How Solar Energy Works

Solar - the obvious energy choice for the future

When you think about it, the ability to make electrical power from sunlight is a marvellous process. Solar power technology is 100% carbon free, renewable, clean, silent and highly durable.

And how much nicer is it to flick on a light switch at home, or cook a meal, knowing that just like a natural ecosystem you've harnessed the power of sunlight to do so.

It makes the burning of fossil fuels to produce electricity seem like an old dirty habit.

How does solar energy work ... and what is its history?

As far back as 1839, a 19yr old Frenchman called Edmund Becquerel, discovered what is called the photovoltaic effect, the physics behind the solar cell, while experimenting with a couple of metal electrodes. His process was refined over the following decades by pioneering scientists, and in 1923 Albert Einstein received the Nobel Prize for his theories explaining the photoelectric effect.

In the early 1950s the first uses were made of the photovoltaic cell, sometimes referred to as PV cells. These cells are produced from extremely thin wafers of silicon.

When sunlight hits these cells, electrons are shaken free and move around. Electrons are the negatively charged particles that sit around the nucleus of an atom (the nucleus consists of protons and neutrons). An electric current is simply the movement or flow of electrons in the same direction. A bolt of lightning, for example, is a sudden surge of electrons across a build-up of charge within clouds, or between clouds and the ground.

Now, if you place a group of these PV cells together in a panel, and install a number of panels side by side, you can create a flow of electrons and DC electricity. Households however use AC 240 volts, so a box called an inverter - usually no bigger than your average shopping basket - is used to convert the electricity for your immediate use.

It's important to remember that even an overcast or rainy day is sufficient to generate some solar power, albeit less than in broad sunshine. No maintenance is required other than to not let the panel get dirty. Solar panels should last you for decades.

Solar energy has come a very long way since 1958 when the first solar powered satellite was launched. With the recent advent of nanotechnologies, the efficiencies of the PV cell are now many times what they used to be. Now it takes far less roof space, and far less expense, to fully solar power an average home.

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