Most people know that solar power is the power that is generated from the heat and light of the sun. However, many people are not exactly certain how this type of energy works. It is easy to say that we use the sun’s power to create energy--but how does solar energy work? How is the light and heat of the sun harnessed and then converted into electricity?
Most solar power systems use photovoltaic (PV) technology. Scientists actually call solar cells photovoltaic cells. This term is used because the cells convert light--or photons--into electricity--or voltage. Photons + voltage = photovoltaic. The process of converting the cells is called the PV effect.
Solar energy systems typically use solar panels that are comprised of dozens of solar cells (or PV cells). These panels are often called photovoltaic panels, and a typical home likely needs about 10 to 20 panels in order to provide enough energy to fully power the entire home. The solar panels are mounted at fixed angles facing the south, or they may be fitted onto tracking devices that follow the sun as it travels in the sky; either of these options allows the panels to capture the most sunlight possible. If many panels are affixed together in one system, it is called a solar array.
Traditional solar cells that are used in PV panels are usually made from silicon. These are typically flat-plate and are the most efficient type of cells. Second-generation cells (also called thin-film solar cells) which can double as rooftop shingles, tiles, and building facades are not made of this material. Instead, they are made from amorphous silicon or non-silicon materials such as cadmium telluride. Some experimentation is being done with new materials for solar cells, including using solar inks, solar dyes, and conductive plastics.
Power plants do not use photovoltaic panels in order to capture solar energy. Instead, they concentrate solar power through the use of linear concentrator systems that use U-shaped mirrors. These mirrors are tilted toward the sun and cause the collected sunlight to focus on tubes that are filled with a fluid. This fluid is then used to boil water in conventional steam-turbine generators in order to produce electricity.
Some homes and businesses also use solar energy for water heating systems. These are used as alternatives to traditional hot water tanks. Solar water systems have two parts--a solar collector and a storage tank. The solar collector is typically mounted on the roof of the home or business; it is a thin and flat rectangular box that resembles a photovoltaic panel. Small tubes run through the collector, however, carrying the fluid that is to be heated. As the fluid is heated, it passes through the tubes and is sent to the storage tank for holding.
Solar energy is continually being studied, so new technologies and methods for harnessing and converting the sun’s power are likely to be discovered. Because of this guide, though, ‘How does solar energy work?’ will no longer be a question for which you need an answer.
Some homes and businesses also use solar energy for water heating systems. These are used as alternatives to traditional hot water tanks.