Wind power is one of the most cost-effective, fastest growing and arguably underused sources of energy currently available to us. It’s also perceived as one of the greenest because wind turbines don’t produce any greenhouse gases or pollutants while in operation. But that’s the rub: when they’re not in operation — meaning, getting them in the ground and working out what to do with them once they’re taken down — they do have an environmental impact.
With wind power adoption on the rise and turbines popping up along our coastlines and open spaces, what are the environmental impacts? In the grand scheme of things, how bad are they and is there anything we can do to mitigate it?
It’s not too difficult to see why wind power is one of the most popular methods of energy generation and has been for centuries. As long as there’s enough wind to make them turn, turbines can be installed more or less anywhere there’s a bit of free space — from fields and mountain ranges to way out at sea — making them ideal for both large economies trying to decarbonize, as well as remote communities needing an easy source of power.
They’re simple to maintain and should last for decades; they’re cheap to run, and their footprint is actually relatively small despite their size1. According to a survey of large-scale wind farms by the National Renewable Energy Laboratory in the United States, which has the highest wind power capacity in the world behind China2, less than one acre per megawatt of power output capacity is disturbed permanently and less than 3.5 acres per megawatt are temporarily disturbed during construction3. Costs are also coming down all the time with many governments now offering incentives to encourage more uptake4.
Although it doesn’t produce as much power as some other sources — responsible for around 5% of global electricity produced in 20185 — wind offers tremendous potential, particularly when deployed offshore, which is where a lot of the focus is at the moment. Although offshore wind only accounts for around 0.3% of total energy generation worldwide, it’s capable of making a much bigger contribution.
According to the International Energy Agency, or IEA, if we built wind farms on all of the usable offshore sites worldwide sticking to certain conditions — that is, no further than 60km off the coast and in waters no deeper than 60m — they could generate more than the world’s entire current electricity demand on their own6. But this would mean huge swathes of wind turbines popping up on practically every spare stretch on our coastlines, and would we want that? Probably not, but it does show what we could do with wind power if we really went all-out with the technology.
And while a world completely scattered with turbines in every suitable spot may ultimately solve our clean energy problem, what we often forget is the amount of work required to put them there in the first place — both offshore and onshore — and this is where some of the arguments against wind’s green credentials comes into play.
So, what are we talking about? Well, there’s a lot that goes into preparing the ground for the turbines, excavating for the foundations, bringing all the components to the site, a lot of concrete is typically needed, onshore farms will often need new service roads to be put in, and the list goes on. Plus, a lot of these jobs are done using diesel-powered machines.
To give an example, the world’s largest offshore wind farm is now under construction off the coast of the UK, which promises to produce enough electricity to power around 4.5 million homes, or approximately five percent of the country’s total electricity demand, using the world’s most powerful turbines. This all sounds great, but it also means miles of cabling, converter stations, vegetation clearance, land drainage, roads, grid connections etc.7
And with onshore farms, despite that relatively small footprint that we talked about earlier, there’s still little else that you can do with the land between the turbines other than farming and grazing. When there’s often little choice but to build these huge structures in rural areas, you can begin to see why people talk about the “industrialization of the countryside8.”
Wind’s environmental impact has also been called into question in other ways. There have been complaints from some people who live or work near wind farms about the noise the turbines make. In other places, birds and bats have been discovered unwittingly flying into them, and this is thought to have contributed to a noticeable decline in the numbers of certain species. In the US alone, it’s estimated that as many as half a million birds are killed in wind turbine collisions each year, and with wind energy capacity due to increase significantly in the coming years, this figure could reach almost one and a half million a year9.
But, things are never that simple. While the skies may be suffering, there’s also evidence that offshore wind farms can be a boon to ocean species. A study by Kaela Slavik at the Helmholtz Centre for Materials and Coastal Research in Germany found that the underwater platforms are having an unexpected and beneficial benefit to blue mussels. A typical wind turbine can support about four metric tons of the shellfish. And they also act as a marine preservation area since fishing and bottom trawling isn’t allowed for safety reasons. Essentially, they’re creating sanctuaries for sea life.10 The offshore wind farm near Block Island in the U.S. is seeing similar wildlife flourishing around the base of the turbines.11
Despite some negatives, generally the world’s public tends to lean in favor of more renewable energy technologies to fight climate change, including wind power, just as long as those turbines aren’t built anywhere near where they live. The trouble is, with onshore farms in heavily populated countries, it can be difficult to avoid people entirely, especially when they’re not afraid to put up some resistance. In Germany, installations have declined sharply due to lack of suitable land and a rise in people successfully campaigning against plans to build turbines in their area, and it’s dealt a blow to their carbon reduction plans12.
Another dilemma is what to do with the turbines once they come to the end of their lifetimes. How exactly do you dispose of these structures when they can be as big as a skyscraper, and there might be hundreds of them on a single farm? The good news is that around 85% of a wind turbine’s components can be recycled or reused13, from the copper wiring and electronics to the gearing mechanisms, but the same can’t really be said for the blades, which are usually made from composite materials such as fiberglass or carbon fiber, depending on their age.
These materials are strong enough to withstand the extreme weather conditions that turbines are often subjected to, and light enough so the turbines can actually turn, but when they need to be decommissioned there’s little else you can do but bury them in landfill sites or burn them through a process called pyrolysis.
The landfill option is obviously not very eco-friendly, especially when the blades can be longer than the wing of a Boeing 747 and weigh up to eight tons each. This means they often have to be transported one at a time, and that’s a lot of truck journeys, plus there’s all the heavy machinery needed to cut up the blades before they’re buried.
