PV SOLAR – How It Works In Simple Terms

By converting light into electricity. We use a system called Photovoltaic (or PV for short), which generates electricity by using daylight on silicon solar cells normally located on your roof. When the electricity generated by the silicon solar cells is not being used, it can be sold back to your energy supplier then taken back from the national grid when there is no daylight and you have a demand for energy, Silent and virtually maintenance free a solar roof not only adds value to your home, it produces clean electricity helping to protect generations to come and to provide you with a generous income.


The Technical Part

pv2The solar cells are made of several thin layers of silicon. When sunlight strikes, the electrons within the cell are knocked loose. By the absorption of a photon (light particle), the negative electron gets shunted away from the silicon atom, and a positive ‘hole’ remains. The freed electron and the positive hole together are neutral. Therefore, to be able to generate electricity, the electron and the hole need to be separated from each other. This is done by giving layers within the cell opposite charges, so that the freed electrons cannot return to the positively charged holes. When the electrical contacts on the front and rear are connected through an external circuit, the freed electrons can only return to the positively charged holes by flowing through this circuit, thus causing electricity to flow. This means that the greater the intensity of light (larger number of photons), the greater the flow of electricity.

…and what happens if the sun isn’t out?

Even if the sky is overcast, PV still produces electricity. This is because PV cells not only use direct sunlight, but also diffuse solar radiation, which is light that has been scattered by dust and water particles in the atmosphere. Obviously the amount of useful electricity generated is proportional to the intensity of light energy which falls into the conversion area. However, you can still have an electricity supply even without the sun!

To determine the PV electricity generation potential for a particular site, it is important to assess the average total solar energy received over the year.