OWA launches high voltage array systems joint industry initiative
A new project to build
industry consensus on setting the future standard array voltage for offshore
wind farms has been launched. The High Voltage Array Systems (Hi-VAS) project
is the latest joint industry initiative led by the Carbon Trust as part
of the Offshore Wind Accelerator (OWA) programme. It aims to understand
the costs, benefits and technology challenges associated with raising the
The wider consortium of the Hi-VAS project consists of seven wind farm
developers: EnBW, Equinor, Ørsted, RWE, ScottishPower Renewables, Shell
and Vattenfall. The half-million pound project is set to run until January
2022 and is being delivered by the Carbon Trust, TNEI and Petrofac. It
follows previous OWA work in raising the array voltage from 33kV to 66kV,
where similar industry consensus was reached five years ago.
As offshore wind turbines are set to grow beyond 15MW, it is expected that
the current standard array voltage of 66kV will be insufficient. A higher
array voltage will be necessary to enable cost-effective string lengths
and layout designs; reduce electrical losses; and ultimately enable the
deployment of larger turbines.
However, uncertainty remains as to what the optimum next array voltage
is; the appropriate timing for making the change to the next array voltage;
and the most efficient path to the next array voltage in terms of technology
and regulatory development.
Whilst, in time, the array system supply chain could gradually accommodate
the next generation of turbines and regulators would progressively move
to accommodate changes in array system technology, a collaborative approach
will accelerate this transition to ensure the industry can continue to
reduce costs and increase capacity.
According to the project consortium, supply chain and regulatory stakeholders
will be engaged throughout the project to provide insights into the practical
challenges faced in raising the voltage; to provide constructive criticism
and to ensure the project’s findings are supported and acted on by the
The technical and regulatory changes required when raising the array voltage
will be examined. Detailed cost-benefit analysis, risk analysis and preliminary
design studies will be performed for a range of possible future array voltages
and a range of future turbine sizes (14-20MW) to identify the next optimum
A series of engineering design studies will examine how each component,
standard, method, or regulation associated with the array system may need
to adapt. Recommendations on how to address barriers identified through
the project will be included in an industry roadmap to ensure the recommendations
are taken up by the supply chain and regulators.
Jan Matthiesen, Director Offshore Wind at the Carbon Trust, commented:
“Offshore wind is a leading solution to tackle climate change globally
and we must continue to innovate to accelerate and optimise deployment.
The OWA High Voltage Array Systems project is the latest collaborative
industry project to join the significant portfolio of offshore wind research
and development programmes run by the Carbon Trust. By demonstrating a
strong alignment among developers a clear and consistent message can be
sent to the supply chain, which will ultimately accelerate the introduction
of high voltage array systems and hence the next generation of wind turbines.”