Photovoltaic Panels

Photovoltaic (or "PV") technology is the technology to generate electricity from light (the literal meaning of "Photovoltaic"). Whilst PV has existed since the space programme in the 1950s, the technology until recently has not been commercially exploitable relative to the price of buying electricity from the grid.

Photovoltaic panels are a "sandwich" of positive and negtive semi-conductor material which when stimulated by light, causes a flow of electrons around an internally sealed cell. When grouped in series, the voltage of two cells doubles, while the current remains constant. When grouped in parallel, the current doubles, while the voltage stays constant. Consequently any combination of voltage and current can be achieved according to the way in which panels are grouped into an array.