With pyrolysis, the blades are also chopped up, but then they’re placed into high-temperature ovens to break down the composite fibers. This creates a material that can be used to make things such as paints and glues. But the process requires a lot of energy, so even though it can be thought of as a form of recycling, it’s still not all that green14.
All of this is a big issue at the moment because the turbines that were installed in the wind power boom period of the 1990s and 2000s are now coming to the end of their lifecycles or are already there15. It is likely only going to get worse in the future too, as installations of wind turbines worldwide has increased by more than five times over the past decade, so unless we come up with new ways of getting rid of them, we’re going to have an even bigger landfill problem further down the line16.
In that case then, maybe we should start thinking about making turbines from something else? Windmills — what wind turbines evolved from — where historically composed of wood and other sustainable materials and it wasn’t until the 1980s that composites became the standard choice.
We’re now seeing incredible things being done with high-strength wood in the construction sector, such as huge tower blocks and even some of the venues for the Tokyo Olympics, and some believe we should be looking at wood again for wind power. In Sweden they have just built the world’s first wooden wind turbine tower and plans are in place to scale this up in the future17.
In fact, there’s a lot going on to repair some of the damage to wind power’s reputation as a green energy source. For starters, it appears there may be an alternative to burying or burning those used turbine parts after all. Washington-based Global Fiberglass Solutions has found a way of grinding up large pieces of plastic composites into tiny pellets, which can then be used in construction and manufacturing18.
For those newer blades, a company called Carbon Fiber Recycling has found a way to recycle carbon fiber waste, which was actually tested on wind turbines when they were doing their research. Their process separates the carbon fiber from the epoxy resin that is also used to make the blades. The carbon fiber is then chopped up into a form where it can then be used in a number of different industries and the resin is turned into a fuel that goes back into powering the company’s machines, so nothing ends up in landfills19.
In the Netherlands, they’re recycling in a different way. They have been using decommissioned blades to make slides, tunnels and ramps for children’s playgrounds, as well as bus stops and public seating, while in Denmark plans have been submitted to build a bridge out of composite materials that were once part of a turbine8.
Elsewhere in Europe, a consortium of wind and chemical industry bodies has come up with a way of turning used fiberglass blades into a material that can be used in cement production, reducing typical CO2 emissions by around 16%. The blades have to be broken up into tiny bits first, but this can be done at the site where the turbines were installed, so there’s no need for any of that heavy transport20.
And in Poland, an urban tech start-up has pioneered a new approach to wind power by building panels made up of vertical rows of small turbines. Although more suitable to smaller applications rather than powering huge grids, they are designed to eliminate the main disadvantages of wind power by being silent, quick and easy to set up without being a danger to wildlife or making a huge impact on the environment21.
It’s important to remember that we’ll never have a 100% green source of energy. There will always be some kind of environmental impact no matter what we do. Even with it’s current downsides, if you look at the life cycle cost analysis (LCA) of different forms of energy generation, wind turbines are only beat out by hydro power.22 23 24 25 So, yes, maybe wind power does come with more downsides than many of us first realized. But the impact of increased investment in this source of energy — at a time we urgently need to lower carbon emissions — is undeniable. Imagine how much better we can make that LCA with the innovations and new approaches to materials and disposal going on right now?
- US Energy Information Association ↩︎
- Power Technology – The top 10 countries in the world by wind energy capacity ↩︎
- Union of Concerned Scientists – Environmental Impacts of Wind Power ↩︎
- Clean Energy Ideas – Advantages & Disadvantages of Wind Energy ↩︎
- Center for Climate and Energy Solutions – Renewable Energy ↩︎
- The Guardian – Offshore windfarms ‘can provide more electricity than the world needs’ ↩︎
- The Engineer – Onshore work begins for Dogger Bank Wind Farms ↩︎
- Wikipedia – Environmental impact of wind power ↩︎
- US Fish & Wildlife Service – Wind Turbines ↩︎
- MIT Technology Review – First Evidence That Offshore Wind Farms Are Changing the Oceans ↩︎
- The Press of Atlantic City – Nation’s first wind farm creates fishing, tourism hot spot ↩︎
- Financial Times – Germans fall out of love with wind power ↩︎
- Evwind – Strategies for the recycling of wind turbine blades ↩︎
- ESS Utility Consultants – Green energy: wind power’s recycling dilemma ↩︎
- BBC – What happens to all the old wind turbines? ↩︎
- Fortune – The latest landfill problem comes from the renewable energy industry ↩︎
- Electrek – Sweden erects the first wooden wind turbine tower ↩︎
- Global Fiberglass Solutions Becomes the First US-Based Company to Commercially Recycle Wind Turbine Blades into Viable Products ↩︎
- Wind Power Engineering Development – Tennessee carbon fiber recycling outfit can recycle 100% of wind turbine blades ↩︎
- Composites World – Decommissioned wind turbine blades used for cement co-processing ↩︎
- Emerging Europe – Wind Panel, the Polish start-up that wants to make wind energy cheaper and more effective ↩︎
- Renewable Energy: Wind Power – Life Cycle Assessment of a Wind Turbine ↩︎
- National Renewable Energy Laboratory – OpenEI ↩︎
- U.S. Department of Energy – Advantages and Challenges of Wind Energy ↩︎
- Ars Technica – Wind power prices now lower than the cost of natural gas ↩︎