Oil emissions from offshore windfarms – impacts on marine

The objective is to determine potential environmental impacts of diffuse and accidental oil spills from offshore wind turbines on marine biodiversity. The longer-term goals are to eliminate (1) adverse ecotoxicological effects and (2) the discharge of persistent chemicals. This research will improve the basis for the environmental risk assessment and management of an expanding offshore energy industry of vital importance for the green transition. The offshore transition from oil platforms to windfarms will inevitably lead to enormous reductions of CO2 emissions and chemical discharges to the marine environment. However, it has hitherto received little to no attention that the operation of wind turbines is associated with considerable amounts of uncontrolled discharge of various oils and fluids to the sea. These are hydraulic fluids for control of wing pitch, vital lubricants for various mechanical parts such as gear oil, and even diesel for auxiliary electricity generation. A single large wind turbine carries up to 8000 L of such fluids (Ole Lund Jensen, Vestas Wind Systems, private communication). The fluids contain beside base oil components many specialized chemical additives preventing system deterioration. Such additives include biocides, corrosion inhibitors and antioxidants at total concentrations of 1-3%. The additives are important for minimizing service frequency, maximizing run time and thus both energy yield and operational costs. Oil leakage to soil is known for land turbines. Offshore windmills are larger and operate under harsher conditions making leakage more likely and maybe also more frequent. Despite this, chemical emissions from marine windfarms and related effects on marine biodiversity remain to be studied. With this project, we aim to quantify the potential harmful effects of oil emissions and point at solutions to avoid that an increasing windfarm industry accidentally may cause unintended adverse impacts on marine biodiversity. The project focuses on three factors that govern the discharge and effects of oils from off-shore wind turbines on marine biodiversity: 1) the influence of additives on the stability of oil droplets after discharge to the Sea, 2) the ecotoxicity of fresh and used oils to Oil emissions from offshore windfarms to marine species, and 3) the environmental persistence of oil constituents. Special attention will be paid to the role of oil droplets, since these can co-transport oil constituents and have significant, and unexpected, negative impact on fish. Besides providing novel scientific insights, the project will generate the first knowledge needed to develop chemical regulatory practices for offshore windfarms. The tailored workflows and analytical methods for testing, developed in this project, can inform practices for additive substitution and predictive tools for environmental impact evaluation. We have assembled an inter-disciplinary project team of excellent scientists with long-standing expertise in the above three main areas including the adjacent areas of analytical chemistry, and the translation of scientific findings to environmental impact assessments.