PowerSource

Thermoelectric coolers are a neat (although potentially energy-expensive way) to cool devices such as solid-state lasers and even high-performance processor chips. This current Design Idea,  Use thermoelectric coolers with real-world heat sinks, by the popular Design Idea author Stephen Woodward, gives some circuit design tips for real-word designs (read: non-ideal heatsink characteristics.)

A recent Science News looked at research involving the other side of the thermoelectric effect: Thermoelectric materials exposed to heat differentials will generate voltages. Researchers at MIT took the alloy bismuth antimony telluride and by grinding up the material and re-compressing were able to increase the material's thermoelectric effect by 15-30% - a sizable increase. This discovery could result in a new kind of solar panel that harnesses the difference in temperature between the panel's hot, sunny side and its cool, shaded side for a solar panel efficiency of 5 to 7 percent — true, less efficient than traditional photovoltaics, but potentially at a lower cost per watt.

UPDATE: Researcher Prof. Gang Chen of MIT asked that I add Boston University and GMZ Energy in addition to MIT, since this is a joint work.