With so many soldiers being deployed in hot sunny places, it seems like a no-brainer to put all that blazing sunlight to good use. So a British team has developed a special photovoltaic fabric, that captures the sun's rays to provide juice for all of a field soldier's electronic gadgets.

To build a solar power plant, you need two things: lots of energy, and lots of silicon. The Sahara desert can provide scads of both, and by using power plants to 'breed' more power plants, the Sahara Solar Breeder Project will theoretically be producing enough green energy to power half of humanity by 2050.

How does a nuclear reactor work? This cutaway diagram of the No. 32 Windscale AGR reactor in Sellafield, U.K., gives a few clues.

Go ahead, turn up the heat. Alphabet Energy can take it and then use it to reduce your power consumption. The firm wants to harvest wasted energy found in the heat given off by mechanical and electrical processes, using thermoelectric...