Oceanographers at Bangor University in Wales are calling for research into the environmental impact of turbulence caused by tidal flow past floating deep-water wind farms.
New research is needed to fully understand how locating varying types of wind turbines could affect not only the seabed, but the waters, and everything they contain, according to Dr Ben Lincoln of Bangor University.
Britain leads offshore wind energy production globally, with current power generation meeting one-third of the national demand (~10GW), and floating wind in deep shelf sea areas has been identified as a major route in the “net zero” goal.
A current target to produce 50GW by 2030 is an increase of 67% on the target set just 12 months ago.
However, Dr Lincoln and fellow researchers notes that offshore sites at a depth of over 50 metres are very different in nature to shallow coastal sites used so far.
They say that with an additional 20,000 wind turbines set to be built in British water, there is a need to ensure full awareness of the positive and negative effects their presence could have on the surrounding environment.
“Our shelf seas are fully mixed during winter, but during summer months the deeper regions stratify, with a warm surface layer overlying the cooler water below,”Dr Lincoln has said in a statement.
“ This triggers a phytoplankton bloom which can be seen from space and forms the base of the marine food chain, supporting fish, seabirds and whales,”he explains.
“ During summer months following the spring bloom, phytoplankton growth is supported by nutrients stirred up from below by turbulence associated with wind and tides. This turbulence also mixes oxygen down to the deep water, where it is required for other key biological processes,”he notes.
“Environmental assessments for the shallow shelf seas have focused on wildlife using or living within the affected areas. The difference with the deeper seas is that the fundamental functioning of the seas themselves could be affected,” Lincoln says.
“Turbulent mixing determines the timing and rate of the food supply on which marine ecosystem and key species rely. Flow past deep water wind farms will introduce ‘anthropogenic’ or man-made turbulence, and increase mixing,”he says.
“ This fundamental change could lead to significant regional impacts, which must be assessed. However, impacts are not necessarily negative, with the potential to enhance productivity and offset the impact of increasing stratification due to climate change,”he says.
“There’s no doubt that this growth in renewable energy is essential to meet global 2050 net zero commitments,” he says.
More details are in a research paper: Anthropogenic Mixing in Seasonally Stratified Shelf Seas by Offshore Wind Farm Infrastructure, published in Frontiers.