Dr Deane Hutton - Solar Energy

SOLAR ENERGY

The Sun is a huge ball of fire. Its temperature is around 6,000 degrees Celsius at the surface and more than 14 million degrees in the centre. The Sun is a fairly young star - only 4,600 million years old! And it will be around for a long time - at least another 5,000 million years.

More energy reaches Planet Earth, from the Sun EACH DAY, than we need for a whole year. But we're not very good at catching and using Solar Energy from the Sun. However, we are getting better every year.

Solar Energy can be captured and used in two quite different ways - solar thermal panels or solar photovoltaic panels.

SOLAR THERMAL PANELS

With solar thermal panels, metallic pipes are covered with a black heat-collecting surface. Water passes through the pipes and absorbs heat energy from the sun. The hot water can be used to heat homes or swimming pools. In newer solar thermal systems, lenses and reflectors are used to concentrate the sun's energy and increase the heating effect. In large scale solar thermal systems, the water boils to produce steam which can then be used to drive turbines and produce electricity. Power produced in this way is a zero-emission electricity source. Large scale solar thermal power stations have been established in India, Spain and Morocco. In Australia, the federal government will fund the development of several large scale solar thermal power stations in the near future.

SOLAR PHOTO VOLTAIC PANELS

Solar photovoltaic (PV) panels work on a different principle. Photo means light and voltaic means electricity. PV panels convert light energy directly to electrical energy. The PV panels are made of silicon. When hit by light, silicon atoms release electrons which are collected and sent through an external circuit - providing electrical power.

In Australia, more than 40,000 homes have solar PV panels on the roof - providing electricity for the house. In 30% of these homes, surplus electricity can be sold back to the grid. The Australian government has implemented incentive schemes to encourage more homes and businesses to install PV panels.

New developments in PV panels in the next few years will result in amazing new options. These will include: flexible PV panels which can be attached to any surface; transparent PV panels which can be installed on glass windows; and sliver cells which are much smaller and cheaper - and use less silicon.

THE FUTURE

Since Australia is one of the sunniest continents on Planet Earth, there is a huge potential for both solar thermal panels and solar PV panels. The federal government is committed to ensuring that 20% of our electricity supply will come from renewable sources by the year 2020.