Craig Perkins is a bike geek who works for the Department of Energy's National Renewable Energy Laboratory in Golden, Colorado. His "group performs applied research involving the surfaces and interfaces relevant to next-generation thin film photovoltaic technology."
Put the two together and what do you get? Dreams of solar-powered scooters!
An excerpt from his most recent blog post:
On a clear day you have about 1000 watts per square meter of [sunlight]t bearing down on you. It is a testament to the efficiency of the bicycle that it is entirely possible that some day, just the sunlight hitting your body could provide the power to scoot around on two wheels. Skeptical? An in-shape cyclist might produce a few hundred watts of power for a short length of time. Let's assume that us normal folks produce about half of that, about 150 watts. If we take the area of the typical human shadow to be 0.7 square meters, then we have about 700 watts of light hitting you and your clothing on a clear day. How much of that light energy might we capture, and how? Some of my fellow geeks are actually working on integrating thin film photovoltaics with clothing and other textile products. Let's assume they are successful. The current world record efficiency for thin film photovoltaics stands at right around 20 percent. Putting those numbers together yields an estimate of 140 watts of harvestable photovoltaic power, a level very comparable to the energy cost of cycling.
All of those people out there who think Lycra-clad cyclists are a fashion monstrosity? Just wait until that Lycra incorporates thin film photovoltaic technology! Then we'll talking some serious threads.