How Do Photovoltaics Work

How do photovoltaics work

Solar cells make use of the photoelectric effect. Simply put, when light falls onto certain materials, it allows tiny charged particles to move. Photons, or light particles, transmit their energy to electrons. Through a clever design, these electrons can then be collected from the solar cell surface thereby generating a current. In fact, the only thing that ever moves in a solar cell is electrical current. This is one reason for their high durability and low maintenance - no moving parts means little wear.

Solar cells are mass produced from semiconductor materials today. The most important of these is silicon - a very abundant element. In fact sand is an oxide of silicon, a raw material we won't run out of. The active light absorbing layer of solar cells is very thin - about two tenths of a millimeter, or even less. Many years of research have gone into increasing the amount of current generated per cell area, and reduce the cost of making them.

Light is the energy source for photovoltaics. Every year, about 1000 kWh of solar energy fall onto every square meter of land in the UK - equivalent to about 100 liters of crude oil. Commercial photovoltaic systems today convert 10-20% of that energy to electrical power. Both the direct sunlight of a cloudless day and the diffuse light scattered by clouds can be turned into clean electricity.

Introduction to photovoltaics
How do they work
Who uses them
Why photovoltaics
What can they do for you
Why now
Frequently asked questions