Understanding the impact of renewables on the marine environment
As Europe moves ever closer to its renewable energy targets, increasing attention is being placed on wave and tidal energy as a source of renewable energy. Indeed, wave energy is an abundant renewable resource, and is starting to be exploited by several European countries. What is especially attractive about sea waves is their high energy density, which is estimated to be amongst the highest renewable energy sources. While we may know about the benefits, little is known in general of the impact that they have on the marine environment.
A scientific team has gathered leading experts from across the British Isles to begin work investigating the impact that these renewable energy sources have on the marine environment. Their vital research work will be conducted at three marine renewable energy test sites, the European Marine Energy Centre (EMEC), WaveHub (a grid-connected offshore facility in south-west England) and Strangford Lough. Their research falls under the auspices of the Flow and Benthic Ecology 4D (FLOWBEC) project which will run for 3 years and costs GBP 1.2 million.
FLOWBEC is led by the National Oceanography Centre (NOC), and is funded by the Natural Environment Research Council and Defra (the Department for Environment, Food and Rural Affairs). The institutions involved include the Universities of Aberdeen, Bath, Edinburgh, Exeter, Plymouth, Queens University Belfast, Plymouth Marine Laboratory, Marine Scotland Science, the British Oceanographic Data Centre, EMEC, and one of the world's leading tidal turbine developers, OpenHydro Ltd.
Dr. Paul Bell, a marine physicist at the NOC who is leading the project, highlighted the diverse background of those taking part in the project. "This is a truly multidisciplinary study bringing together researchers from all over the UK to shed light on how extracting wave and tidal energy from our oceans might affect the environment," he said. "If there are effects they could be beneficial to wildlife - but if any are negative, our research may suggest ways of avoiding them in future designs."
At all these sites, a range of measurement and modelling systems will be used to improve our understanding of the interaction of hydrodynamics with the wildlife found around them. In particular, the research will focus on how the various species choose to use areas of the water column with different physical characteristics, and how the surrounding environment is affected by the presence of the renewable energy structures and identifying their interaction with tidal technology.
Dr. Philippe Blondel, Senior Lecturer in Physics and Deputy Director of the Centre for Space, Atmosphere and Oceanic Science at the University of Bath, commented that: "Using waves and tides as a renewable energy source is more predictable than solar or wind energy, and of course there isn't the same visual impact. Tidal energy devices alter the local water flow and this project aims to measure and assess whether this has an effect on the wildlife around it."
"We'll be sharing the knowledge gained with other users and providing data as an open resource for environmental scientists at the end of the project. Our presentation of the first results at the European Conference in Underwater Acoustics, a few days after recovery, has been extremely well received by operators and researchers working with marine renewable energies."
The researchers have combined two state-of-the-art sonar systems on a seabed frame placed within 25 metres of an OpenHydro structure. The structure is a marine turbine much like a small enclosed fan or jet engine fan which is silent and invisible from the surface, and located at such a depth that it presents no navigational hazard. The sonar systems will monitor fish and diving seabirds that pass through or feed around the location. Most importantly they will be able to finally assess how fish and seabirds interact with the installation.
Traditionally these sonars have been mounted on a ship as separate units looking down at the seabed. In this project they have been specially adapted to operate autonomously in combination for several weeks from the seabed facing upwards. Collecting the data in this way allows imaging of a full, so-called, acoustic curtain all along the tidal flow and around the turbine in a highly challenging environment.
Dr. Beth Scott, Senior Lecturer in Marine Ecology at the University of Aberdeen, spoke about the technology and the partnership involved: "It is an amazing feat of collaboration, involving such a wide range of expertise, that has allowed us to produce and successfully deploy the combined type of instruments that will finally start to provide the ecological information so badly needed by the marine renewables industry."
"After detailed analysis these data will determine how mobile animals, such as seabirds and their fish prey, behave around marine renewable devices over an entire fortnightly tidal cycle - as the instruments successfully 'pinged' away and collected data for every second of that two-week period. This research will help to determine the actual risk of collision between marine animals and turbines and will allow governmental marine spatial planners a step change in the level of certainty about where to allow renewable developments."
Provided by CORDIS