Seaweed "efficient and reliable" biomass fuel, claim researchers
Tuesday 28 October 2008
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| Seaweed could be harvested and put through an anaerobic digester to produce biogas, the researchers said |
Researchers at the Scottish Association for Marine Science (SAMS) have hailed seaweed as a possible feedstock for biomass energy production.
In a report commissioned by the Crown Estate, they have recommended seaweed for use in heat and transport energy, and have recommended the creation of a small-scale commercial farm in Scotland.
In the Marine Estate Research report, the Association said that marine algae, specifically seaweed, has already been proven by US researchers as being "as good" as conventional biomass feedstock grown on land.
And the seaweed feedstock, which could be used in an anaerobic digester to produce methane gas, could sidestep many of the problems associated with conventional biofuels, as it is grown in seawater rather than arable land, and it does not use limited freshwater supplies.
"Efficient and reliable"
The SAMS document also reported that seaweed demonstrates high conversion efficiencies and a good conversion rate, and that Scotland is ideally placed to generate seaweed-powered electricity.
Professor Mike Cowling, science and research manager at The Crown Estate, said: "Given Scotland's rugged western coastline and island groups, and relatively clean seas, it is sensible to examine the farming of seaweeds and sustainable harvesting of natural supplies as a source of energy, to heat our homes and fuel our vehicles. Heating and transport make up around three quarters of our energy use so it's vital that we find new ways of meeting that demand.
"Extracting energy from seaweed is a particularly efficient and reliable method of producing green energy, and the growing of seaweed could have positive impact on local marine biodiversity. Crucially, using seaweed as a source of biomass avoids the problems associated with agricultural crop biofuels such as pressure on supplies of arable land and fresh water," he added.
Biodiversity
According to SAMS, the residue from the anaerobic digester can be used as nutrient supplements for agriculture.
Furthermore, it reports that farming the marine algae could have a positive impact on biodiversity, attracting wildlife and slowing eutrophication, the process by which an excess of nutrients in seawater causes a shortage of oxygen and damages its ecosystem.
It has to be accepted that a larger portion of the seas will be farmed
The report stated: "If marine biomass is a serious contender for supplying even a small percentage of our energy needs and if these seaweeds are to be cultured, rather than harvested from the wild, then it has to be accepted that a larger portion of the seas will be farmed.
"While culture operations must be subject to their own environmental impact assessment, seaweed farms offer the possibility of increasing local biodiversity as well as removing a proportion of the nutrients which can lead to eutrophication," it continued.
Meanwhile, as advocates of seaweed biomass promote marine algae for use in anaerobic digesters, the Carbon Trust launched last week a challenge to develop algae oil as a biofuel alternative to fossil fuels (see this New Energy Focus story).
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