The sun produces a lot of energy every year, which we call solar energy. The sun radiates 20,000 times more energy on Australia every day than we get from oil, gas and coal, and it is inexhaustible for us over the remaining five million years of the sun's life.

Solar panels are made up of solar cells, which convert solar energy from sunlight into electricity. Because solar cells can generate electricity directly from sunlight, it is one of the most reliable of all the power generation technologies that we have nowadays, which is why solar cells are widely used in space and in remote areas where it is difficult to solve problems.

How do solar cells work?

Solar cells are made up of silicon atoms. Think of the atoms as bricks on a building - like Lego blocks - but because the atoms are so small, you need special tools to see them. Solar cells come from layers of silicon wafers, which are similar in size to dinner plates, but much thinner - only roughly three times thicker than an average hair.

A special preparation process is needed to turn the layer of silicon crystals into solar panels. The layer of silicon crystals is heated to 1,000 degrees Celsius, and then a sheet of metal is placed on the back side of the layer, while the solar cells are covered with a metal mesh with holes in it and this side is exposed to the sun.

When the 60 solar cells have been prepared, they will be fixed to a layer of glass to make solar panels. Typically, a solar power system on a roof has 10-50 solar panels, while millions of solar panels are installed in solar power plants in the countryside.

Each silicon atom contains extremely small-sized, lightweight electrons that carry a weak electrical charge. When sunlight falls on a solar panel, it strikes one of these electrons and sends it out of its orbit. These struck electrons are free to move around, but the special construction of the cell allows the electrons to move only in one direction toward the sun.

So when sunlight falls on a solar cell, many electrons will get out of their orbits and become free electrons, and because of the nature of solar cells, the electrons can only move upwards, creating an electric current that can drive household appliances.

If the sunlight falling on the solar cell is stronger, more electrons will be knocked out of their orbits, and more current will be generated. If the weather is not clear, fewer electrons will be hit and the current generated will be reduced by 75% or more. At night, the solar panels do not produce any electricity and rely on batteries or other sources of power.

How do we use solar cells?

Solar cells are the cheapest way to generate electricity - even cheaper than a new coal or nuclear power plant. That's why the global installation rate of solar cells is five times that of coal power and 20 times that of nuclear power.