Key Stage 3 (KS3) Energy Practice Test

Solar panels generate electricity primarily by converting sunlight into electricity using photovoltaic cells. These cells contain materials that exhibit the photovoltaic effect, where certain semiconductor materials, typically silicon-based, absorb photons from sunlight. When these photons hit the semiconductor, they provide energy to electrons, knocking them loose from their atoms. This movement of electrons creates an electric current, which can then be harnessed for power.

Photovoltaic cells are designed to maximize the absorption of sunlight, capturing and converting as much solar energy as possible into usable electrical energy. This process allows solar panels to provide a renewable source of energy, contributing significantly to sustainable power solutions.

The other options do not accurately describe the function of solar panels: harnessing wind energy pertains to wind turbines, converting heat into mechanical energy relates more to thermal power stations, and storing electricity for later use is a function of batteries, not solar panels directly.