The government has created a new publicly owned investor in Britain's electricity grid without yet setting its budget for the long term or identifying the first infrastructure project it will fund.
Great British Grid will sit within Great British Energy and invest public capital alongside private investors in new electricity network infrastructure. Ministers say it will increase competition, speed up grid expansion and help lower costs for households and businesses.
The costs of setting it up will come from Great British Energy's existing budget. The government says funding for the new remit over the long term will be decided at a future Spending Review. The launch announcement gives no figure for the amount of capital Great British Grid will eventually control and does not quantify how much its investments are expected to reduce household bills.
The new body will not take over the existing transmission networks or replace the National Energy System Operator. Ofgem will continue regulating the private network companies, while Great British Grid will be able to invest alongside them and compete for some future transmission projects as competitive tendering expands.
The market it is entering is unusually large. Ofgem estimates transmission owners could invest up to around £70 billion between 2025/26 and 2030/31, although much of that spending remains subject to further regulatory approval. The National Audit Office warned in September that delivering the required upgrades by 2030 will be very challenging, with risks in planning, the supply chain and access to the system already affecting timetables.
There is an economic case for spending heavily on the grid. Renewable generation has grown faster than transmission capacity in some parts of Britain, leaving the system unable to move all available electricity to where it is needed. Consumers ultimately bear both the cost of network investment and the cost of managing those constraints. Ofgem says the coming investment is intended partly to reduce those future constraint costs.
The government has not yet separated the effect Great British Grid itself is expected to have from the wider network programme.
The 29 September announcement also points to more than 300GW of speculative capacity being removed from the connections queue and to plans allowing more businesses and developers to build their own connection infrastructure. Those reforms are separate from the creation of Great British Grid. The government says it is already working with NESO and Ofgem on the queue changes, while the reform allowing them to build their own connections is being brought forward alongside the new body.
Great British Grid is being placed inside a public energy company that is itself still building its investment portfolio.
Great British Energy was incorporated in October 2024 and received its statutory operational mandate in May 2025. Its first audited accounts cover the period to 31 March 2026. They show £14.2 million of operating expenses, including £7.9 million of staff costs and £3.8 million of professional services, against £62,000 of other income. The company reported a £14.1 million loss for the period.
Those figures largely reflect the cost of establishing the organisation rather than losses on unsuccessful energy projects. Great British Energy says the period was spent putting governance, systems and investment capability in place. Costs incurred between incorporation and Royal Assent were retained by the Department for Energy Security and Net Zero and do not appear in the company's own financial statements.
At 31 March, Great British Energy held £9.2 million of assets, including a £5.8 million investment in Highland Wind Limited, the company developing the Pentland floating offshore wind project, its first strategic financial investment. Against that, the company reported £16.8 million of liabilities, putting it in a net liability position of £7.6 million. The accounts attribute most of that to the mechanics of its funding structure: £18.7 million had been drawn down from its capitalisation facility by the reporting date, of which £6.6 million had been converted to equity, leaving £12.2 million recorded as an outstanding facility balance rather than capital paid in.
The company had no directly employed staff at the reporting date. Its workforce of 121 consisted of DESNZ staff, civil servants on loan, secondees and contractors.
That snapshot should not be confused with the much larger funding programme attached to the Great British Energy name.
The 2025 Spending Review committed more than £8.3 billion across Great British Energy and the separate Great British Energy-Nuclear company over this Parliament. Great British Energy's accounts say up to £5.3 billion is expected to be made available to the main company between 2025/26 and 2029/30 under its capitalisation scheme covering several years.
The company's strategic plan sets targets for 2030 rather than describing assets already owned. It intends to establish a portfolio delivering at least 15GW of generation and storage capacity, mobilise £15 billion of private finance, support more than 1,000 local and community energy projects and fund projects supporting at least 10,000 jobs. It says the portfolio should be generating income by 2030 and be on a path towards profitability across the company.
Great British Energy is also associated with a £255 million solar programme for the public sector covering around 250 schools, around 260 NHS sites and military sites. Those installations are real spending and some are already operating. In March, the government said the first 100 participating schools had completed installations.
The figures measure different things. The £5.8 million in Great British Energy's March balance sheet is a direct financial investment owned by the company. The £255 million solar programme is public funding for installations across public sector sites. The £8.3 billion figure is a funding commitment over several years shared between Great British Energy and Great British Energy-Nuclear. Treating all three as though they represent the same kind of public energy asset would give a misleading picture of what taxpayers currently own.
That distinction becomes more important with Great British Grid because the government intends the new body to invest directly in transmission infrastructure.
The launch announcement does not specify how those investments will be structured. It does not identify the first project, the size of the public stake Great British Grid might take, the return expected on public capital or the share of future network revenues that would flow back to Great British Energy.
Great British Energy's existing strategy is clearer about its wider commercial ambition. It says the company intends to own and operate assets, invest on commercial terms and reinvest returns from publicly owned energy infrastructure.
Great British Grid could therefore eventually give taxpayers a direct financial stake in infrastructure that consumers already pay for through their electricity bills. Whether that produces lower overall costs will depend on the projects chosen, the cost of financing them, construction performance and the returns required on the public money invested.
Ofgem has already stressed that the coming transmission programme will ultimately be paid for by consumers and that its job is to prevent unnecessary or inefficient investment. The NAO says stronger oversight and transparent monitoring will be needed if the expansion is to provide value for money.
For Great British Grid, those tests cannot yet be applied. The government has created the investor and set out the role it wants it to play. Its budget for the long term will be decided later, its first investment has not been announced, and the launch documents contain no quantified estimate of the household bill reduction attributed specifically to Great British Grid.