How solar PV works

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 cells containing a photovoltaic material.  Materials presently used for photovoltaics include monocrystalline silicon, polycrystalline silicon, amorphous silicon, cadmium telluride, and copper indium selenide/sulfide. Due to the growing demand for renewable energy sources, the manufacturing of solar cells and photovoltaic arrays has advanced considerably in recent years.

As of 2010, solar photovoltaics generate electricity in more than 100 countries and is the fastest growing power-generation technology in the world. Between 2004 and 2009, grid-connected PV capacity increased at an annual average rate of 60 percent, to some 21 GW.  Such installations may be ground-mounted (and sometimes integrated with farming and grazing) or built into the roof or walls of a building. This is known as Building Integrated Photovoltaics or BIPV for short.  Off-grid PV accounts for an additional 3–4 GW.

 

Driven by advances in technology and increases in manufacturing scale and sophistication, the cost of photovoltaics has declined steadily since the first solar cells were manufactured.  Net metering and financial incentives, such as preferential feed-in tariffs for solar-generated electricity, have supported solar PV installations in many countries.

In the UK, the introduction of the feed-in-tariff in 2010 caused a ten fold increase in installations in one year, jumping from 4.5MW to 45MWp in less than 12 months.  This rate is increasing as home and business owners and investors realise the profitability and effectiveness of the technology.