Seaweed cultivation pilot at wind farms
On 29 February, a colossus of 20 by 20 metres departed from the isle of Texel to engage in a pilot for seaweed cultivation. Its destination was a former sand extraction area, ten kilometres west of the island. By the end of June, the Dutch Consultancy Ecofys aims to deliver the first tonnes of Dutch seaweed for the production of fish and animal feed, biofuels and energy. ECN is collaborating with Ecofys to study the options of bio-refining seaweed into proteins, components for biofuels and fuel for energy generation.
The ship with the pilot module, several hours before departure at night (photo Ecofys)
Food and energy
Seaweed yields both nutrients and energy. The Irish company OceanFuel is already extracting proteins from seaweed that are suitable as replacement of fish and animal feed. Large-scale production at sea will enable the replacement of large areas in use for soya production. This combination of sustainable food and energy production fits well in the idea of the ‘bio-based economy’. This is offshore renewables in the broadest sense of the word.
The innovative seaweed cultivation module consists of a number of steel cables that are kept two metres below the water surface by anchors and floating buoys. Horizontal nets of 10 by 10 metres are placed between these cables. Small seaweed plants that commonly occur in the North Sea are fastened onto these nets. The aim of the pilot is to demonstrate the extent to which the module is ‘North Sea proof’, to find out how the plants will develop and what the ecological effects will be. If the pilot is successful, the project partners will have realised a global milestone: offshore cultivation of biomass (bio-offshore).
Nature park at sea
The pilot also aims to demonstrate that the module is suitable for seaweed cultivation at offshore wind farms. Potentially, seaweed and wind turbines combine well. Wind farms are closed to shipping and fishing. This creates a kind of nature park at sea. Fish will be drawn to the fields of seaweed and use them for shelter and even as breeding ground. This will certainly be the case if the fields grow by several hectares, which is theoretically possible.
The module has been developed by a consortium led by Ecofys, consisting of Eneco, ECN, BLIX, Van Beelen Netting, Pipelife, OceanHarvest, VIRO and De Vries & Van de Wiel. The NIOZ Royal Netherlands Institute for Sea Research facilitated the construction of the module in its knowledge harbour, supported by businesses from North Holland. The Dutch Ministry of Economic Affairs, Agriculture and Innovation financed the module through the so-called Small Business Innovation and Research (SBIR) scheme established by NLAgency.