Tower of Power

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Sunlight is a powerful thing. A tiny magnifying glass is able to focus just a little bit of the Sun’s light into a hot beam. This beam is hot enough to burn a small pile of dry leaves!

Do not try this without adult supervision!

Imagine how hot it would be if an entire field’s worth of sunlight were focused onto one tiny point.

You would get a superhot beam of bright light. Sounds like something out of science fiction, right?

But it is not science fiction at all. In fact, this beam of light is the key ingredient in the newest form of solar energy. This technology is named concentrating solar power, or solar thermal energy.

A solar power tower surrounded by mirrors.

A sea of mirrors directs a powerful beam of light toward a solar power tower. Credit: GreenMPs

The basic idea is simple. The Sun’s light is focused onto a small area using mirrors. The mirrors constantly follow the Sun as it moves through the sky. They do this to make sure they are receiving as much light as possible.

The beam created by all of these reflecting mirrors is used to heat a liquid to an extremely hot temperature—sometimes over 1000°F! This liquid is a chemical that is very good at trapping heat. After it is heated, the liquid is pumped through a tank of water in a pipe. These hot pipes cause the water to boil and create steam. This steam spins a turbine, which powers a generator. Sometimes, the hot liquid itself is used to power the generator.

That’s how this technology gets electricity from the Sun!

Solar concentrating power is important because it produces energy without releasing harmful greenhouse gases into the atmosphere. It is also great because we are in no danger of running out of sunlight!

In fact, all of the energy that the ocean, land, and air absorb from the Sun in just 1.5 hours could power the whole Earth for an entire year!

Many countries, including the United States, are beginning to adopt concentrating solar power. The technology is only getting better. This new kind of solar energy could be very good news for our planet.