Today’s announcement of Great British Grid puts electricity networks in the spotlight. Whatever the detail turns out to be, it is a welcome moment to talk about the part of the energy system I care most about, and about the question every bill payer should be asking: what does it cost to build the grid, and what does it cost not to?
Stand directly beneath a transmission pylon and look up. The steelwork folds in on itself, square inside square, braced in every direction and carrying conductors that most of us never give a second thought. It is one of the most familiar structures in the British landscape and one of the least noticed. Yet almost everything the energy transition promises has to pass through it.
What was announced
The government has announced Great British Grid, a new publicly owned body within Great British Energy that will invest public capital alongside private investment in electricity network infrastructure. It is designed to complement, not replace, the existing system: network operators keep their roles, Ofgem remains the independent economic regulator and NESO continues to operate and plan the system.
Alongside it come two practical reforms. Self-build connections will be expanded, so developers and businesses can build their own connections rather than waiting for a network company; similar reforms in Ireland cut connection times by up to 11 months. Competitive tendering of transmission projects will also be accelerated, with Great British Grid able to compete alongside others. This builds on the connections reform already under way with NESO and Ofgem, which is removing more than 300 GW of speculative capacity from the queue.
Start-up costs will come from Great British Energy’s existing budget, with the longer-term funding left to a future spending review. How much difference it makes will depend on that funding, which projects it takes on and how it sits alongside the regulated companies. Those are fair questions, and the debate on the model will run its course. My interest is in why the grid needs this attention in the first place.
The grid is the transition
I first wrote about transmission and distribution in 2021, and followed it with a closer look at the high-voltage transmission network and the companies that own and run it. The core point has not changed. Our grid was built for one-way flows from a relatively small number of large power stations, often sited close to demand. The system we are now building looks very different.
Generation is moving to where the wind blows and the sun shines, often far from where people live. Demand is growing and changing shape as heat pumps, electric vehicles and new industry connect, and as data centres ask to plug in at a scale that would have seemed remarkable a few years ago. When I asked whether the future was bright for the UK’s grids in 2024, the scale of what was needed was already clear. What has become clearer since is that the network, more than generation, is often the thing that sets the pace.
Networks are also central to resilience. Robust wires, physical redundancy and the ability to reroute power are what stop a local fault becoming a regional problem.
Paying now or paying later
This is where the conversation gets difficult, and where I think it deserves more balance than it usually gets.
Grid investment is not cheap, and it shows up on bills. Under Ofgem’s RIIO-3 price control, which began in April, around £90bn of investment could flow into transmission and gas networks by 2031, with more than £70bn potentially needed in electricity transmission alone. Ofgem estimates network charges for a typical dual-fuel household will rise by around £108 a year by 2031.
But that is only half the ledger. Ofgem also expects that investment to reduce other parts of the bill by around £80, as the system becomes more efficient, leaving a net increase of about £30 a year. The biggest of those other costs is constraints: when the wires cannot carry power from where it is generated to where it is needed, wind farms are paid to switch off and other plant is paid to switch on. NESO reported thermal constraint costs of £1.7bn in 2024/25, up 64% in a year, and has warned that total balancing costs could peak at around £8bn in 2030. Bringing critical network projects forward could save up to around £4bn in that year alone.
Neither number tells the whole story on its own. Build too little, too late, and we pay through constraint payments, stalled connections and lost investment. Build inefficiently, or in the wrong places, and we pay through higher network charges for decades, because these assets last forty years or more. The cost of capital matters too: a small change in financing costs on tens of billions of pounds makes a real difference to what consumers eventually pay.
So the goal is not to spend more or to spend less, but to spend well. That means building what the system needs, in the right order, at the lowest sustainable cost, and spreading that cost fairly across the generations who will use the assets. It is the same long-term affordability question I explored in my recent post on the clean power debate, and the flip side of the issue I stumbled into with one last gas pipe: networks are built for the long run, and somebody always pays both to build them and to retire them.
What I’ll be watching
A few things will tell us how much Great British Grid changes in practice. First, whether it adds delivery capacity, not just capital: supply chains, skilled people, planning and consenting are as much a constraint as money. Second, how it fits alongside the regulated model, so that competition improves value without unsettling the private investment the grid will still rely on, an area that I focus on a lot in my day to day. And third, whether distribution gets the same attention as transmission. The lower-voltage networks under our streets are where heat pumps, EV chargers and rooftop solar actually connect, and the next distribution price control from 2028 will matter just as much. The distribution contribution to the energy transition should not be underestimated.
Looking up
Pylons rarely make the headlines, and the people who design, build and operate our networks rarely get the credit. Announcements like today’s are a chance to change that. Whatever form delivery takes, the case for the grid is simple: every clean electron, every new heat pump and every new factory has to travel through it. Look up next time you pass beneath one of those steel towers. That is where the energy transition is really being built.
