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How do solar panels work? |

Posted in: Solar Energy

Posted on: 12.11.2015

Since last year, Good Energy has developed six solar sites – and in that time nearly a quarter of our 100% renewable fuel mix came from the power of the British sun.

We’re proud to be part of the record growth of solar – in July it was reported output had jumped 153% compared to 2014! 

At the same time, there have been lots of great innovations in solar technology – scientists have developed solar panels you can paint onto any surface, made solar panels that are transparent and developed solar roads.

Solar panels are getting more and more efficient at converting the sun’s energy to electricity all the time, so we thought now might be a good opportunity to explain what’s going on in those quiet shiny sheets...

A solar panel is made up of photovoltaic cells. Each cell is made of two layers of semiconductor materials with different electronic properties. When exposed to sunlight, electrons are transferred between the two layers.

An electrical circuit is made and energy is produced – this is known as the photoelectric effect.

Solar panel facts

  • Most solar panels react to the visible spectrum, as these are the wavelengths with the strongest energy. Ultraviolet and infrared rays will be lost as heat.
  • Some wavelengths are blocked by elements in the atmosphere, or diffused by clouds. This is taken into account when panels are being designed.
  • Panels of the future will make better use of the spectrum: different electrical properties of the semiconductor materials will allow more wavelengths to be absorbed.


What happens to solar panels on cloudy days? 

Our trading team always keep one eye on the weather because cloudy days mean less output from solar sites. However, even on a cloudy day solar panels will still generate: as we’ve said above, they work using the same light we use to see – so if it’s light enough to see, they’ll be generating!

In the video below you’ll see a very variable day at our Lower End site, where the clouds result in dips in generation output. However, by 10am this site on this day still generated enough to power one average household for a whole year – you can watch its output over the same period as this film on our youtube channel.


Solar panels in the UK


It’s not the sunniest place in Europe, but the UK’s south has similar solar levels to Germany – where 7% of electricity comes from solar power.

The fact that we have cooler and cloudier weather can also help solar panels in ways you might not expect: in cooler temperatures the solar panels will work more efficiently, rain clears dust from the atmosphere to let more sun through and snow cleans the panels as it slides off the sloping surface.

We source all of our electricity from British sunshine, wind and rain. You can switch for good online or call our friendly team on 0800 254 0000.

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