Dunbar plans to convert seaweed into energy

Dunbar has a plentiful supply of seaweed. Picture: Ian Georgeson
Dunbar has a plentiful supply of seaweed. Picture: Ian Georgeson
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HUNDREDS of tonnes of seaweed cast on to an East Lothian beach each year could be converted into renewable bio-fuel.

Experts say Dunbar’s plentiful supply of seaweed is a potential gold mine and hope a new plan to harness it as a sustainable fuel could see kelp catapult the area into the green power big league.

A study, supported by Glasgow Caledonia University, would see 500 tonnes of kelp transformed into a raw material for an anaerobic digester that could initially power around 20 homes.

Coastal residents have long complained about the deluge of seaweed on East Beach – which emits a foul stench as it decomposes and provides a breeding ground for swarms of sandflies.

The plans, thought to be unique in world science, have been described as a “win/win” for Dunbar by “converting what is currently a costly pollutant into a commercial opportunity for the town”.

Driven by Dunbar Shore and Harbour Neighbourhood Group (DSHNG), Dunbar Marine Resources Ltd, and Dr Alastair Sutherland of Glasgow Caledonian University, it is hoped a small-scale scheme – that would require investment worth £250,000 – could be launched as early as next year.

Dr Sutherland said the project could convert a “pollutant into an asset”. He said: “The technology for anaerobic digestion is well established but no-one is doing this with seaweed, which is a novel process that I have been investigating for the last four years. It’s been proven to work at laboratory scale and now we want to take it to a commercial level.”

The senior lecturer in microbiology said the long-term aim would be to harvest seaweed for conversion rather than relying solely on beached kelp.

Dunbar resident Cian McHugh, who lives near the beach and is one of those involved in the scheme, said East Beach was an ideal location with its ready-made supply of kelp. He said: “Anaerobic digestion [AD] is a continuous process – you cannot stop it or the whole thing grinds to a halt. You have got to have a continuous supply of seaweed but it only comes in once or twice a year.”

AD is a long-established method of producing methane bio-fuel from a feedstock, which is then used to generate heat and power or as a transport fuel. It takes place in sealed containers so there is no smell or release of methane gas.

Alasdair Swan, from DSHNG, is working closely with the local authority to limit the damage caused by seaweed on the beach.

A feasibility study lasting three to six months has been launched into the project.

Mr McHugh said: “At the moment, the seaweed is spread as fertiliser. You get that value but the problem is when it decomposes as it releases methane – a very damaging gas.

“Our process captures it and uses it for something useful. It’s creating green energy and you don’t have pollution damage when it is spread. You also capture and use it as a bio-fuel; that’s one of the major benefits of it. You capture the methane and make bio-fuel, you have fertiliser and you have got potential antioxidants.”

If the study is successful, it could then move on to looking for a suitable site for an anaerobic digester.

Seaweed has long been mooted as a sustainable bio-fuel – with a number of Scottish projects racing to crack the big time. The salty marine plant could also solve a potential future world food shortage.