Solar energy works based on the photovoltaic effect. Simply put, when sunlight hits a solar PV panel, its photons (particles of light) are absorbed by the semiconductor material in the panel. These photons excite the electrons in the semiconductor material, causing them to be released from their atoms. These released electrons form an electric current inside the material, which in turn generates electricity. This process requires no fuel and relies entirely on sunlight as a source of energy, making solar energy a clean, renewable source of energy.