Solar Power

What is Solar Power?

Solar power is energy from the sun. There are two main ways in which the energy can be captured, we can either capture the light energy with photvoltaic cells or the heat energy with solar collectors.

Photovoltaic cells

Photovoltaic cells convert light directly into electricity. This process happens at an atomic level, photons are absorbed and electrons are released, creating electricity. PV cells produce Direct Current (DC) electricity meaning battery banks can be charged without the need for rectifiers (a charge controller will still be needed).

The photovoltaic phenomenon was discovered in the 18th century by a French physicist, Edmund Bequerel, he noticed that certained materials produced small amounts of electricity when exposed to light. Bell Laboratories went on to build the first photovoltaic cells in 1954, at first the cells were built to be used in spacecraft.

There are two main types of modern photovoltiac cells, amorphous cells which consist of a thin film of silicon on a sheet of another material such as steel and crystalline cells are made from a single crystal or a polycrystalline slice of silicon.

A typical home solar power setup would consist of one or more photovoltiac panels, a charge controller, a deep cycle battery and an inverter. The solar panels produce the electricity (normally 12v DC), the charge controller then ensures that the batteries are not over/under charged. An inverter will then take the 12v DC from the battery and convert it into 240v AC.

Solar Thermal

The heat from the Sun can be used to heat many things, although the main use is to heat water. Most people will have noticed that in the summer the water from a hosepipe left out in the Sun can get quite warm. Solar collectors use the same principle but utilise a more efficient design. Many designs use metal tubes enclosed in an evacuated glass tube, while simple DIY designs use a series of copper pipes inside an insulated box with a glass cover. The hot water from a solar collector can be used for domestic hot water or for heating swimmng pools.