Is the UK’s Great grid upgrade falling behind? How can it get back on track?

The Great Grid Upgrade is a £70bn programme to modernise the UK’s pylons, overhead lines and substations. While it runs behind schedule, the country pays for the shortfall in constraint costs. This is the price associated with the lack of grid capacity to utilise renewable energy sources. In 2025-26, this cost £1.9bn and the NAO said this could rise to £7.8bn by 2030. 

Transmission owners will need to quadruple their annual spending on upgrades and Gareth Davies, head of the NAO, said the planned upgrades would “Test systems not designed for activity at this pace or scale”. 

If the money is committed and the need is agreed, what is actually holding up the build and how can we progress?

What government can do

1. Planning reform: Streamline the planning and consenting process. 
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   Transmission projects can spend a long time getting permission, sometimes as long (or longer) as they take to get built. With the NAO reporting that 64 of 80 projects are still outstanding and the deadline is 2030, this could mean that a large amount of remaining time will be spent awaiting sign-off rather than construction. You can’t speed up delivery if you don’t have consent to build. 
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   One UK transmission team used Sensat to compare siting options and found an £18m difference in earthworks cost between them, before anyone had been to site. Route studies, survey, design and consenting all have to be paid for while the asset is still in proposal - and the decisions taken in that window set what the build costs.
   

2. Integrated infrastructure planning: Ensure that national and regional infrastructure assets are planned together. 
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   The NAO found that some projects are already forecast to run over the 2030 deadline, which means new generation may connect before the grid upgrades that support it are finished; "It is important to minimise this gap, as delays will increase project and constraint costs and postpone the benefit of achieving clean power," the NAO said.
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   When generation, storage, demand connections and network reinforcement are planned and consented in isolation from one another, delays are common. As well, every new connection is approved on its own, rather than against the capacity of the network that has to carry it. Planning them together helps narrow the gap.

What asset owners can do.

1. Digitise their assets. You cannot make decisions about a network you can only see in drawings, site reports and someone's memory of a site visit two years ago. Most asset owners already hold an enormous amount of information about their site, survey data, design files, condition records, imagery, but if it’s held in different systems, they can’t utilise the technology to make the decisions. Asset owners should see themselves first and foremost as a data company, then an asset owner, so they can take full advantage of the technology and realise the efficiency gains.
2. Data must be readable against the real world. Once the information exists, the question becomes what you can do with it. Spatial intelligence understands physical constraints in the real-world and turns a data estate into decisions. It lets a team test a route or a substation siting against the actual ground, its constraints and its neighbours, before committing to it. And it moves risk identification from construction, where it's expensive, to design, where it's much cheaper. Not only is it cheaper, but it accelerates the delivery - finding the hazards earlier.
3. Information must be visible to everyone. Speeding up initial decision making doesn't mean as much if the evidence behind a decision can't be shown to the people who have to approve it, whether that’s internal gate reviewers, Ofgem, landowners or the public. A deferred gate adds time and money in rework, so being able to show the decision, in context, is the difference between an approval and a delay.

Conclusion

The NAO's verdict is that value for money now depends on delivery. There are 64 projects outstanding and the deadline is 2030.

So we need pace, and much of that is before construction, in consenting, optioneering, design review and the evidence that gets a scheme through a gate. That doesn't need new funding or new legislation to move faster. It needs teams to be able to see all their data in one place, so they can make informed decisions.

This is the problem Sensat was built to solve. Bringing designs, surveys, imagery and constraint data together against the real landscape, so a delivery team can test an option against the actual ground before committing to it, catch the problem in design rather than in construction, and show the reasoning to anyone who has to approve it.

It's already having an effect. At National Grid, decision turnaround went from 35 days down to 5.

The Great Grid Upgrade is an enormous programme that impacts the UK, so it’s right to bescrutinised. Successful teams will be the ones who can show exactly why they built what they built, where they built it.

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Sensat is the infrastructure intelligence platform that gives delivery teams real-world project visibility. Spot project risks early. Deliver safely and with confidence.

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