Clean energy isn't always green energy. That's the case in Scotland where some wind farms are built on peat bogs. Peat stores a lot of carbon, which is released into the atmosphere when turbines are built. From Radio Deutsche Welle, Peter Shevlin reports how scientists are assessing the environmental benefits and trade-offs of building windfarms on peat.
GELLERMAN: Scotland is the windiest country in Europe and a proposed network of wind farms plays a pivotal role in the country’s energy future. Scotland wants to go all-renewable by 2020. But the plan faces stiff opposition in part from ‘The Donald’.
Billionaire Donald Trump recently testified before Scotland’s parliament, saying proposals to erect wind turbines, on shore and off, would interfere with his new showcase golf resort and play havoc with Scotland’s future.
TRUMP: They are so unattractive, so ugly, so noisy and so dangerous that if Scotland does this I think Scotland will be in serious trouble, I think you'll lose your tourism industry to Ireland and lots of other places that are laughing at what Scotland's doing.
GELLERMAN: And then there are some Scots who oppose building wind turbines - for peat’s sake. Seems putting the turbines on peat bogs which store huge amounts of CO2 could dry the bogs, releasing more climate changing gas into the air than the wind turbines would save.
Reporter Peter Shevlin visited Europe’s largest wind farm in Scotland where they’re testing a new tool to measure peat’s carbon footprint. And he prepared this story for Radio Deutsche Welle.
SHELVIN: With 140 turbines generating up to 322 megawatts of electricity, powering up to 180,000 homes, this, you might think, is clean, green energy at its best. But because this wind farm and many others are built on peatlands, they are not completely free of carbon emissions. Peatland is nature’s way of storing CO2 and disturbing it releases this locked up carbon and kicks off the decomposition of the organic matter.
We are only beginning to understand the development of wind farms on these carbon-rich habitats. Biologist Dr. Simon Drew from Stirling University has been studying how carbon is lost during wind farm construction. And to do this, you have to analyze the water running off the wind farm into surrounding streams.
[SOUND OF WATER TRICKLING]
DREW: So, we’re in a catchment, just outside the Whitelee Wind Farm, that drains it, about 14 miles south of Glasgow. We’ve got a device in the stream here, which is measuring dissolved organic carbon in the water. And it takes those measurements and stores it on the machine.
SHELVIN: So, you’re looking at dissolved organic carbon. For the layman, what does that mean?
DREW: That’s the fraction of carbon, which is produced when peat rots and it is washed out into the stream. In a lot of these upland areas, you’ll see that the water is quite highly colored, it’s dark brown or blackish and it’s that material which gives the water its color.
SHELVIN: Peatland covers roughly 15 percent of the UK and holds about 2,300 megatons of carbon. Losing just five percent of this peatland would be the equivalent of about a year's worth of UK’s CO2 production escaping into the atmosphere. University of Stirling’s River Science expert, Professor Dave Gilvear, was one of the first to discover the carbon impacts of wind farm development, so I drove north of Glasgow to find out more.
GILVEAR: Four or five years ago, at a wind farm site, close to Stirling here, we monitored dissolved organic carbon lost from it and found that the loadings and the concentrations were much higher than controlled catchments and controlled streams on either side, suggesting that the presence of the wind farm was resulting in loss of carbon from the peatlands.
SHELVIN: This early study of four or five years ago, has it helped to plan windfarms now?
GILVEAR: I think it has. We’ve also been monitoring another wind farm down in Ayrshire - we’re not finding the same results there, in that best practice methods of construction are being adhered to. The Brazer Dune site is now seen as sort of poor practice. And hopefully those sorts of construction won’t be happening again.
SHELVIN: This research into the environmental impact of renewable energy means that there needs to be an alternative way to analyze the wider effects of developing these resources. Professor Dave Gilvear:
GILVEAR: I think most people understand what renewable energy is: it’s getting power from the sun, it’s getting power from water, it’s getting power from the wind. But that doesn’t necessarily mean that it’s green in that the construction of a wind farm, the construction of a hydropower station is going to have an environmental impact, so, if you put a dam across a river, for example, and you don’t have a fish pass built into it, it’s going to stop the migration of fish and that’s an environmental impact.
