A wind turbine is a machine that changes the movement energy of wind into electricity. In 2024, hundreds of thousands of large wind turbines, grouped in areas called wind farms, produced over 1,136 gigawatts of power. Each year, an additional 117 gigawatts of power were added.
Wind power uses wind energy to create energy that can be used for work. In the past, wind power was used with sails, windmills, and windpumps, but today it is mainly used to make electricity. This text focuses only on wind power for electricity.
Solar power, also called solar electricity, is the process of changing sunlight into electricity. This can happen directly through photovoltaics (PV), which use solar panels, or indirectly through concentrated solar power (CSP), which uses mirrors or lenses to focus sunlight. Solar panels use the photovoltaic effect to turn light into electricity.
Energy storage is the process of saving energy created at one time to be used later. This helps balance when energy is needed and when it is produced. A device that stores energy is often called a battery or accumulator.
Net metering, also called net energy metering (NEM), is a system used to measure and bill electricity for homes or businesses that produce some or all of their own electricity. This system lets users use the electricity they generate at any time, not just when it is made. This is especially helpful for renewable energy sources like wind and solar, which do not always produce electricity when needed.
A solar panel is a device that changes sunlight into electricity using several solar modules made up of photovoltaic (PV) cells. PV cells are made from materials that create excited electrons when sunlight hits them. These electrons move through a circuit and produce direct current electricity, which can power devices or be stored in batteries.
A rooftop solar power system, also called a rooftop PV system, is a type of solar energy system that uses solar panels placed on the roof of a home or building to generate electricity. These systems include parts like solar panels, mounting structures, wires, inverters, battery storage, controllers, monitoring tools, energy management systems, net metering equipment, switches, grounding tools, protective devices, combiner boxes, weatherproof enclosures, and other electrical parts. Rooftop solar systems are smaller than large solar power plants that are built on the ground and can produce millions of watts of electricity.
Solar thermal energy (STE) is a type of energy and a method for capturing sunlight to create heat. This heat is used in industries, homes, and businesses. The United States Energy Information Administration divides solar thermal collectors into three groups: low-, medium-, and high-temperature collectors.
Concentrated solar power (CSP), also called concentrating solar power or concentrated solar thermal, uses systems that gather sunlight to create heat. This heat can be used for tasks such as cooking, removing salt from seawater (desalination), or generating electricity. Mirrors are used to focus sunlight from a large area onto a receiver.
Photovoltaics, or PV, is a way to change sunlight into electricity using special materials that react to light. This process, called the photovoltaic effect, is studied in science fields like physics and chemistry. It is used in products that create electricity and in devices that detect light.