In the UK, we have a temperate climate and ‘benefit’ from fairly moderate but changeable weather conditions. We certainly can’t claim to be the sun capital of Europe. I was therefore a little surprised the other day as I drove down a major road near my home, to notice that there was a sign at the side of the road pointing to the site of a solar farm which is currently under development. This got me thinking about solar energy, and wondering about just how a solar farm actually works.
Basically, a solar farm is a flat field covered with high technology glass panels called photovoltaic modules, that collect sunlight and convert it into electricity. The panels themselves are made up of slender silicon wafers called photovoltaic cells, with about 60 cells wired together within each panel and protected by a glass covering. When the photons contained in sunlight fall on these cells, they produce a small electric current – roughly 12 volts for each panel.
Do we get enough sunlight here?
The answer is ‘yes’ – modern solar panel technology has advanced in recent years, and not only do they require less intense sunlight in order to generate a reasonable amount of power, they cause much less glare than older technology panels. The panels have a coating that absorbs 90% of the sunlight, with only 10% reflected. The coating also diffuses the reflected light, and it is claimed that natural grass actually produces more glare than the panels.
The best locations for solar farms are apparently in the South West of England, but land there is in short supply and comes at premium cost, hence the Shotwick facility is being built in North Wales where there is more space and lower costs. This actual site was chosen because it is a flat area of formerly agricultural land, there are no buildings or hills to overshadow the modules, and the site has good road access from the nearby major road system. Add to that the location nearby of an electricity grid and nearby factories that need power and you have a potentially successful solar park that apparently will generate 45MW.
Low pollution energy production
If we can believe the site designers, once construction on the site has been completed, the solar farm will quietly get on with producing low noise, low pollution energy for the foreseeable future, with a minimal need for heavy machinery to access the site. The glass apparently needs cleaning several times per year, but the panels are designed to go on working out in the open for the next 30 years without much further interference, and then the whole apparatus can be dismantled and the site returned to its original purpose if required. There are many solar farms spread across the UK, all helping to do their bit to solve our impending energy crisis, without contributing to global warming.