How Do Solar Panels Work?

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, for us, it is inexhaustible for the remaining five million years of the sun's life. Solar panels are made up of solar cells that convert the solar energy from the sun into electricity. Because solar panels can generate electricity directly from sunlight, it is the most reliable of all the power generation technologies we have today, which is why solar cells are widely used in space and in remote areas where it is difficult to solve problems.

How do solar panels work?

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

The silicon wafer layer is heated to 1,000 degrees Celsius and then a metal sheet is placed on the back of the layer, while the solar cell panel is covered with a metal mesh with holes and this side is exposed to the sun.

When the 60 solar cells are prepared, they are fixed on a layer of glass to make solar panels. Generally, a solar power system on a roof has 10-50 solar panels, while in rural solar power plants millions of solar panels are installed.

Each silicon atom contains electrons of extremely small size and light mass, which carry a weak electric charge. When sunlight falls on a solar panel, it strikes one of the electrons and causes it to break out of its electron orbit. These struck electrons are free to move, but the special construction of the cell allows the electrons to move only in a direction toward the sun.

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

If the sunlight falling on the solar cell is stronger, more electrons will be hit to get out of their orbit, and the more current will be generated. If the weather is not clear, the number of electrons hit will be reduced and the current generated will be reduced by 75 percent or more. At night, solar panels do not produce any electricity, and the power supply at this time is entirely dependent on batteries or other sources of electricity.

How do we use solar panels?

Solar panels are the cheapest way to generate electricity - even cheaper than a new coal-fired 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.

In Australia, essentially all new power stations built are solar or wind power plants. Electric cars using solar and wind power can replace gasoline cars that produce pollution. Solar and wind power can also be used to heat and cool homes, replacing traditional coal and natural gas heating methods.

The use of solar and wind power can help reduce earth-damaging greenhouse gas emissions, which are cheap compared to other energy sources and will become even lower; if we use more wind or solar power, we can accelerate the reduction of conventional energy use (such as coal, oil and natural gas) that is harming the planet.

On top of that, the silicon atom is the second most abundant atom in the world (first is the oxygen atom). In fact, most sand and rocks are made of silicon and oxygen, so it is unlikely that we will use up all the silicon we have for preparing solar panels.