And in that case you would argue that hydropower is not green but it is renewable and so I think that distinction is an important thing to realize when you’re looking at whatever type of energy production it is whether it’s hydro, wind or solar.
SHELVIN: To help quantify the carbon footprint of wind farms a new tool seems to be making a huge different to wind farm developers. The carbon payback calculator gives companies a way to estimate how long it would take for a wind farm to pay back the carbon it released from building it. Dr. Drew gave me the low-down.
[SOUND OF RUNNING WATER]
DREW: The carbon payback calculator for wind farms on peatland was produced in 2008, and it was a project commissioned by the Scottish government and carried out by a research group at Aberdeen University. In planning and iniating a wind farm, you have all sorts of carbon costs.
You need to produce the turbines and get them in place, and if they’re on peat, you destroy quite a lot of that peat and the carbon that’s in it by creating the roads and digging it all out for the turbine bases and so on. The idea was to get all of those costs and weigh them against the carbon saving produced by the wind farm over the course of its lifetime.
The initial estimates that this group came up with, I think were kind of between three and 30 years. Now the operational lifetime of a wind farm is about 25 years, so potentially, although you have a sort of non-fossil fuel energy source, it’s not carbon neutral if it’s going to be for that long.
They just completed an update for that calculator and refined some of the parameters for it and it’s now believed that most wind farms will be, their payback time will be towards the bottom end of that estimate, so three to five years, probably even a lot less in some cases, depending on how well the site is managed.
[SOUND OF RUNNING WATER]
SHELVIN: So the calculator has basically said it’s worth having a wind farm.
DREW: In terms of carbon, yeah although you still get people objecting on visual grounds.
SHELVIN: Back on Whitelee wind farm with the turbines piercing 100 meters, you have to make up your own mind about the visual impacts. But the impact on the peatlands is clear, as is the lost carbon.
[SOUND OF FOOTSTEPS]
DREW: There’s different ways that carbon is lost. It’s lost directly when they dig out the peat to put the bases for the turbines in, usually these are concrete bases and they have to remove a large amount of peat to do that.
And that peat gets put in, generally, is put in these features call borrow pits. So the road that we’re walking on is made from rock that’s ground up hardcore and it’d be quarried locally, somewhere. And the quarry that they create to make this road will be backfilled with all the peat from the turbine bases, so a lot of it is just lost directly as peat.
Also, the pads for the cranes that put these huge, these huge turbines in, and there also might be bits of drainage that are put in locally. So there is peat and carbon that’s lost through all these different ways.
SHELVIN: But these different ways in which carbon is lost, what is more important? The preservation of peatland habitat or the ongoing supply of renewable energy through wind power? Professor Dave Gilvear, again:
GILVEAR: I think that wind energy in Scotland is a short-term solution to our renewables obligations and that somewhere down the line, you know, we’ll be moving to offshore energy, for example.
And then we’ll have this sort of environmental legacy of the impact of these wind farms on what was, prior to that, sort of relatively wilderness pristine kind of landscape. So if you take a long-term perspective on it, it’s perhaps not the best idea, but in the short-term, it is meeting our need for renewables.
It’s very difficult if you destroy a peatland to bring it back. There are restoration methods, but they’re never going to bring back a purely, naturally functioning peatland system.
SHELVIN: It seems that there is an environmental tradeoff happening in Scotland. While the impact of development on peatlands is leading to carbon loss, the green energy generated from wind farms means that the country will be less reliant on fossil fuels in the future. Peter Shevlin, Glasgow.
[SOUNDS OF STREAM RUNNING]
GELLERMAN: Our story on Scotland’s wind farms comes to us by way of Radio Deutsche Welle show: Living Planet.
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