Parts of controversial Suffolk grid upgrade could be moved offshore

The economic impact of transferring elements of a controversial grid upgrade from the East Anglian countryside to the North Sea could “soon be cost-neutral”, a Suffolk MP has claimed.

Central Suffolk and Ipswich North MP Dan Poulter backed proposals to move parts of the scheme offshore, during energy security and net zero ministers’ question time.

He referenced the Electricity System Operator’s (ESO) recently published review of the East Anglian network as evidence for why the scheme should be moved offshore.

The ESO review examines 10 options for upgrades that would enable the region’s transmission network to cope with new wind farms being developed offshore.

National Grid is currently proposing the construction of a new, mainly overhead, transmission line between Norwich and Tilbury, to supply power to London and the south east, which would cut through the Norfolk and Suffolk countryside.

The line consists of 158 km of new overhead line supported by 520 pylons, along with four sections of underground cabling, some of which would run through Suffolk’s designated Dedham Vale National Landscape.

The review also takes into account proposals, unveiled last year by National Grid and wind farm operators, for the proposed 2GW offshore Sea Link between Suffolk and Kent, which is designed to ease network constraints within East Anglia.

The ESO’s review looks at a series of different options, consisting of different mixes of onshore overhead and underground lines as well as offshore grid.  These include four options proposed by community representatives

The report’s economic analysis, which takes into account both capital costs and overall system impacts of the different options, ranks the onshore option highest because it is deliverable earlier in 2030.

If a later delivery of 2034 is assumed the undergrounded HVDC proposal as well as hybrid onshore and offshore options are comparable in ranking, it says.

Pointing to the review, Poulter said: “The electricity system operator review indicated that it will soon be cost-neutral to have an offshore option for that same energy transition, and that multiple points for connecting offshore wind turbines to the grid are facing planning problems.”

He called on energy secretary Claire Coutinho to engage with National Grid to “get it to do the right thing and look at a cost-neutral option of offshore transmission, rather than the current onshore proposal”.

The review also finds that among the most expensive of the options in terms of economic impact is one backed by ex-environment secretary of state Therese Coffey, who is MP for Suffolk Coastal, to use predominantly offshore transmission lines coming ashore at Bradwell in Essex, where there is a grid connection for the redundant nuclear power station site.

The report highlights Bradwell as “particularly environmentally challenging” because it has more overlapping sites of international designation than the other proposed landing points.