How Do Solar Farms Work?

The Climate Change Act 2008 states that greenhouse gas emissions have to be reduced to below 80% of 1990 levels by 2050. The United Kingdom also has a legal requirement to generate 15% of its energy requirements from renewable resources by 2020. This means big changes to how our electricity is generated. The UK government will aim to reduce the carbon output by increasing the amount of renewables in the energy mix — and solar power is one of those renewables.

Power from the Sun

There are several methods used around the world to generate electricity from the Sun, but in the UK the best option is to use photovoltaics.

Solar cells generate electricity directly from sunlight using a process known as the photovoltaic effect — where the energy of photons from the sun is absorbed and generates an electromotive force. This force can be used to generate an electric current.

Photovoltaics in the form of solar cells are used in many different devices from calculators to spacecraft. But increasingly, photovoltaics are being used to generate electricity for domestic and industrial use — and this could help benefit us in the battle against anthropogenic climate change.

Solar Farms

The most economical way to use photovoltaics is to create solar farms — large numbers of photovoltaic cells in a single location. In the UK they can cover large areas of land, and this has generally meant they are in rural locations.

Using 25 acres of land, a solar farm in the UK could generate enough electricity for over 1500 homes — this could save around 2100 tonnes of carbon dioxide per year from being emitted into the atmosphere. The farms work by feeding their electricity into the national grid. Because there is no way to store the electricity generated by photovoltaics, the electricity is only available at certain times and in variable quantities determined by sunlight. An additional benefit of solar farms in supporting biodiversity in the countryside has been recognised by several UK organisations, including the RSPB.

Rooftop Farming

However, using farmland to create solar farms is a controversial topic — some people feel that farmland is needed to feed people and that large solar farms can spoil the landscape, a point discussed in Pickles blocks solar farm. In October 2014, the Government announced a reduction in the subsidies available to farmers who use farmland for solar farms. So where can we farm?

The preferred option is to site solar farms on the rooftops of factories and other buildings. For many organisations, this can lead to a reduction in their energy costs as the solar farm can feed straight into the plant during operating hours. When the electricity is not required, it then diverts into the national grid where it is bought by other consumers.

With controversies about all the different energy sources in the UK — from nuclear to fracking to solar — what power do you want to turn on your lights and what price will you pay?