Green Science Image Gallery
Green Science Image Gallery

Solar-thermal collectors are able to keep the plant running after the sun has gone down. See more green science pictures.

Image courtesy of EIA/NREL

If you've ever bought carbon offsets, you may have noticed that the most or all of the purchase price goes toward wind energy, not solar. In the world of large-scale alternative energy, wind reigns supreme, mostly because it's cheaper. But a recent development in solar-energy production could make solar power a far more viable option.

In most cases, the sun's energy is converted into electricity in one of two ways: using photovoltaic cells, which turn the sun's light into electricity using a semiconductor material that absorbs photons and releases electrons; or using solar-thermal turbines, which use the sun's heat to generate steam, which then spins a turbine to produce electricity. It's the solar-thermal power plant that is poised for a big change.

The big problem with solar power is the most obvious one: The sun doesn't shine all the time. At nighttime or on cloudy days, power plants simply can't access the sun's energy. This makes solar power expensive, since the power plants can't run 24/7. A cloud floats overhead and the plant is suddenly at an energy standstill, producing nothing. It also makes solar-generated power unavailable at times -- like at night, when power demand is greatest.

The solution is a simple one: Store the sun's energy so you can use it when the sun's not available. Unfortunately, implementing that solution has been extremely problematic -- until a recent breakthrough made solar-energy storage a realistic option for the energy industry.

In this article, we'll find out how it's possible to efficiently store the power in sunshine so we can access it when the sun sets. We'll also look at the first commercial power plant built to use the technology to find out how the system works.

The storage material that makes the breakthrough possible is probably sitting in your kitchen right now.