Renewable Energy From the Sun
Energy from the sun is renewable, meaning it never runs out. Unlike fossil fuels, it does not create pollution that harms the environment and human health. Humans have been using solar energy for more than two millennia, beginning with the use of glass lenses to focus sunlight and make fire. In 1839, a French physicist named Alexandre-Edmond Becquerel discovered the photovoltaic effect at the age of 19. Photovoltaic cells Solar cells convert sunlight into electricity by using semiconductor material to absorb photons of light and release electrons. The absorbed electrons then flow through the cell and out of its conductive metal contacts, generating an electric current that can be used to power equipment. Silicon is the most common semiconductor material for PV cells, but other materials like amorphous silicon (a-Si), cadmium telluride (CdTe), and copper indium gallium selenide (CIGS) can also be used. The cells can be either brittle crystalline structures, or flexible...