Insight: How green is the next frontier of wind power in Scotland?

The world's most powerful wind turbines at the European Offshore Wind Deployment Centre, better known as Aberdeen Bay. Picture: Vattenfall
The world's most powerful wind turbines at the European Offshore Wind Deployment Centre, better known as Aberdeen Bay. Picture: Vattenfall
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Climate crisis has put Scotland in the vanguard of renewable energy, but offshore innovation is also a threat to the environment, writes Ilona Amos

It’s impossible not to feel a sense of awe when you get up close to an offshore wind farm. Only then can you appreciate the true scale of the towering structures – in this case as tall as London’s BT Tower or three Scott Monuments stacked on top of each other.

But what was probably most surprising for me on my visit to Aberdeen Bay was the relative lack of noise. I had expected to hear a giant, rhythmic whomping sound and feel the turbulence as the rotors with a diameter of 164 metres chewed the air. It was all remarkably silent, save for the sea breeze, and strangely peaceful, hypnotic even.

The way things are moving such developments could soon become almost as familiar a sight as their land-based counterparts. Offshore wind is the next big thing for the UK, particularly Scotland. Not only does it produce renewable electricity, helping the country achieve its climate targets, it is opening up a whole new industry – and perhaps offering a kiss of life to one that has been anticipating the last rites.

With more than 6,000 miles of mainland coastline, Scotland has a lot of sea. And our much-cursed climate means we’ve also got plenty of wind. Globally the North Sea is considered one of the best places to build offshore wind farms because of its relatively shallow water and high wind speeds.

Scotland also has something else that gives us an advantage in the bid to build a thriving offshore wind sector – 50 years of expertise in undersea engineering, thanks to our oil and gas heritage. Add to that the country’s experience in onshore wind, which has been growing steadily and has matured over the past couple of decades.

All this together means Scotland can move swiftly to take advantage of its offshore potential.

What’s so good about offshore wind?

Offshore wind farms have the same green credentials as land-based turbines – they create renewable energy, do not consume water, do not emit environmental pollutants or greenhouse gases, while also providing a domestic energy source and creating jobs. Key advantages lie in the fact that offshore wind speeds tend to be faster and more consistent than on land, reducing energy intermittency associated with onshore turbines. Also being further away from human habitation means reduced visual impact and disturbance to local residents.

So where are we at?

Scotland currently has five operational offshore wind farms, mainly pilot schemes – including the world’s first floating offshore site – together amounting to more than 900 megawatts of installed capacity.

Scotland’s largest site, the Beatrice scheme, located off the Caithness coast, became fully operational this summer. With 84 turbines, it can generate a massive 588 megawatts of electricity – enough for 450,000 homes – and provides more than half of all the offshore wind generated in the UK.

There are a number of others in development, including four giant commercial projects in the Forth and Tay – 450MW Neart na Gaoithe, 784MW Inch Cape and 1,050MW Seagreen Alpha and Bravo, with up to 335 turbines between them.

The offshore wind sector is considered a UK success story, with the largest installed capacity in the world to date. Its contribution to annual generation increased from 0.8 per cent in 2010 to 6.2 per cent in 2017, and is expected to reach around 10 per cent by 2020. More than 7,000 people are already directly employed in the sector nationwide, and this is likely to increase.

So strong is the confidence in offshore wind, which has seen costs fall faster than anyone could have foreseen a decade ago, that Westminster has agreed a sector deal as part of the UK’s Industrial Strategy. This commitment aims to see offshore wind contributing up to 30 gigawatts of generating capacity by 2030.

Eight UK “clusters” have been formed under the sector deal, with two in Scotland – DeepWind, which covers northern and western Scotland, and Forth & Tay Offshore. The clusters are partnerships of industry, academia and the public sector, with the aim of developing a new offshore wind supply chain.

The Offshore Renewable Energy (ORE) Catapult, a technology innovation and research centre for offshore wind, wave and tidal energy, has been set up to support the emerging sector.

ORE Catapult’s Andrew Macdonald said: “Offshore wind is absolutely key to the future low-carbon economy. It’s a big opportunity for the North Sea and our job is to identify the challenges and help innovators through to market.”

What’s coming next?

