Living Green: The Missing Manual

Solar Energy

That big ball of fire that rises in the east and sets in the west each day is a powerful energy source. And it beams its rays everywhere on Earth—for free. There are three main ways to harness the sun's energy:

• Photovoltaic (PV) cells. Explained in detail in the box on Geothermal heating and cooling, these cells convert sunlight directly into electricity. They can be small enough to recharge your cellphone or (combined into arrays of panels) large enough to produce energy for the national grid.

  

• Solar thermal collectors. Described on Going solar, these panels absorb heat from the sun during the day and release it as needed. They use the collected heat to warm up swimming pools, for example, or heat water that's sent through pipes to warm a building or even a whole neighborhood. The heat can also create steam that drives a generator to produce electricity.

• Solar dishes and other concentrating technologies. This category includes different kinds of high-temperature solar thermal collectors. A solar dish, for example, uses reflectors to collect solar energy and concentrate it into a single beam. The beam is focused onto a heat engine, which drives a generator to create electricity.

Advantages

Solar power has a lot going for it. Like wind energy, it's free, it's renewable, and it's ...