Solving the conundrum as to how you get 40GW of offshore wind into an unsuitable grid system by the end of this decade is an increasingly urgent question testing politicians and regulators.

At the heart of the problem lies an offshore grid which has mushroomed into multiple individual point-to-point links to shore developed in an era when offshore wind was a nascent sector with expectations of as little as 10GW being built by 2030.

Coupled to this inadequate offshore set-up is an under-resourced onshore transmission system, ill-equipped to handle the large volumes of clean energy expected to make landfall over the coming decades.

Major offshore wind players and energy network firms are voicing growing disquiet over outdated industry regulation holding back investment in what is rapidly turning into the biggest issue facing the UK sector.

“In the context of UK offshore wind, all is not rosy,” says RWE Renewables chief commercial officer and UK country chair Tom Glover. “The current framework for offshore grids is not fit for purpose.”

Keith Anderson, chief executive of Iberdrola subsidiary ScottishPower, says if the country wants to accelerate the path to its legally binding target of net-zero emissions by 2050 — which will require a major shift to electric vehicles and electric heating — it will need to “reconstruct, redesign and redeliver the transmission system. It has to be at the forefront of everything you want to do in the UK”.

In the context of UK offshore wind, all is not rosy

RWE Renewables chief commercial officer Tom Glover

Glover told the recent Energy UK annual conference: “The current point-to-point approach is resulting in planning issues relating to multiple landfall points, and we risk undermining the goodwill and incredible progress made if local people see too many, seemingly uncoordinated cable routes.

“We need a more strategic and coordinated approach with a new offshore regulatory regime in place by 2023 at the latest if we are to meet the 2030 target. But this isn’t enough as critically any new offshore regime needs to be coordinated with the required onshore investments.”

Glover said the new regulatory regime should allow for “anticipatory investments” in the onshore grid networks “that will be needed for the offshore wind farms we know are going be built, and roughly where they are going to come ashore”.

Offshore wind developers have faced increasing discontent in coastal communities in the East Anglia region, with a legal challenge mounted against Vaffenfall’s 1.8GW Norfolk Vanguard project, and local politicians calling for a freeze on all planning consents until offshore projects are able to share connections.

“As the southern North Sea becomes the world’s largest centre for offshore wind infrastructure, East Anglia is in danger of being ruined by the dozens of Wembley [Stadium]-sized substations and thousands of miles of underground cabling required to connect these new wind farms to our national grid,” said George Freeman, Conservative MP for mid-Norfolk.

Freeman has successfully forced the grids issue onto the UK’s political agenda, convincing ministers to launch a far-reaching inquiry into the offshore transmission system chaired by energy minister Kwasi Kwarteng.

The argument for some form of offshore network system has been won

UK energy minister Kwasi Kwarteng

“The argument for some form of offshore network system has been won,” Kwarteng told a recent parliamentary debate, where he confirmed government support for an integrated offshore "ring main".

The review is looking into the working of the current Offshore Transmission Owner (OFTO) regime and will address any barriers it creates for future offshore wind deployment. It has been split into two parts firstly a medium-term workstream to consider wind projects due to be connected to the grid between 2025 and 2030, and a long-term workstream to look at longer term, post-2030 projects.

The latter workstream will also consider the role multi-purpose hybrid interconnectors between the UK and neighbouring markets can play in delivering 2050 goals.

The medium-term workstream could go some way towards appeasing the concerns of some developers that several large wind projects which have already progressed through the planning process should not be subject to retroactive changes to the offshore grid regime.

“Because this government review is ongoing it has injected some uncertainty into the whole system for offshore wind developers,” Fintan Slye, director of National Grid ESO tells Recharge. “I think it’s right to split the review into two workstreams as projects which are already in mid-development are a critical part of the huge wind farm pipeline we need to deliver each year if we are to meet 40GW by 2030, and 75GW/80GW by 2050.”

Kwarteng says the government will publish an update on the progress of the review by the end of this year, and will present a new approach for dealing with the offshore transmission system in 2021.

“The 40GW of offshore wind desired by the government by 2030 puts greater urgency on the review,” Mike Blanch, associate director at renewables consultancy BVG Associates, tells Recharge.

The 40GW of offshore wind desired by the government by 2030 puts greater urgency on the review

BVG Associates associate director Mike Blanch

“It also puts more focus on building a grid suitable for 40GW promptly. This can only mean high-voltage direct-current [HVDC] with its higher capacity and lower cable route footprint comes more to the fore in consideration.”

As part of the government review, the country’s electricity system operator National Grid ESO has launched a detailed UK-wide study showing how around £6bn ($7.7bn) of savings could be made by 2050 through using shared transmission infrastructure to link offshore wind farms to the onshore grid, rather than point-to-point connections.

This integrated approach comprises offshore converter platforms that allow multiple wind farms to connect into them, which then transmits all their power ashore using HVDC export cables. The reduction in physical infrastructure that this would bring would amount to as much as 50% over the next 30 years.

While the majority of the technology required to move to this integrated approach already exists, or will become available by 2030, Slye says there is still a clear need for the UK to invest in accelerating the deployment of HVDC circuit breakers, a switching device designed to protect electrical circuits from the damage caused by excess current from an overload or short circuit.

“HVDC allows you to have a more integrated offshore substation, so it would be possible to connect in more wind farms and to operate them more flexibly. Even without circuit breakers you could still get a long way by deploying HVDC technology, but if you want to get a full suite of benefits they would certainly give you added flexibility.”

RWE Renewables senior regulatory affairs manager Nicola Percival warns that while National Grid ESO’s fully integrated grid model “looks like a really good end goal, it’s not something we can do overnight because of the long lead time of projects and the regulatory structure we have today”.

She emphasises that a key factor for wind developers is that a new regime needs to be in place by 2023 as projects expected on line in 2030 will start to seek planning approval. “At that point people are spending money so to change things around not only costs time but also money.”

“We may have a government target for 40GW and for 2050 net-zero, but the current regulatory frameworks aren’t designed to deliver at that pace,” Percival adds.

Slye explains that changes would be needed to both the regulatory and legislative regimes if offshore wind projects are to coordinate on exporting power.

UK electricity regulator Ofgem and the Department for Business, Energy and Industrial Strategy are working together to study studying early opportunities for co-ordination between offshore wind farms, asking developers to self-identify and explain how they might be able to co-ordinate with other offshore projects and what the barriers might be to doing so.

Ofgem’s director for networks, Akshay Kaul, tells Recharge that his organisation is working with the government and industry to develop proposals for “a co-ordinated programme of anticipatory investments” that would enable 40GW of offshore wind farms off the UK.

The regulator — which is tasked with providing best value at the lowest cost to energy consumers — is also aiming to secure billions of pounds of new investments in the grid to enable the UK to meet its net-zero ambitions.

“The grid must be able to cope in an era of rapidly increasing volumes of renewable power, intermittent generation, flexible electricity markets, undersea interconnectors, battery storage, and households both taking electricity from and supplying it back to the grid,” says Vattenfall UK country manager Danielle Lane.

“But this is about more than supplying power to people’s homes – the grid is also the lifeline which will enable industries right across the economy to move away from fossil fuels and rely on clean electricity instead.”

Wind

'All is not rosy': Why UK's 40GW offshore goal needs grid connections regime overhaul