Ecotricity explains: sun parks

Ecotricity is Britain’s greenest energy company, thanks to the unique way we work.

We don’t have shareholders, and we don’t pay dividends. Instead, we use 100% of our profits to build new sources of green energy in Britain, turning your bills into mills.

Right now, we have two new sun parks under construction. They’re being built with the latest solar panel technology next to our existing wind parks at Dalby, Leicestershire and Bulkworthy in Devon.

How does solar energy work?

All sun parks work in essentially the same way. The great advantage of solar power is that we can have hundreds or thousands of solar panels – or solar mills, as we like to call them – sitting in a field, silently producing clean, green electricity whenever the sun shines.

Each solar mill contains a number of photovoltaic cells. These are made from specially treated layers of silicon sandwiched together.

When a photon from a light source hits the upper layer of silicon, it knocks an electron free and this creates electricity in the form of direct current (DC).

We use an inverter to change this into alternating current (AC) which is the type of electrical current our appliances use when they’re plugged into standard wall sockets. Finally, the electricity is fed into the national grid via a connector to power our homes and businesses.


How much sunlight do solar panels need?
Solar panels generate electricity whatever the weather, all they need is light. The amount of electricity they produce does vary according to the strength and direction of the light, so they’ll tend to produce more on sunny summer days when the sun is high in the sky for a longer time.

Temperature extremes can also affect how much electricity solar panels generate. In Britain we rarely see temperatures high or low enough to be a problem, and we get lots of daylight hours even in the middle of winter, so solar is a great choice for sustainable electricity.


How big are our new sun parks?

The Dalby sun park in Leicestershire will produce around 12 megawatts, supplying the equivalent of around 4,200 homes with electricity every year.

The Bulkworthy sun park in Devon will generate around 7.8 megawatts – enough to power over 2,800 homes with electricity every year.

In total, that’s solar capacity for around 7,000 homes being built right now. And of course, we have more sun parks in the planning stages.


What technology are we using in our new parks?

The sun parks in Leicestershire and Devon will use the latest bifacial solar panels. They generate electricity from the underside as well as the top face, from light reflected off the ground – overall, they generate up to 10% more electricity than conventional panels in the same space for a very small cost difference.

We considered using solar panels that move to track the sun across the sky through the day for both sites but the figures didn’t work out. While they generate more energy, they also need more room to stop them shading each other, which means we would have had to reduce the number of panels. We’d consider this on larger sites, where there’s a bit more breathing space for the solar panels.


How does the solar energy travel around the country?
Solar generated electricity is fed into the National Grid, which is the network that supplies energy to homes and businesses throughout the country.

It travels at high-voltage and must be stepped down using substations and transformers dotted around local areas before it can be used. By the time it reaches your home, it’s at the right voltage for your appliances.


Are sun parks the way to a green Britain?
There are so many advantages to solar energy. Solar panels don’t make any noise when they’re producing electricity and they’re incredibly safe – there’s nothing to leak out or contaminate the area in the event of damage.

We also use our sun parks as opportunities to rewild areas of the sites wherever we can, helping to support Britain’s wildlife and giving local communities a place to go and connect with nature.

We invest our customers’ bill money in this as well as other sources of green power, like wind, geothermal and soon, sustainable gas from grass. We’re also constructing our first grid-scale battery, an essential technology that will enable us to store excess electricity until it’s needed at times of peak demand.