What happens when the wind doesn’t blow?

In the last decade, wind turbines out to sea and on land have gone from producing less than 2% of our electricity to 11% in 2015. Sometimes it’s windy and the turbines produce more power, sometimes it’s not that windy and they produce less. But they still produce enough electricity to power 30% of UK homes. And they haven’t caused any blackouts.

Wind turbines do cause some variations in electricity supply for the National Grid. But it’s predictable (we’re pretty good at predicting the weather these days!). We can plan for wind generation with a high level of certainty. Plus, energy secretary Greg Clark thinks the concerns about wind power’s intermittency have been ‘overblown’ and we’re more than able to deal with them.

What about as we build more wind turbines? Germany and Denmark are streets ahead of us when it comes to renewables - in 2015 Danish wind turbines contributed 42% of their electricity needs. And yet these are two of the most reliable energy systems in Europe, with four times fewer power cuts than the UK (pdf). A more diverse electricity grid (rather than one based on a small number of centralised power stations) means if something does go wrong with one part of the system, it is far less likely to cause big power cuts.

As we build more wind turbines in the UK, we can use demand management, interconnection (linking up with other parts of the country or other countries) and energy storage to help us manage. It will need a bit of thinking, but it’s well within our capabilities, and something we need to do as we move towards the cleaner, smarter, more efficient energy system of the future. And the government are already investing in it.

Wind would never be the only electricity source we use - it complements other sources like solar, hydro and tidal. But it is a pretty good one, especially in windy places like the UK. Wind turbines deliver two and a half times as much electricity (pdf) during periods of high demand (like cold winter nights) compared to times of low demand. There’s plenty we can make the most of.

If you’re wondering what happens when it’s too windy - we’ve also written about that!

Banner image: One Fine Stay, creative commons

What happens when it’s really windy?

On a blustery day, wind turbines will be turning and generating lots of lovely clean power. Last summer the Met Office issued a yellow weather warning for wind in Scotland. A few bridges were shut and ferries cancelled, but that was the day wind turbines produced 100% of Scotland’s power needs.

But when extreme weather and very strong winds hit, turbines sometimes need to be shut off. All modern wind turbines are are set to stop turning automatically if there’s too much energy in the wind. Some will shut down if the average speed of the wind is over a certain level for a period of time, while others will stop after a super strong gust (something like 100mph).

It’s pretty rare that we’ll see strong enough winds in the UK to stop the turbines - and certainly not to stop all of them. High winds affecting 40% or more of the UK’s turbines would occur in around one hour every ten years (pdf).

The reason turbines shut down like this is for safety - if the wind is too fast it can put major stress on the blades and mechanisms inside the turbine causing lots of friction and long term damage. It’s much safer to have the turbines stop and then start again when wind is a bit slower and safer.

It’s pretty straightforward to predict, too, so the National Grid know when there will be lots of wind power produced, and when they will have to switch off. That means they can easily plan for the variation.

The other reason turbines may stop turning on windy days is when there’s too much renewable energy being fed into the National Grid. The grid was originally built around a few centralised power stations, rather than lots of small generators feeding in. When it’s too windy and turbines are producing lots of clean power, the grid people ask some wind turbines to switch off to stop the grid from getting overloaded. This isn’t a problem with wind turbines, they’re just doing their job, the real a problem lies with the grid which needs to be upgraded to support a new smarter energy system.

If you’re wondering what happens when it’s not windy - we’ve also written about that!

Banner image: Nigel Goodman, creative commons.

Does anyone want to live near one?

Ten years ago, on the tiny island of Tiree, part of the Inner Hebrides, the community development trust were looking for ways to keep their community resilient. They chose a wind turbine.

Locals loved it so much, they gave her a name. Tilley the turbine has touched every aspect of community life - providing funding for a local shop, a minibus service for older people, restoring the museum, upgrading broadband, building a tourism app and community sailing. Tilley is a member of their community.

Across the board, you might be surprised by how popular onshore wind is. Three quarters of people support it as an energy source. That’s higher than nuclear and fracking.

Co-op Energy polled people to ask how likely it’d be that they support a wind turbine being built within two miles of their home. And they got a majority of people saying yeah, they’d likely support it (52%, in contrast to 19% saying it’d be unlikely they’d support it).

