604 GW of grid capacity is contracted and not built.

On 13 October 2026, NESO's transmission entry capacity register held 2,225 rows. 385 were marked built. The other 1,840 hold a contract to connect to the transmission network and are not yet built. Their capacity adds up to 604 GW.

Great Britain's peak demand in 2025 was 45 GW, according to Ofgem. The number does not mean the country will build 604 GW. It means 604 GW of projects hold a place in the line, and every project behind them has to plan around it.

What the number includes

The register lists generation, storage and interconnectors with a contract to connect. Each row carries a capacity, a connection site, a date and a status. Batteries, solar, wind and gas sit side by side. The register also records which projects hold a Gate 2 offer under the connections reform: 107 rows not yet built carry one, 15.4 GW in all.

How we added it up

Some projects connect in stages, and each stage has its own row: 241 of the rows not yet built are stages of a larger project. We added the capacity each row adds, not the running total, so no stage counts twice. Hybrid sites sit in one row: 752 rows not yet built, 262.7 GW, combine more than one plant type, such as solar with a battery. The 604 GW total is arithmetic on the rows as published. It measures the queue. It does not measure the future grid.

Which dates have already passed

97 projects that are not built carry a connection date before 13 October 2026. Together they hold 16.3 GW. Some will connect late. Some will never connect. Anyone planning around them needs to know which is which, and the register alone does not say.

Why it matters now

The remaining Gate 2 Phase 1 offers are due on 31 October 2026. Ofgem's consultation on connections data closes on 6 November, and its respondents call today's capacity registers inaccurate, incomplete and out of date. The National Audit Office found that the share of projects offered a connection at the date they wanted fell from about 64% to 16% between 2019-20 and 2023-24.

Savitram keeps every row of the register as a record, with its gate, status and date, and every other project at the same substation beside it. When the register changes, the record shows what moved.