How Solar Photovoltaic (PV) systems work
Photovoltaics or PV is a way of generating direct current (DC) from sunshine. When light strikes a solar cell, it knocks electrons free in the cell silicon crystal structure which then travel through wiring as electrical current to a load then return to the solar cell to start the process over again.
Flat-plate collectors, which typically contain a large number of solar cells mounted on a rigid, flat surface, can make use of both direct sunlight and the diffuse sunlight reflected from clouds, the ground, and nearby objects.
PV systems are simple!
Other than safety disconnects, mounting structure and wiring, all you need for grid-tie systems are collector panels and an inverter, and for battery back-up or stand alone systems you will also need batteries and a charge controller.
A Collector is a panel made up of several individual solar cells; several panels assembled together are called an array.
An Inverter is a device to convert direct current (DC) into alternating current (AC). Most homes and building run on AC power.
Batteries would be needed if you plan to store the electrical energy that your PV system produces. A charge controller is used to prevent a battery from being overcharged , and eliminates reverse current flow from the batteries to the collectors at night.
Solar will work anywhere though some locations are better than others because they may get more full hours of sun. New England may receive between 4-5 hours of full sun per day whereas California might receive 5-51/2 hours.
If your site is in the Northern Hemisphere you need to aim your solar panels as close to true south as possible to maximize your electrical production. Ideally the panels should be tilted up from horizontal at a tilt angle equal to your latitude.
For more information visit http://www.eere.energy.gov/RE/solar.html
