How Solar Works
Photovoltaic technology using silicon semiconductor material has been in development since 1954, yet only recently has the technological advancement been so effective and the cost so low that it has become widespread in its commercial application. Photovoltaic modules contain a series of semiconductor cells most often made of silicon, the same material used in other electronic devices such as microchips. These cells transform light photons, which are absorbed into the semiconductor material, into electricity by the flow of electrons within the cell. The cells are connected in a series to make a module, which produces an electrical current (direct current) which is harnessed and distributed through the array. The array is, in turn, connected to an inverter, which converts the DC to AC and then delivers the AC to the main service panel for consumption.
Most electricity is generated by utilities centrally, at a power station, and then transmitted through high voltage lines to substations and then ultimately distributed to commercial businesses and households for consumption. Distributed generation involves the generation of electricity at or near the point of consumption, reducing the amount of power lost over transmission lines and enhancing energy independence. Yet, distributed generation does not mean that the user is isolated from the grid. To the contrary, users of distributed generation are most often interconnected to the grid in a net metering arrangement whereby when the solar modules are not producing electricity, the user simply draws from the grid in a manner identical to its current situation. When excess electrical power is produced from the solar array, the electricity is fed back to the grid causing the meter to spin backwards and thereby create a credit with the utility.
PV solar may be the most environmentally sound form of renewable energy production. In the United States, approximately 48% of electricity is generated by coal burning power plants. A solar energy system captures the energy from the sun and produces no harmful emissions or pollutants, and displaces electricity otherwise generated by these carbon emitting electricity sources. In fact, according to EPA estimates, 60 kW PV solar system is expected to offset the emissions of more than 1,260 tons of pollutants such as CO2, SO2 and Nox over the system’s 25 year life. This is equivalent to removing 312 automobiles from our highways.
PV solar is quiet and unobtrusive. And PV solar does a small but important part to reduce our dependence upon foreign energy sources.