How it Works:

Solar Panels are made of cells or thin film circuits that are specially manufactured to respond to sunlight by producing electric current. The scientific term for "solar electricity" is "Photovoltaic" energy, which means "electricity from light." The more light the cells get, the more electricity that can be produced. When all of these cells are connected together, laminated and framed, they are called solar panels or sometimes called PV (Photovoltaic) modules.

Solar panels are designed to produce electricity at convenient direct current (DC) voltages for storing in a battery or being directly converted into typical 120-230 volt alternating current (AC). Beside solar panels, PV systems have several individual components including inverters, controls, safety disconnects, and batteries. By assembling different sizes of components together, systems can be built with varied power outputs to meet the demands of various loads. Most American household appliances are designed to run on a standard (120 vac) power rather than 12 or 24 volts DC. Combining batteries with an efficient AC inverter allows you to use your standard appliances with solar electricity. Also solar electricity can be used to run DC motors, or it may be stored in batteries for later use, or converted instantly into AC power and "net metered" into the utility grid depending on the local power company in your area.

Solar electric systems (or PV systems) may be categorized into three primary types, stand alone system, back-up system and grid tie system. Any of these systems may be designed to meet all or part of the user's electrical requirements.

Stand alone type systems are usually a utility power substitute. They generally include solar panels that can be roof mounted or ground mounted., inverter, charge controller, safety disconnects and storage batteries. The batteries used for stand alone solar electric systems are different than the ones used in a automobile. Batteries used for solar electricity are called deep cycle batteries and are designed to be recharged many times and be able to provide a steady amount of power over a long period of time. Some stand alone systems also include a fuel power generator or wind turbine to share the load and as back-up power to your PV system.

Back-up type systems use utility power to back-up your solar electric system. This system includes multiple solar panels that are roof mounted or ground mounted, one or more inverters, controller, safety disconnects, and batteries. The utility power will back-up the solar system and run the loads when sunlight and battery power is not available.

Grid tie systems are probably the easiest system because it doesn't require any batteries. These systems are not designed for back-up power but instead they are designed to contribute power back into the existing power supply. So basically, it reduces power demands from the power company by 'net metering' power or in some cases to sell back to power company. This also would depend on what your local utility company allows in your area.