Concentrated Solar Power

What Is It?

Concentrated solar power (CSP) focuses sunlight onto a small area and uses the resulting heat to make electricity. Mirrors or lenses concentrate the scattered light from the Sun into a focal point, heating up a fluid by hundreds of degrees. The heat is used to make steam, which moves a turbine and generates electrical power.

Why Does It Matter?

Sunlight is the Earth's most abundant energy resource, but it disperses so much that little energy is available at any given spot. By focusing the Sun's light onto a focused area using parabolic troughs, dishes, or even huge towers, the energy is concentrated and used more effectively to make electricity.

One of the drawbacks of CSP is the large amount of space that is needed to collect a useful amount of solar energy. But in places such as deserts with open, sunny spaces, concentrating solar technologies can generate utility-scale power at relatively low cost.

What's Next?

Because the Sun's energy is intermittent, maximum sunlight can be captured for only a few hours each day even in the sunniest locations. Some of the newest installations use molten salt that can store heat for hours or even days, allowing solar power plants to continue generating electricity during the night or during times of cloudy weather.

Real-world Examples

The PS10 Solar Power Plant collects solar energy in southern Spain. Photo courtesy of Flickr user afloresm.

The Solana project near Phoenix, Arizona, will produce 250 megawatts of power with a molten salt thermal storage system.