Norwich to Tilbury (East Anglia GREEN) - Electricity System Operator (ESO)

CLA East Surveyor Tim Woodward provides an update on a new report from the ESO

The Electricity System Operator (ESO) operates Britain’s electricity system, and has a role in developing the future grid system. Although it is currently part of the National Grid PLC Group, it is a legally separate business, and from later this year, will become an independent public corporation, advising the Government on the whole energy system in the UK.

Many offshore windfarms in the North Sea are either already generating electricity or will be connecting to the grid in the region in the next few years. In addition, interconnectors will bring power from Europe. This means that the grid system in East Anglia will need significant upgrading in order to cope with increased loads, and the ESO has recently carried out an assessment of different network options for the electricity grid in East Anglia. National Grid has proposed the construction of an onshore 400kV cable route, running for 180km (approximately 111 miles) from south of Norwich to Tilbury, carried on 50 metre-high pylons, other than in the Dedham Vale, where the route would run underground. This has been very controversial, and has met with considerable opposition from community groups, local authorities, and MPs in all the affected constituencies.

While the CLA does not oppose nationally significant infrastructure projects, and recognises that the existing grid may indeed be inadequate to cope with extra generation, we believe that hitherto, alternatives to intrusive overhead pylons have not been adequately considered by National Grid, and that further active consideration should be given to the installation of an offshore ring main around the East Anglian coast, so that generation from offshore wind farms and continental supplies could be connected to it, reducing the need for further onshore electricity infrastructure.

The ESO’s East Anglia Network Study assesses a number of different options, six developed in collaboration with National Grid Electricity Transmission, and four proposed by community representatives.

The study assesses the options using a variety of criteria, including deliverability, environmental impact, community impact, and economic impact, but does not come out in favour of any one option. The report says. “What is evident is there is no single option that minimises impacts across all the metrics…” In essence the conclusion seems to be that the onshore option (the pylon line that is being vigorously opposed in the region) can be delivered earliest, but if a later delivery date is acceptable, then an undergrounded or hybrid onshore/offshore options are “comparable in ranking”. The study does not consider a fully coordinated offshore option, which those opposing the onshore pylon line believe would reduce the amount of infrastructure needed, although the Government encouraged voluntary coordination of offshore infrastructure through the Offshore Coordinated Support Scheme (OCSS), although only two wind farm operators are currently involved.

ESO now expects National Grid Energy Transmission (NGET) to consider the findings of the study as part of the development of the Norwich to Tilbury upgrade, and for the Government and the OCSS operators to use the results of the study to help with the progression of the OCSS. The CLA has not yet seen any reaction from the Offset group of MPs (whose constituencies are affected by the project), but opponents of the scheme have expressed disappointment at what they believe are significant omissions from the conclusions made.

Read the full report here >