Crown Estate Scotland, which manages leasing of the seabed out to 12 nautical miles and holds the rights to offshore renewable energy and carbon and gas storage out to 200 nautical miles from the coast, is poised to open up a new leasing round this autumn.

Potential sites are being outlined by Marine Scotland, but it’s likely there will be increased opportunity in deeper waters further offshore, reflecting advances in technology.

It marks the first major leasing round for commercial-scale offshore wind developments in Scotland. John Roberston, head of energy and infrastructure for Crown Estate Scotland, says the resulting contracts will allow developers certainty and better visibility for the future. He says there is recognition that the industry is maturing and the leases will help build an “efficient, long-term sustainable industry”.

So what’s not to like?

Donald Trump, whose Balmedie golf resort looks out at the Aberdeen Bay wind farm, warned the development would be a “monstrous” blight on the horizon. “I want to see the ocean. I do not want to see windmills,” he fumed. Then in 2011, after formal construction plans were submitted, the future president filed a complaint to the Scottish Government, bemoaning “the horrible idea of building ugly wind turbines directly off Aberdeen’s beautiful coastline”. The courts ruled against him.

But Trump is not the only one who has concerns over offshore wind. The RSPB, which is generally supportive of renewable energy, challenged plans to build four giant offshore schemes in the Forth and Tay. The conservation charity claimed thousands of protected seabirds would be at risk of death or displacement if the 300-odd turbines were erected, which could threaten the survival of species already in decline.

After a protracted legal battle judges found in favour of Scottish ministers and the projects are set to go ahead.

“Offshore wind has great potential for vast quantities of generation, specifically in Scottish waters,” said Charlie Nathan, senior conservation planner at RSPB Scotland. “But it comes with quite a considerable risk to marine wildlife, particularly seabirds, so we’re very keen for any action taken to combat climate change not to create any adverse effect or new environmental problem on biodiversity grounds. The projects we’ve seen come forward in Scotland have come with quite thorny issues around the scale of risk to internationally protected seabird populations up and down the east coast of Scotland.”

He believes there is a “legal and moral obligation” to look after Scotland’s world-renowned seabird heritage. “Studies point to very substantial impacts. Obviously we disagree with the decision around whether those levels of impacts are acceptable or not. What we’re seeing now is projects going ahead, even though it’s there in black and white the scale of impacts, with thousands of birds being killed annually or dying because they are being displaced from their foraging grounds.

“It gets even worse if there are several developments. Looking to the future, with vast amounts of offshore wind, there could be a situation where birds are no longer able to get to a lot of the best areas for feeding.”

Some of the key risks for other wildlife come around the construction phase. The impact of noise from piling for turbine foundations is known to displace marine mammals such as porpoises, dolphins and seals. There is also a potential risk to migratory species from underwater cabling, which gives off an electromagnetic field that could possibly disrupt their navigational abilities.

Conservationists are calling for some kind of offsetting scheme, that would require developers to invest in beneficial environmental projects to compensate for negative impacts.

Offshore wind could also spell bad news for fisheries, through both destruction of habitat and direct displacement of fishing fleets around offshore installations and undersea infrastructure. Fishermen are concerned their needs are being ignored as the industry takes off.

Malcolm Morrison, fisheries policy officer for the Scottish Fishermen’s Federation, said: “The fishing industry is not against offshore renewables per se, but we are focused on protecting our interests. We feel strongly that unlike when the oil and gas industry arrived in the North Sea in the early 1970s, the level of engagement with our sector from the renewables industry and from planners involved in assessing many of these projects has been unsatisfactory, and we want this to improve.”

He complains that plans have been published without any feedback sought from fishermen, then developers have shown unwillingness to make changes that would avoid problems. “Given the intense competition for space at sea, this could severely restrict fishing opportunities in the future,” he said.

The SFF believes wind farm owners should offer compensation payments for displacing vessels using mobile fishing gear, as has been done for some creelers. He added: “Proper, ongoing engagement with the fishing industry by all involved in the renewables planning process, coupled with the introduction of enforceable licence conditions which protect and recognise the importance of the fishing industry as a food producer, are necessary.”

How do we reduce the risks?

