Sun strokes

摘要

So you want to offset your electricity bill by tapping the most widely available, free source of energy in the world, the sun? Right now, you'd need to shell out a lot of money for a specialist to come to your home and install inefficient solar panels on your roof. Now imagine taming the sun minus the specialist, the empty wallet and the panels. What if taking your home off the grid required only a trip to the shops, a bucket of paint, an afternoon on the roof with a brush and a couple of beers, and an electrician to hook your new roof up to your power supply? That's the promise of a spate of research into harnessing the sun's energy with materials called thermoelectrics, which can generate a current simply by exploiting a temperature difference between one side of the material and the other. Once written off as unusable, they might now find redemption by rescuing solar panels, which have hit a formidable pothole in their efficiency. Thermoelectric materials could help push them out of their trough and into the big league. But ironically the panels' saviours could also be the architects of their downfall.