What’s more telling, perhaps, is research with people who actually do live near wind larger wind farms (pdf). They generally felt the turbines had a positive impact on the area, and those living closer to wind turbines or those who saw the turbines every day supported them the most. Or to put it another way, if you do have a wind turbine in your backyard, you probably like it.

The first wind turbine in Swaffham, Norfolk was built in August 1999. The closest house to the turbine was a farm owned by John Blackburn. Anti-wind campaigners came to visit him, assuming he'd hate being so close. He turned them away because he really liked them. So much, in fact, that he installed a small wind turbine of his own. 

In 2006 Ecotricity wanted to build ten more turbines nearby. How do the locals feel about that? Having lived harmoniously alongside these windmills for some years already, local people lodged no planning objections to the new wind farm.

Something else that’s interesting about the Co-op Energy polling is that they also ask how likely people would be to support local renewable energy projects if they were owned and controlled by the community, with the profits benefitting the community. Then the 52% goes up to 61%. Unlike a lot of other energy options - notably nuclear or oil - it’s pretty straightforward for communities to own their own wind power. If only the government would let us build them...


Banner image: Wakely Mulroney, creative commons

Are they an eyesore?

Aesthetics are a personal thing. It’s fine if you don’t like the way wind turbines look. But don’t assume everyone thinks the same way.

10:10er Leo Murray is a big fan: “I’ve always loved seeing wind turbines in the landscape, I think they look elegant and majestic. As someone more than a little bit concerned about climate change, I find the sight of wind power in action uplifting and deeply reassuring - perhaps we really are going to solve this problem after all.”

When you ask, it turns out that lots of people feel the same as Leo. Polling found that  66% of UK public find look of onshore wind farms acceptable. It’s normal to like wind power. Many people find them very beautiful, like Leo - proud and strong, little glimmers of hope on the horizon. Some people have even make wind turbines into art.

It’s understandable that people who know and love an area are used to the way it looks and find a load of wind turbines popping up a bit of an imposition. This is one of the reasons why 10:10 supports the involvement of local people in planning processes - we’d say the same for solar farms as well as offshore and onshore wind. Any bit of new energy infrastructure needs to involve the people who’ll live near it.

It’s also understandable that we want to keep some views wild, or at least kept within a vision of the countryside which we are used to (e.g. fields with sheep in them). Again, we think this is why onshore wind needs to be done well - with thought over where it is placed and with involvement of local people.

The main point we'd make, however, is that if you're worried about conservation, climate change is the greatest threat. And wind power is one of the key solutions we have available to tackle climate change.


Banner image: Brian McNamara, creative commons

Are they a health risk?

The health risks of wind turbines have been grossly overstated. As with a lot of these things, if you’re worried about public health, you should be focused on climate change, not wind turbines.

It’s reasonable that people should worry about the health impacts of a new technology. But it’s also important to check that these health impacts are real, not made up. Else you are scaremongering, which in itself can make people ill.

A study by Public Health Wales in 2013 concluded there was no evidence to suggest that noise from wind turbines has a direct physiological impact on health. They do, however, emphasise that the idea of ‘annoyance’ is pretty subjective and difficult to measure. Just because they aren’t bad for your health doesn’t mean everyone loves them.

Simon Chapman, Professor of Public Health at the university of Sydney's done some digging on so-called wind turbine syndrome - the idea that the noise of wind farms might cause a range of problems from heart disease to tinnitus, vertigo or panic attacks. He argues that anxiety and fear about wind turbines is being spread about by anti-wind farm groups, and that’s what’s causing some people to feel those symptoms. Or to put it another way, protests against wind farms make you ill, not wind farms themselves.

More seriously, there is something known as ‘shadow flicker’ which can affect people with autism or epilepsy. Shadows caused by moving turbine blades can cause a flicker effect through windows and doors where the contrast between light and shade is most noticeable.

But the people who build wind farms are a clever lot, and they know how to avoid this problem. UK planning regulations stipulate that shadow flicker should be considered - so you put the turbines in places that won't hurt people. This, plus the size and speed of modern turbines mean shadow flicker isn’t a medical risk.


Banner image: Michel Filion

Are they noisy?

Wind turbines do make some noise. But modern turbines are designed to minimise noise, and we have regulations about where turbines can be placed. General Electric say that, unless you’re up close, it shouldn’t be much more than a fridge’s hum.

