For the United Kingdom to build up to its target 75 GW of offshore wind generation by 2050, new thinking is required on the transmission infrastructure around it, says David Blackman in a recent article in trade journal, Utility Week, that looks at the options set to be considered in a government review and how experts see an offshore grid developing.
RCG’s Chief Technical Officer, Elaine Greig, was interviewed by Utility Week for the article. Elaine is a member of the Institution of Engineering and Technology’s Energy Policy Panel.
Under current transmission arrangements, offshore windfarms in Britain are directly connected to the National Grid via point-to-point connections. In East Anglia, the local disruption from multiple the landfalls to connection points in the same region is becoming an issue. Elaine pointed out that with the UK offshore wind industry on target to generate 75 GW by 2050, these issues could be more widespread.
Other European countries have set up offshore shared transmission networks, Elaine said, partially reflecting their differing geographies. Germany’s offshore windfarms, for example, were geographically concentrated in parts of the North Sea. The distance between shore and the wind farms meant that it made sense therefore to create shared connections to the mainland.
The problem will become more pressing as more new windfarms are earmarked by the Crown Estate in its upcoming seabed leasing allocation, says Elaine: “With Round Four there will be more hotspots, so this is about making sure those hotspots don’t become barriers to offshore wind.”
Onshore meanwhile, delivery of a single and larger corridor is potentially easier because it would involve having to negotiate with fewer landowners in order to secure access to the cables for maintenance and operation.
The article concludes that a major obstacle to the development of a more integrated offshore transmission grid has been the regulator, Ofgem, which has taken a cautious approach to network extensions, and that the current regulatory arrangements do not promote co-ordination.
The UK government has announced the scope of a review into the existing offshore transmission regime to address the barriers it presents to further significant deployment of offshore wind, with a view to achieving net zero ambitions.
The review will be led by the Department for Business, Energy & Industrial Strategy (BEIS) with support from a range of government and Industry bodies and an industry expert group.
The review will be split into two workstreams. The “medium-term” workstream will seek to:
identify and implement changes to the existing regime to facilitate coordination in the short-medium term;
assess the feasibility and costs/benefits of centrally delivered, enabling infrastructure to facilitate the connection of increased levels of offshore wind by 2030;
explore early opportunities for coordination through pathfinder projects, considering regulatory flexibility to allow developers to test innovative approaches; and
focus primarily on projects expected to connect to the onshore network after 2025.
The “long-term” workstream will seek to:
conduct a holistic review of the current offshore transmission regime and design and implement a new enduring regime that enables and incentivises coordination while seeking to minimise environmental, social, and economic costs;
consider the role of multi-purpose hybrid interconnectors in meeting net zero through combining offshore wind connections with links to neighbouring markets and how the enduring offshore transmission regime can support the delivery of such projects; and
focus on projects expected to connect to the onshore network after 2030.
The Government says it will publish an update by the end of the year, with a view to providing clarity for an enduring approach in 2021. Policy recommendations and proposed changes to the existing regime will be delivered through its normal consultation processes.