Can offshore renewables and aquaculture together provide sustainable energy, food and jobs?
THE Scottish aquaculture industry is eager to expand into new locations, which at the moment tend to be available only in deeper waters, further from the coast. The harsher wave conditions, and the need to protect the environment, are among the challenges that need to be tackled.
But, nowadays, aquaculture is only one of the many ‘blue economy’ industries aiming at a sustainable use of the ocean space: offshore renewable energy, maritime transport, biotechnology, tourism, and others – can these industries work together, helping each other and diminishing the impact on the environment?
An international team of 24 researchers, funded by the UK (EPSRC, NERC) and China’s (NSFC) research councils, think so.
Dr Maurizio Collu, the project leader, from the University of Strathclyde, said: ‘Offshore multi-purpose platforms - that is, platforms that serve the needs of multiple industries - could reached by a single industry acting alone.
‘For example, offshore wind turbines, complemented by a suitable energy storage system (batteries), could reliably and sustainably power aquaculture systems.
‘Furthermore, optimising the layout of a wave energy converter array around aquaculture cages, it is possible to create a ‘sheltered area’ in their wake, opening new areas of the sea that were not accessible before.’
Dr Collu, who presented his research at the MASTS conference in Glasgow in November, said he and the team were now working on the techno-economic feasibility of installing wind to provide all the necessary power to operate and maintain a typical west of Scotland salmon farm.
At the moment, where a connection to the shore is not feasible, diesel generators are used to provide this power, therefore using non-sustainable fossil fuels and emitting greenhouse gases into the atmosphere.
often done onshore), the power requirements are well within the capabilities of off-the-shelf small wind turbines (with a rated power around few hundreds kW) which, if coupled with a suitably sized energy storage system, can cover the power needs all year round.
Feeding barges can be used as support struc sharing the costs, said Dr Collu.
The questions that the international, multi-disciplinary team are answering through research are: will the feed barge still be stable if one or more wind turbines are installed on it? Will it be safe to work on such platforms?
What would be the environmental impact of such a combined system? Will the noise of the wind turbine have an impact on salmon growth? Will the local communities accept the presence of these wind turbines?
A stakeholder workshop, involving a number of governmental insti the end of August, hosted by the Scottish Association for Marine Science (SAMS), a member of the consortium: feedback from a wide range of expertise and point of views were collected and are now being taken into account.
Those present included representatives from Crown Estate Scotland, SAMS, Albatern, the Scottish Aquaculture Innovation Centre, University of Dundee (MUSES project), AquaMoor, and Allan Thomson, former founding director of Wavegen and Aquamarine Power.
Dr Collu said the idea of having renewable energy systems to sustainably power aquaculture systems was well received by the sector, and at the moment no major obstacle was foreseen. Suggestions on a careful evaluation of the site and the relative environmental conditions were made.
The concept is not only about untapping ocean resources, it is also about providing sustainable energy, food, jobs, and economic prosperity to isolated/remote communities, said Dr Collu.
In Scotland, there are island communities which do not have round-the and Shetland, which is now enjoying a 24-hour electricity supply thanks to a local renewable energy scheme.
In China, there are hundreds of remote island communities that have seen their populations in rapid decrease or being relocated, due to the lack of access to basic services, such as energy and freshwater. A multi-purpose platform coupling aquaculture systems, offshore renewable energy devices, and desalinisation units, could provide the basic services needed by any small community, and enable their economic development.
ing structure, extracting energy from the wind and waves, and providing this energy not only to the closely co-located aquaculture systems, but also to the local community grid.
These remote islands, of rare natural beauty, are also seen as having a huge potential for the tourism industry.
A scale model of the innovative concept will be experimentally tested in the ocean basins of Harbin Engineering University and of the National These will be useful not only to prove, experimentally, the validity of the concept in operational and survival conditions, but also to validate the numerical tools developed by the UK and Chinese engineers, to analyse and design the full scale concept.
In conclusion, oceans are seen as the next ‘agricultural revolution’ frontier, where huge and untapped opportunities are available, some of which could have an impact in the next few years. But we must be careful to proceed sustainably and in an environmentally compatible way., said Dr Collu.
Multi-purpose platforms, maximising the synergies among different offshore industries, could make a promising contribution to this revolution.
This INNO-MPP project is supported by the UK Engineering and Physical Sciences Research Council UK (EPSRC) and the Natural Environment Research Council UK (NERC) and the Natural Science Foundation of China (NSFC).
Above: Dr Maurizio Collu Opposite: the concept might look Right: Fair Isle