The main aims are to assess the costs, benefits, and technology issues associated with raising the array voltage.
The Hi-VAS consortium comprises seven wind farm developers: EnBW, Equinor, Ørsted, RWE, ScottishPower Renewables, Shell, and Vattenfall. Petrofac, TNEI, and the Carbon Trust are working on the current project, which builds on previous OWA work that led to raising of the array voltage from 33 kV to 66 kV.
As offshore wind turbines’ capacity increase beyond 15 MW, the current standard array voltage of 66kV will not be adequate.
A higher array voltage will be needed to achieve cost-effective string lengths and layout designs; reduced electrical losses; and the deployment of larger turbines.
However, there is uncertainty over what the optimum next array voltage should be, the timing for making the change, and the way forward in terms of technology and regulatory development.
Although the array system supply chain could over time accommodate the next generation of turbines and regulators would progressively work to manage changes in array system technology, a collaborative approach could accelerate the transition.
The study team will seek feedback from the supply chain into the practical challenges likely to arise in raising the voltage, and will also examine the required technical and regulatory changes, performing cost-benefit analysis, risk analysis, and preliminary design studies for a range of potential future array voltages and turbine sizes (14-20 MW).