The first renewable energy scheme in Scotland to draw heat from the sea could be installed in Shetland later this year.
The archipelago's capital of Lerwick is already host to the largest district heating scheme in Scotland which allows 1100 homes as well as 100 industrial and public buildings to be heated by means of a pipe which circulates hot water around the UK's most northerly town.
The system is currently heated by burning the islands' household and industrial rubbish. The plan is to meet growing demand for connections to the system by adding an extra source of heat through the extraction of heat from the seawater in Lerwick harbour.
The project was devised because, despite importing rubbish from neighbouring Orkney as well as from the Highlands, the sparse population of the north of Scotland means that there is insufficient waste to burn to meet demand from the town's district heating system.
The current waste-to-heat system burns around 22,000 tonnes of waste each year to supply around half the heat demand of Lerwick's households and businesses.
Shetland Heat Energy & Power Ltd (SHEAP) is currently in discussion with the Glasgow-based heat pump manufacturer Star Renewable Energy about the project and a final decision about whether to press ahead with the project is expected to be made later this month.
Star Renewable Energy's director David Pearson said that seawater from Lerwick harbour is already extracted to cool Shetland's diesel-fuelled power station. The seawater-to-heat project will either use this water source or pump ashore seawater from elsewhere in the harbour.
In order for the project to take advantage of the government-funded Renewable Heat Incentive subsidy scheme, Pearson says that the project will not be allowed to use the hot water effluent (the hot water produced by cooling) from Lerwick power station as the rules stipulate that no industrial sources of heat can be used.
Instead fresh seawater would be cooled down from around eight to four degrees, harnessing enough energy to add a further 2MW of capacity to the town's 6.3MW district heating scheme.
"We are an industrial refrigeration company and have already installed refrigeration systems in the nearby Shetland Catch fish plant," Pearson said. "With this project instead of the heat from the refrigeration process being thrown away we would capture the heat from the seawater and use it."
The revolutionary technology has been successfully installed in lakes, rivers and estuaries in Scandinavia and Japan and was separately pioneered by Star Renewable Energy when it installed a 14-megawatt seawater based heat pump in the fjord next to the Norwegian town of Drammen in 2011.
Steven Peterson, operations managers of Shetland Heat Energy and Power, said that going ahead with the project would allow Lerwick's district heating scheme to reduce its reliance on oil, which is used to top up the system's supply of heat during peak periods.
The project would also reduce carbon dioxide emissions by allowing more homes and non-domestic properties in Lerwick to get away from oil-fired and electric heating.
Peterson added that, as it is cheaper to heat buildings using district heating than with conventional central heating systems, there is currently a two-year waiting list to be connected to the Lerwick district heating scheme.
Adding capacity by using heat from seawater would allow around 200 extra households in Lerwick to be connected to the district heating scheme.
�¢ A scheme to heat the University of Glasgow by drawing heat from the River Clyde has been put on hold as one of the main sources of funding for the proposed scheme insisted that all construction work be completed within twelve months. A university spokesman said that a feasibility study into the scheme, completed earlier this year, had found that it was technically possible but that, given the engineering challenges of the project and the time needed to obtain consents, the decision had been taken not to press ahead for the time being while the university completed a rebuild of its district heating system.
"The ongoing district heating project has been adapted to ensure that the potential to connect a heat pump at a later stage can be realised," the spokesman said.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article