Solar power is a clean, reliable form of renewable energy generated by converting energy from the sun's radiation into electricity. Solar cells, also referred to as photovoltaic cells (photo = light, voltaic = electricity), are grouped and connected together in a single frame called a panel or module. These cells are comprised of special semi-conductive materials, which is most often a piece of silicon positioned under a layer of thin glass.
During the day, rays of sunlight shine on each of these photovoltaic cells. The silicon in each cell absorbs a portion of the sun's energy and releases particles, called electrons, in the semiconductor, enabling them to flow freely. The electrons flow in a particular direction, based on one or more electric fields contained in the solar cells.
Small wires run along the top and bottom of each solar cell and harness these electrons to form an electric current when connected in a circuit. The current can then be stored as energy in batteries and/or passed through an inverter that converts the electricity to the type of power used to run appliances and other electronics, such as many of the items found in the average home. The current, in combination with each cell's voltage, defines the power output (Watts) the photovoltaic cells can produce.
Photovoltaic cell technology has progressed significantly in recent years. Cost reductions, improved energy efficiency (the ability of the cells to transform sunlight into usable energy) and higher production rates mean solar power is now available for an increasing number of applications - from solar calculators to large solar power stations.
What is Grid-Tie Solar Power?
The process of synchronizing the energy output from a solar power system with conventional utility power is known as an "on-grid" or "grid-tie" system. Grid-tie solar systems draw energy from the sun during the day, which an inverter converts to traditional utility-type electricity to supplement the power drawn from a utility's power grid.
With grid-tie solar systems, buildings and residences draw their power requirements from the solar energy first, which helps to reduce dependency on conventional utilities. Utility power provides any additional power required to maintain critical loads. Grid-tie solar power systems both lower electric bills and protect the environment.