The UK gets plenty of wind, but the challenge lies in storing this energy (Image: Robbie Shone/Aurora)
To go green, the UK will need to make the most of wind power. Teams of engineers are racing to do just that
WE’VE got six years. By 2020, 20 per cent of the UK’s energy should come from renewable sources, to meet the terms of a European Union agreement. It is likely that most of that energy will come from wind, which the UK gets plenty of. The challenge is working out how best to store the power.
There are about 4500 wind turbines on the UK mainland, which together have the capacity to produce about 7.5 gigawatts of electricity, enough to power about 4.3 million homes. But wind is flighty, and doesn’t respond to fluctuations in energy demand, so the tricky part is keeping that energy for when it’s needed. Luckily, teams of engineers are on the case.
Mechanical engineer Seamus Garvey, for one, has a few ideas up his sleeve. A professor of dynamics at the University of Nottingham, Garvey remembers the moment one wild idea popped into his mind. Driving along the motorway, he thought to himself, why not store excess energy underwater?
In principle, the electricity a wind turbine produces can be used to suck in and compress air. This air can be stored for a time before the pressure is vented to drive a generator, turning the stored energy back into electricity.
Garvey’s idea was to store the compressed air in fabric bags at the bottom of the ocean. “I couldn’t shake the thought of it, so I set out to prove it was a bad idea.” But it wasn’t such a bad idea after all.
Keeping air compressed means applying a huge amount of pressure – something that’s in plentiful supply deep under the sea. “It’s important to take advantage of the stuff around you,” says Garvey, who is now developing a commercial underwater compressed air storage system with a Canadian company.
The bags of air could also be stored in underground coal and salt mines, especially considering the UK has plenty of these currently lying unused. “Abandoned shafts make a very nice pressure vessel,” says Garvey.
Business in batteries
Other teams are taking a more traditional approach to storing energy: with batteries. Such batteries would need to store enough electricity to power the country, and be able to respond to electricity demands that fluctuate by the second. This leaves a lot of interesting problems to be solved.
At global energy company AES, Marek Kubik is helping to develop one of the largest-scale lithium-ion battery projects in the UK. As a business strategy adviser, Kubik’s role is varied. “One day I’m out meeting stakeholders, the next I’m putting together a grant funding proposal and yet another I’m assessing a potential project or looking for investments,” he says. Kubik is also a visiting fellow at the University of Reading, where he is investigating how the development of renewable energy sources will affect the market for fossil fuels.
Kubik enjoys taking a broader look at the role that innovative technologies play in renewable energy. He spends a lot of time speaking to policy-makers and industry stakeholders, so has a hand in steering the development of the industry as a whole, he says. But there are exciting jobs to be found at the cutting edge of battery technology too, says Emma Kendrick, chief technologist for energy storage at electronics company Sharp.
Kendrick is developing batteries that use sodium instead of lithium. Because sodium is the more abundant of the two elements, such batteries may be cheaper than their lithium-ion counterparts, says Kendrick. She also manages other research and development projects undertaken by teams at Sharp. “I love discovering fundamental science that complements the development of technology,” she says.
Kendrick, a chemist, and Kubik, an engineer, both did industry-funded PhDs, which are a good way into an industry career, say the pair.
Andy Gregory took a different approach. After earning his degree in civil and structural engineering, he moved straight into a civil engineering role. Now he works at energy utility company Scottish and Southern Energy developing another technique of storing wind power: pumped hydropower.
This technology makes use of gravity to store energy. Electricity is used to pump water up a hill where it is stored in a reservoir. When there’s a demand for electricity, the water is released to flow down the hill, turning turbines to run a generator. It is a technique that has been used in the UK since 1963.
It’s not difficult to be enthusiastic about your job when you work in the highlands of Scotland, says Gregory, who is based near Fort William. But even more than the scenic countryside, Gregory enjoys working on a project that aims to provide enough power for more than 1 million homes.
“I get to spend time outdoors in the highlands of Scotland and get paid for it, along with the experience of working on what is a one-off project for the UK with worldwide experts in the field,” he says.
A diverse team of people is vital for his and other pumped hydropower storage projects, says Gregory. Civil, mechanical and electrical engineers design and build the projects, while ecologists and planners organise funding and oversee development. “It’s all about building a team of people with complementary skills and the ability to work together,” he says.
Now that the energy industry is turning to renewable sources of power, the possibilities are bountiful. From underwater storage bags to advanced batteries, the solutions are as varied as the career opportunities for the people behind the developments.
Case study: Energy entrepreneur
Storing the energy that wind turbines produce is no easy task (see main feature). Many energy companies employ consultants to help develop technologies that solve such fiendish problems. But if you’ve got good ideas, why not try them out yourself?
That was Mark Howitt’s thinking. Howitt decided to leave his consultancy job and start a company with his friend Jeff Draper, a fellow physics graduate. Together, the pair explore, develop and hope to sell their own ideas for energy storage technologies through their UK company Storelectric.
Innovation can strike at any moment, says Howitt. “One idea first came to me on my morning jog,” he says. While gazing at the Mersey estuary, Howitt realised that a salt basin on the other side of the river would be a perfect place to stash compressed air, which is used to store wind power.
As the only two members of their company, Howitt and Draper share a range of responsibilities, from developing and patenting ideas to securing funding and investment. “Raising funds is the most challenging part,” says Howitt. Although many of the pair’s applications are successful, and they were finalists in a recent Clean and Cool competition run by the International Festival for Business, their funding application to the UK Department of Energy and Climate Change was recently rejected for “not being innovative enough”.
But Howitt perseveres, because he is passionate about renewable energy. “It’s the big industry of the future,” he says.
This article appeared in print under the headline “Bottling the wind”
Article amended on 7 November 2014
When this article was first published, it misstated the date when pumped hydropower was first used in the UK.
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