An investment of over £183 million is being recommended by National Grid ESO to support network reinforcement in 2021.
This comes as part of its annual network options assessment (NOA), a report recommending which reinforcement projects should receive investment during the year.
Looking ahead, the NOA found a need to invest over £16 billion to manage heavily constrained system boundaries through asset build options into the mid-2030s. The key driver in this is the large increase in renewable generation, according to National Grid ESO, particularly in the north and east of Great Britain.
When looking at the possible network reinforcements that may be required over the next year, 171 options were assessed. These were split into a number of categories: developing new circuits (48), upgrading existing circuits (50), building new substations or reconfiguring existing substations (7), controlling power flow (27), alternative options (4), voltage and stability constraints (27) and ESO-led commercial solutions (8).
Of these 171 options, 45 were recommended to proceed. Of those 45, four are ESO-led commercial solutions, which are targeting the north of England and Scottish border region and the south east coast region, and are set to provide up to £2.1 billion in consumer savings.
Options set to proceed include upgrading the substation in the south Humber area, installing an alternative power control device along Creyke Beck to Thornton and new 400kV double circuits across the country including two in East Anglia among many others.
The report also identified the need for four Anglo-Scottish subsea reinforcements along the east coast as well as several large onshore reinforcements that combine to facilitate north-to-south power transfer.
Alongside this, a key focus of the NOA was interconnection, with the ESO continuing to forecast a growing volume of interconnection capacity over the next ten years in the south and east of England.
This builds upon last year’s NOA, which recommended a new offshore transmission route between Suffolk and Kent and a new circuit from Bramford to Twinstead. This year, the analysis continues to show the need for the links as well as three further new onshore transmission route circuits across the south east coast from Norfolk to Kent to alleviate increased network constraints.
National Grid ESO detailed how its analysis shows that in order to increase use of renewable power and achieve lower wholesale prices to provide maximum benefit to consumers, an interconnection capacity ranging from 16.9GW to 27.7GW between the GB and European markets by 2040 will be needed. This is based on the four scenarios in the ESO’s Future Energy Scenarios, which have informed the NOA.
Interconnectors are “a key source of additional electricity system flexibility”, the ESO said, pointing to how they help to reduce renewable energy supply curtailment through exporting the excess intermittent renewable electricity and reduce the need for electricity storage by importing electricity when intermittent renewable electricity levels are too low to meet demand, the ESO said.
Writing in the foreword of the NOA, Julian Leslie, head of networks, said: "The future energy landscape is uncertain, and the ESO’s recommendations make sure the GB transmission network is fit for the future.
"These recommendations are imperative for us all to address the ‘energy trilemma’ of secure, sustainable and affordable energy."