Photovoltaics

Photovoltaics (PV) is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect. Photovoltaic power generation employs solar panels composed of a number of solar cells containing a photovoltaic material.

A photovoltaic system  is an arrangement of components designed to supply usable electric power for a variety of purposes, using the Sun (or, less commonly, other light sources) as the power source. Solar PV total global capacity increased during 2010-2013 from 40 GW to 139 GW. In 2013 Germany had the most capacity (36 GW) .

• Off-grid without battery (array-direct)
• Off-grid with battery storage for DC-only appliances
• Off-grid with battery storage for AC and DC appliances
• Grid-tie without battery
• Grid-tie with battery storage

A small PV system is capable of providing enough AC electricity to power a single home, or even an isolated device in the form of AC or DC electric. For example, military and civilian Earth observation satellites, street lights, construction and traffic signs, electric cars, solar-powered tents, and electric aircraft may contain integrated photovoltaic systems to provide a primary or auxiliary power source in the form of AC or DC power, depending on the design and power demands.

The average family home needs a solar PV panel that provides about 3kW of electricity. This will cost between £4,000 and £6,000 and cover about 21m² of roof space.

While this may seem like a large sum you will actually make this back in about ten years because the government pays you for the electricity you produce and you save money on your energy bills.

The government payout is called the Feed-in tariff and it lasts for twenty years.

The price of a solar panel will vary depending on the quality and size .

Solar PV needs little maintenance – you'll just need to keep the panels relatively clean and make sure trees don't begin to overshadow them. In the UK panels that are tilted at 15° or more have the additional benefit of being cleaned by rainfall to ensure optimal performance. Debris is more likely to accumulate if you have ground mounted panels.If dust, debris, snow or bird droppings are a problem they should be removed with warm water (and perhaps some washing-up liquid or something similar – your installer can advise) and a brush or a high pressure hose (or telescopic cleaning pole) if the panels are difficult to reach.