Photovoltaic (PV) solar is the dominant technology in the solar power field. It turns sunlight into electricity through one or more solar collectors connected to an inverter. The inverter transforms the collected direct current (DC) energy to alternating current (AC) electricity to power electrical devices. Storage batteries are often included in a PV system to provide energy back-up or low-sun power in remote installations.
Solar thermal systems capture the thermal energy of the sun collected by solar panels to heat water for hot water tanks and pools. Solar thermal hot water systems contain one or two well-insulated storage tanks and one or more solar collectors. Systems deemed "active" include circulating pumps and controls, while systems that do not contain those items are called passive. In two-tank systems, the solar water heater preheats water before it enters the home’s primary water heater. In one-tank systems, the primary water heater is combined with the solar storage in one large tank. Solar thermal pool heating systems have a solar collector connected to the pool's existing cleaning filter and pump. The pool water is pumped through the filter to the solar panels, where it is heated by the sun and pumped back to the pool.
Concentrated solar utilizes reflectors to concentrate a large amount of sunlight onto a small collector surface to store heat energy. The applications of this technology range from small solar cookers for eco-friendly food preparation to vast fields of utility-scale mirrors for large-scale industrial energy projects.