10:10er Leo Murray had only ever seen a turbine from a distance, but his main worry was the noise. But as he went closer, he was pleasantly surprised: “On the day we visited all we could hear, standing right at the bottom of the turbine, was the traffic on the A47, some birdsong, and a very - very - faint whooshing sound.”

Wind turbines rely on mechanical movement of blades through the air, and this inevitably creates some noise. But if you’re designing a wind turbine, you don’t want to loose all that energy to noise - it’d be a waste. Canny designers have made more efficient blades and  gear mechanisms which are a lot quieter.

As the Centre for Sustainable Energy argue, the research on people disturbed by wind power is pretty minimal, partly because the number of people who say they are continually disturbed is pretty small. Still, the research that has been done does suggest that wind farm noise isn’t any higher than normal background noise you’d get from other things around a house.

Being able to see the wind farm seems to make an impact, so it may well be a visual problem rather than an aural one. Interestingly, research on wind farms in the Netherlands  suggests that people are less likely to worry about the noise if they have a direct financial stake in the turbines.


Banner photo: Elliott Simpson

Are wind turbines expensive?

Onshore wind is the cheapest form of new electricity generation going. It’s just silly we’re not making more of it.

Weighing up the costs of different energy technologies can be a slippery business. Prices keep changing, and no new wind has been built in the UK for a while, so it's hard to get an accurate number.

People will give you a price, but they might not always include everything. You want to look out for something called “levelised cost of electricity” which takes into account stuff like upfront development expenses, debt finance, and how much it’ll take to operate and maintain the things.

Using that measure, the government's latest figures predict that the price of building new gas plants (currently the cheapest energy source) will go up quite a bit, while onshore wind costs continue to fall. They reckon onshore wind will be the cheapest energy source outright as early as next year. 

Other energy geeks are even more confident. Bloomberg New Energy Finance have done some calculations of their own. They reckon onshore wind is the cheapest new electricity source, bar none. They first said so over a year ago, and we know costs have come down since then.


Banner image: Graeme Maclean, creative commons

Do wind turbines kill birds?

If you’re worried about birds, you should be worried about climate change, not wind turbines. That’s one of the reasons the RSPB built a turbine at their HQ.

Wind turbines do kill birds. And bats. But before you swallow the Daily Mail’s claim that wind turbines kill 22 million birds a year, or Donald Trump’s line that wind power is killing ALL OF THE EAGLES, it’s worth doing some fact-checking.

The UK's first wind farm was built 25 years ago in Delabole, Cornwall. Founder Peter Edwards tells a wonderful story of Starlings flying by. "The sky went black with them, and they were heading directly for turbine, and I thought 'golly this is going to be carnage'."

But, the Starlings seemed to be weaving in and out of the turbines. When Peter went up to take a look, he found "there was not one dead bird underneath that turbine." 

There are electricity pylons near the Delabole wind farm. "What is interesting," says Peter, is "you find dead birds under the pylon wires continually”.

According to the Centre for Sustainable Energy, wind turbines are responsible for less than 0.01% of avian mortality caused by humans. It might be hard to hear, but British cats kill around 55 million birds a year. And that’s before we get into the other things we humans make - windows, roads, plyons, chicken nuggets, climate change...

For another comparison, a study in 2013 looked at birds in the USA and worked out that whereas wind farms killed 20,000 birds there in 2009, fossil fuelled power plants killed more than 14 million, and that, per unit of electricity generated, fossil fuels were 17 times more dangerous to birds than wind turbines (check out this ace Carbon Brief overview for deets).

According to the RSPB, wind turbines can harm birds in three possible ways – disturbance, habitat loss (both direct and/or indirect) and collision. We should be aware of all of these issues and make sure turbines aren’t built on big migration routes or on breeding and roosting sites.

The main point the RSPB stress, however, is that climate change is the biggest threat to birds, and wind is part of the the solution. The trick - which the Bat Conservation Trust would also argue - is to do wind well. For their own turbine, the RSPB did three years of breeding and wintering bird surveys as well as surveying bat populations to make sure they wouldn’t harm the wildlife in their nature reserve or local area. Scientists are continuing to research what causes bird and bat deaths and how we can best mitigate it.


Banner image: IIP Photo Archive, creative commons.