A popular question that brings people to the Good Energy website is how do wind turbines work? Wind farms produce the biggest proportion of the renewable electricity that we use here in the UK.
So here’s (almost) everything that you need to know about generating electricity from the wind.
How do wind turbines work?
Wind turbine blades rotate when hit by the wind. And this doesn’t have to be a strong wind, either: the blades of most turbines will start turning at a wind speed of 3-5 meters per second, which is a gentle breeze.
It’s this spinning motion that turns a shaft in the nacelle – which is the box-like structure at the top of a wind turbine. A generator built into the nacelle then converts the kinetic energy of the turning shaft into electrical energy. This then passes through a transformer, which steps up the voltage so it can be transported on the National Grid or used by a local site.
From a micro wind turbine for home energy generation right up to enormous, off-shore windfarms, all wind turbines use the same mechanics to generate electricity.
How much power does a wind turbine produce?
Most onshore wind turbines have a capacity of 2-3 megawatts (MW), which can produce over 6 million kilowatt hours (kwh) of electricity every year. That’s enough to meet the electricity demand of around 1,500 average households.
Up to a certain level, the faster the wind blows, the more electricity is generated. In fact, when the wind speed doubles, up to eight times more electricity is generated. But if the wind is too strong, turbines will shut themselves down to prevent being damaged.
All this means that the ability of a wind turbine to generate the maximum amount of power it can depends on the wind. Wind farms are carefully planned to make sure they’re in locations with a reliable amount of wind all year round. This tends to be on the summit of a hilltop with lots of open space around, and in coastal locations. That is why there are quite a lot of wind farms in places such as Cornwall and Scotland.
Why does the UK have so many wind farms?
There are over 11,000 wind turbines in the UK, including onshore and offshore wind farms. They’re popular because the UK’s exposed position on the north-western edge of Europe makes it particularly windy, with Scotland being the windiest place in the whole of the continent.
The wind blows all year round – making wind power a reliable renewable power source. It also tends to be windiest in winter, meaning wind turbines can produce are producing more power at the time of the year when we’re also using the most electricity.
Both of these points make the UK well positioned to make the most of both offshore and onshore wind energy and reduce our reliance on fossil fuels.
Another added bonus is the low carbon footprint that is created in building wind farms – it’s one of the smallest among new renewable generators.
How much electricity comes from wind power?
The latest information from National Grid finds that just over 26% of the UK’s electricity is generated from wind power. In 2013, this percentage was just 7%, demonstrating just how fast wind power capacity in the UK is growing.
How many wind turbines are there in the UK?
There are over 8,800 onshore wind turbines and 2,300 offshore turbines in the UK. Go to RenewableUK for the latest statistics. Altogether, they produce enough power to meet the annual electricity demand of around 18 million homes.
At Good Energy, we buy power from independent renewable generators, many of whom generate electricity using wind power.