The 93.2MW Aberdeen Bay scheme – or to give it its official title, the European Offshore Wind Deployment Centre (EOWDC) – has been up and running for a full year. It currently hosts the world’s most powerful wind turbines, generating the equivalent of 70 per cent of Aberdeen’s domestic electricity demand – enough to supply 80,000 homes each year.

It was constructed using specially designed suction bucket foundations that require no piling to install, massively reducing noise pollution that can disrupt marine creatures. It is also running a pioneering £2.7 million scientific research programme to assess the environmental impacts of offshore wind, with in-depth scientific research and monitoring in a real-time environment.

Jesper Kyed Larsen, environmental expert for Vattenfall, which owns the EOWDC, said: “We are trying to better understand what is the actual impact of offshore wind farms on wildlife and the environment. Currently there is a lot of uncertainty when we are doing impact assessments for new projects over what the effects are on particular species or habitats.

“I’m leading an environmental research programme where we can proactively improve the evidence base for offshore wind projects and mitigation of impacts. We get together with other people from the industry, with regulators, environmental experts, NGOs and academia to identify the key knowledge gaps, where we can bring down this uncertainty, then we can have more realistic assessments and decisions on wind farms, including mitigation that can be adopted to manage impacts. We’re trying to take an active role in getting us there so we are not getting stuck in discussions about potential impacts that may be not real in the end.

“Animals don’t respect borders. It’s a big challenge to get international-level projects up and running. But as an industry we are at the scale of the North Sea so it’s really happening and it’s the way we need to move forward.”

So what might the future of offshore wind look like?

There are numerous intriguing innovations coming forward and many more still at the concept stage. Scotland is already making headlines in this department – the Hywind project, off Caithness, is the world’s first fully operational floating wind farm.

Coming soon to the UK for testing are supercharged turbines with a rotor diameter of 220m and output of 12 megawatts, to be installed at the ORE Catapult site in Northumberland. There are also proposals for vertical axis turbines and multi-turbine arrangements on a single pillar.

Vattenfall’s Kevin Jones, who oversees the EOWDC, is enthusiastic about the pioneering work his team is involved in. The scheme uses remote-controlled submarines for underwater maintenance and drones that are programmed to carry out aerial surveys of rotors and other hardware. Maintenance-free bolts, guaranteed to stay tight for 20 years, have been fitted to the turbines. A local thunderstorm warning system has been installed, as well as an erosion-safe mode for blades and online cable monitoring. Plans are also being developed to build artificial reefs around turbine bases, both to restore the underwater habitat and protect foundations and cabling from the effects of the sea.

Across the industry there is also an increasing interest in multipurpose schemes, with a wide range of possible combinations.

Andy McDonald is head of low carbon at Scottish Enterprise, which is involved with the clusters. He is confident that a move towards deep-water technology, such as floating turbines, could open up global opportunities for Scotland since many countries have very little shallow areas off their coasts. He also points to new collaborations that might once have seemed unthinkable, as a growing number of petroleum giants move into renewables.

“It’s a logical progression for the oil and gas industry,” he said. “The energy sector is transitioning and they are already looking at what their role will be. They have a great deal of expertise in offshore energy and undersea engineering and a huge amount of infrastructure in the North Sea, so there are a number of things they can bring to the table in the transition to low-carbon and renewables. The industry has 50 years of experience of work in a very challenging environment.”

McDonald says there is currently a lot of discussion over potential repurposing of drilling platforms and subsea cabling, much of which is due for decommissioning in the near future, for use in the renewables sector. “It’s a huge economic opportunity for Scotland,” he said.

Offshore wind farms could also soon be used to power oil and gas platforms to remove the need for diesel generators and cut their carbon emissions. Other ideas include integration of offshore wind with floating solar farms, wave energy devices or even shellfish farms.

“It’s something we’re looking into with interest,” said Vattenfall’s Jesper Kyed Larsen. “It has been an ongoing discussion for many years, whether there could be co-use of offshore wind farms. Unfortunately it’s not as simple as it may sound in terms of operating the wind farms and being able to have the kind of vessels we need and unhindered access, but we are investigating and trying to get ahead of any opportunity it could present for specific projects.”

All this and more is set to be discussed by the industry’s top players at the 2019 Floating Offshore Wind conference and exhibition, which is being held in Aberdeen on 31 October