As offshore wind continues to grow, more coordination is needed

In this latest RenewableUK blog, Daniel De Wijze, Policy Analyst, details the extra co-ordination required across the offshore wind industry if the UK is to meet ambitious net zero targets and continue to increase offshore wind capacity over the coming decades.

Daniel De Wijze leads on RenewableUK’s work on network charging and regulatory issues

The UK leads the world in offshore wind, with more installed capacity than any other country, with over 10GW of installed capacity. The rollout of offshore wind over the past decade has been a great success, but in order to meet our net zero targets, we need to go further and faster. In order to achieve the Government's 40GW target by 2030, and over 100GW by 2050 as required by the 6th Carbon Budget, changes are needed in the way that offshore wind and associated grid infrastructure are designed, consented, and built.


Currently, individual windfarm projects each have their own connections back to shore, where they link up with main interconnected transmission system (MITS). These offshore links are built by the windfarm developer and then sold to an offshore transmission owner (OFTO), as required by UK law. The problem is that adding new cables and substations for every new windfarm has big environmental and local impacts, particularly for coastal communities; these impacts will only increase as the number of windfarms does. However, if windfarm projects could coordinate and share infrastructure in a more efficient manner, the number of offshore links would be reduced, mitigating these impacts.



This is where the offshore transmission network review (OTNR) comes in. The OTNR looks at the way that the offshore transmission network will be designed and delivered. It aims to bring together key stakeholders involved in the timing, siting, design and delivery of offshore wind to consider all aspects of the existing regime. One challenge for the OTNR is the number of different key stakeholders, which includes Ofgem, BEIS, The Crown Estate/CE Scotland, National Grid ESO, Defra and local government in Scotland and Wales.

RenewableUK has responded to two OTNR consultations, which ask about the different workstreams in the review.


The recent BEIS consultation focuses on the Enduring Regime, which considers offshore transmission in the years after 2030. In the long-term, RenewableUK and its members are in favour of fully integrating the onshore and offshore grid, with as far as possible the same technical and commercial arrangements. We believe the Enduring Regime should consider a wider energy systems-based approach, which includes planning around decarbonisation of heat and transport and the role of hydrogen, storage, and flexibility assets. Policy may need to change in order to support a more efficient level of anticipatory investment in the regulatory frameworks of transmission networks.


Central to this workstream are the strategic plan and holistic network design (HND). We argue in favour of a strategic plan which is broad in scope – it should be a top-down model of development, that sets out where windfarms should be built in order to deliver on our aforementioned targets. In other words, if we need a certain number of GW of offshore wind by a certain date, the strategic plan will set out where that wind should be built, considering environmental impacts, the needs of local communities, and cooperation with other seabed users (for example mining, fishing, and defence). A good strategic plan can provide much needed stability and certainty for investors and developers.


It is not possible to strategically plan out the grid network without understanding the location of future windfarms, so these elements need to be considered holistically. The energy system operator (National Grid ESO) should use the strategic plan to undertake holistic network design (HND) – this figures out where the grid should be built or reinforced in order to connect up all the new windfarms we need. The best model for delivery should be identified by the ESO, with a focus on delivering net zero at lowest cost to the consumer.


A more coordinated approach to detailed design and delivery will help to speed up the process of adding windfarms to the grid, but more information is needed on how this will work. For instance, the UK could adopt a model where a single process is used to grant financial support, seabed rights and a connection agreement, as seen in countries such as Germany and the Netherlands. However, this would be a big change to how windfarms are delivered, and would impact on the competitive nature of the UK market that has worked well to drive innovation and lower costs thus far.


Additionally, care must be taken to ensure developers are supported and are not taking on an unfair amount of risk. At present, developers have control over surveying, design and construction, and therefore take on the risks for delivering a project. If some of this control is removed to create a more centralised model, the allocation of risk changes too, and other stakeholders that are now involved (such as TOs or OFTOs) must have sufficient motivation to deliver projects on time.


BEIS and Ofgem will now consider the responses to their consultations. In the meantime, the different OTNR workstreams continue to move forward. RenewableUK will work closely with the industry to ensure that any regulatory and legislative changes support the buildout of offshore wind and move us closer to a more coordinated grid that can deliver on our net zero targets.

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