Key Stage 3 (KS3) Energy Practice Test

Geothermal energy is best described by the statement that highlights the process of using heat produced from within the Earth itself. This energy source arises from the natural heat stored beneath the Earth's surface. In particular, the hot rocks in the Earth heat underground water, which can then turn into steam. This steam can be harnessed to drive turbines that generate electricity.

The other statements refer to different forms of energy: The first option pertains to solar energy that harnesses heat from the sun, while the third describes wind energy that relies on the kinetic energy of moving air. The fourth option relates to wave energy, which captures energy generated by the movement of ocean waves. Each of these describes distinct renewable energy sources that are not related to geothermal processes, thereby reinforcing why hot rocks heating water is the defining characteristic of geothermal energy.