As we become ever more accomplished at harnessing the power of renewable sources for use as energy, there’s one issue that needs to be confronted – how to store energy so that it can be used at a later date. In Orkney, the craggy and beautiful archipelago off the northeast coast of Scotland, an EU-funded project called BIG HIT is doing just that, by converting excess energy from wind turbines on the islands of Eday and Shapinsay into hydrogen.

Orkney is blessed with plenty of wind. Its blustery climate allows residents to source 100 per cent of their annual energy from renewables-backed electricity. In fact, it is so successful that it frequently generates more power than the local population can use, and more than the UK National Grid can handle. In the past this has meant that wind turbines, many of which are community-owned, have had to be turned off. As a result, Orkney’s turbines have typically lost up to a third of their annual output.

Losing energy in this way is far from an isolated problem. According to Nigel Holmes, chief executive of the Scottish Hydrogen & Fuel Cell Association, a BIG HIT partner, around 1.5 terawatt hours (equal to one trillion watt-hours) of electricity generated from wind power were lost in the UK in 2016, leading to £150m being paid in compensation to the owners of wind turbines which had to be turned off. In December 2018, The Scotsman reported that over the past eight years, £500m of taxpayers’ money has been paid to wind farms for the same reason. ‘It’s costing us and we’re losing resources that could be used more efficiently,’ says Holmes. ‘This is absolutely where hydrogen has a very complementary role to play.’

The project in Orkney uses electrolysis of water to convert excess wind energy into hydrogen close to the point of production. The hydrogen is compressed and stored in high-pressure cylinders for onward transport in specialised trailers. It is then shipped to Orkney’s capital, Kirkwall, where it provides fuel for a fleet of vans and to ships docked at the harbour, allowing them to turn their engines off and reduce pollution and diesel emissions. The next project, already under way, will convert the ferry that runs between Kirkwall and the island of Shapinsay to run partly on hydrogen, a ferry that will eventually be replaced with a zero-emission, fully hydrogen-based alternative.

‘About five years ago this would have been a very theoretical discussion about how we can take constrained hydrogen and make better use of it,’ says Holmes. ‘We’re now at the point where things are actually starting to happen.’ The work in the Orkney islands compliments similar projects currently taking place on the continent, in particular in Denmark and Norway where a number of passenger ferries have been converted to run on hydrogen and where hydrogen storage projects are now being scaled up. ‘The Orkney project is showing how this can happen at a local level,’ adds Holmes. ‘It is invaluable in helping us to understand how the energy system in Scotland, the UK and elsewhere may need to evolve as we go forward with more renewables.’

 This was published in the May 2019 edition of Geographical magazine

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