Solar (Photovoltaic Systems)
A photovoltaic system uses one or more solar panels to convert sunlight into electricity. The system consists of multiple components (photovoltaic modules, mechanical and electrical connections, and a means of regulating electrical output). To compensate for the low voltage of an individual solar cell, cells are wired in series known as a solar panel (or laminate). Solar panels are then strung together into a solar array (or photovoltaic array/PV array). The electricity generated can be stored, used directly, or fed into a large electricity grid. Most PV arrays use an inverter to convert the DC (direct current) power produced by the modules into AC (alternating current) power. Costs of production have been reduced in recent from advances in production and technology.
PV Systems (Solar Arrays)
Solar arrays are commonly installed on rooftops to supplement power use. In cases where building has a connection to the power grid, excess energy can be sold back to the utility with a net metering agreement. In remote settings, solar arrays can be used as the sole source of electricity by charging a storage battery.
Standalone PV Systems
A standalone system does not have a connection to the electricity grid. Standalone systems vary widely in size and application from calculators to buildings. In small devices only direct current (DC) is consumed while n larger systems (e.g. buildings, remote water pumps) AC is usually required in which case an inverter is used.
Grid Connected PV Systems
A grid connected system is connected to and feeds power into the electricity grid. Grid connected systems vary in size from small building mounted systems to solar power stations. This is a form of decentralized electricity generation. In the case of building mounted PV systems, once the demand of the building is met, the excess electricity is fed into the grid. The feeding of electricity into the grid requires the transformation of DC into AC by a grid-controlled inverter.
A plane that is perpendicular to the sun's rays on the Earth's surface is the ideal location for capturing solar energy (i.e. high noon on a cloudless day at the equator). PV arrays can track the sun through to greatly enhance energy collection; however, tracking devices add cost and require maintenance. It is not uncommon for PV arrays to have fixed mounts that tilt the array and face due South in the Northern Hemisphere to give optimal array output during the peak electrical demand portion of a typical year.