harvesting, but it is hardly the only one. Energy harvesting captures energy lost as heat, light, sound, vibration, or movement. Devices that harvest or scavenge energy can capture, accumulate, store, condition, and manage this energy into electricity for consumption. That’s important, because our existing electricity infrastructure is extremely wasteful in its use of energy. For instance, today’s technologies used in electricity generation are not energy efficient. Traditional gas or steam-powered turbines convert heat to mechanical energy, which is then converted to electricity. Up to two thirds of that energy input is lost as heat. Those old incandescent bulbs (technology invented by Thomas Edison in 1879) were real energy losers too. Ninety percent of the electricity flowing into incandescent bulbs ends up as waste heat. That’s lost energy, which is why smart federal legislation banned incandescents in favor of more energy efficient sources of lighting starting in 2012.
