Solar thermal plants

A solar thermal plant. Notice how the mirrors reflect the sunlight onto a small area.
Source: Image courtesy of SHEC LABS

Just like solar cells, thermal plants trap and concentrate heat energy from the sun. However, they do so in a slightly different way.

These plants rely on the sun’s energy to heat a fluid into a gas to drive a turbine that generates electricity.

Some types of thermal plants use very large mirrors or reflective space dishes to concentrate the sun's heat on a single point, called a receiver. The receiver usually contains a liquid (such as highly concentrated salt water), which absorbs the solar energy. The liquid then gets turned into a gas, which then drives a turbine to generate electricity.

In France, there is a solar furnace that uses a huge array of mirrors to concentrate the sun's heat into a small area, producing extremely high temperatures up to 33,000 degrees centigrade.

In Australia the CSIRO is developing a system that traps solar energy in a dish and uses it in a methane enrichment plant to produce more efficient energy and reduce greenhouse gas.

Learn more about CSIRO’s solar dish .