In our never-ending quest to popularize waste heat as a new energy source comes this bit of news:
Finland's Helsingen Energia plans to build a data center underneath a cathedral and capture and channel the waste heat into the municipal heating system. Although the data center will be relatively efficient, it will still generate about the same about of energy in the form of waste heat as a wind turbine. The heat effectively gets sucked into water pipes, which snake through homes around Helsinki. Waste heat isn't free – you have to install equipment to capture it – but it's relatively constant. The sun goes down, but computers never stop (except, of course, in an Omega Man-like future).
You probably don't know it, but you live in the dawn of the Golden Age for waste-heat research. The U.S. consumes around 100 quads (100 quadrillion BTUs) of energy a year and 55 to 60 quads get dissipated as waste heat, according to Arun Majumdar, the UC Berkeley professor who now runs ARPA-E, the advanced projects group inside the Department of Energy. Besides, you've already paid for it. Quite simply, it's power delivered but not exploited for a productive purpose. A variety of startups in the U.S. will soon release products that will more efficiently capture and convert heat or allow notebooks to run longer. You can read about a whole mess of them here.