ABOUT PV SOLAR
HOW DOES PHOTOVOLTAIC SOLAR WORK?
How does PV technology work?
Photons strike and ionize semiconductor material on the solar panel, causing outer electrons to break free of their atomic bonds. Due to the semiconductor structure, the electrons are forced in one direction creating a flow of electrical current. Solar cells are not 100% efficient in part because some of the light spectrum is reflected, some is too weak to create electricity (infrared) and some (ultraviolet) creates heat energy instead of electricity.
Solar Photovoltaics (PV), a technology that converts sunlight into electricity is used primarily for grid-connected electricity to operate residential appliances, commercial equipment, lighting and air conditioning for all types of buildings. Through stand-alone systems and the use of batteries, it is also well suited for remote regions where there is no electricity source. Solar PV panels can be ground mounted, installed on building rooftops or designed into building materials at the point of manufacturing.
The efficiency of solar PV increases in colder temperatures and is particularly well-suited for New Hampshire's climate. A number of technologies are available which offer different solar conversion efficiencies and pricing.
Solar PV modules can be grouped together as an array of series and parallel connected modules to provide any level of power requirements, from mere watts (W) to kilowatt (kW) and megawatt (MW) size.
The size of the solar array, battery bank, and AC inverter required for a typical solar PV application depends on a number of factors, such as the amount of electricity you use, the amount of sunlight at the site, the number of days without backup that you require, and the peak electricity demand at any given time. Sufficient battery storage can easily allow a solar PV system to operate fully independently of a utility or genset back-up.
On the technology side, it is easy to interconnect your PV system to your local utility company -- there are no technical barriers. There may be regulations, however, that you will need to work through with your utility, in order for them to allow you to generate your own electricity.
PV modules should be oriented between south-east and south-west (due south is best). Modules generally need an unobstructed view of the sun all the year. Systems can be sized to provide 100 percent of your electricity consumption at a cottage or campsite, or as a supplement to conventional utility electricity or genset electricity. A tracking system can orient the solar array to maximize its electricity production throughout the day and the year by tracking the movement of the sun, though this is typically not practical for most applications.