When Ideology Rules Engineering Chaos Follows

When political ideology and computer modelling are allowed to dictate energy policy without being restrained by engineering reality, chaos follows.

The National Audit Office has now exposed the scale of that chaos, and the bill that will be passed to the public.

Ed Miliband did not create every failure identified by the NAO.

The connect-and-manage policy, missed investment decisions and lack of coordinated spatial planning developed under successive governments.

But Miliband inherited every warning.

He inherited a transmission system already unable to carry all the electricity being connected to it.

He inherited delayed reinforcements, rising constraint payments, an unstable outage programme, shortages of skilled workers and intense international competition for transformers, cables and switchgear.

Instead of stopping and reassessing the system, Miliband accelerated it through Clean Power 2030.

DESNZ Gave the Green Light When Everything Was Red

The NAO found that DESNZ allowed renewable generation to expand faster than the transmission network.Successive governments permitted generating projects to connect before the wider grid was ready to transport their electricity.

Constraint costs consequently rose from £600 million in 2018–19 to £1.9 billion in 2025–26, measured in 2024 prices.

These costs arise because NESO must intervene when the network cannot carry electricity from where it is generated to where it is needed. Generators, often Scottish wind farms , are paid to reduce output, while generators elsewhere , often English gas stations , are paid to increase output.

Consumers pay both sides of that transaction.The NAO says constraint costs could reach between £6.6 billion and £7.8 billion in 2030 if the required grid projects are not accelerated. Without any further network upgrades, the estimate rises as high as £12.7 billion a year.

Those figures do not represent the construction cost of the new network. They are the potential annual cost of operating around a network that cannot transport the electricity produced.

DESNZ knew the grid was constrained. It knew reinforcements were late. It knew planning and supply chains were under pressure.It gave the political green light anyway.

The £70 Billion Catch Up Programme

Ofgem estimates that Britain may need to spend approximately £70 billion on the transmission network between April 2025 and March 2031, expressed in 2023–24 prices.Around £62 billion of that prospective expenditure is intended to increase network capacity.

This is not a minor reinforcement programme. It represents a quadrupling of the historic investment rate. Annual transmission expenditure is expected to rise from approximately £2.5 billion in 2025–26 to more than £11 billion a year between 2027–28 and 2030–31.Yet only £17.7 billion of the possible £70 billion had been approved upfront.

Much of the remainder depends upon staged regulatory decisions because projects are not sufficiently mature for their complete costs to be settled.

That is the real condition of Clean Power 2030.The government has committed to the destination, but much of the infrastructure required to reach it remains subject to design development, planning, procurement, construction and future funding decisions.

Consumers Will Pay More

Even If the Programme Succeeds

The cost will appear directly in household bills.The NAO reports that a typical household paid approximately £44 towards building and maintaining the transmission network in 2025–26.Ofgem expects that contribution to reach approximately £104 by 2030–31—an increase of £60 a year.

Ofgem argues that consumers could still be around £30 a year better off than under the counterfactual in which the network is not accelerated, because the completed projects would reduce constraint costs and dependence on gas.

That comparison must be understood correctly.It does not show that bills will fall by £30. It shows that Ofgem expects the accelerated grid programme to be £30 less expensive for a typical household than allowing the existing constraint crisis to become even worse.

Consumers are therefore being offered a choice between paying for an enormous network expansion or paying still more to operate around the congested system created when generation was connected before the grid was ready.

The public pays under both scenarios.

NESO Pursued the Target Without Proving the Whole System

NESO identified 80 transmission projects it considered essential for Clean Power 2030 and eight additional projects whose acceleration would reduce constraint costs.

But the NAO found that the chosen projects were not the result of a complete whole-system assessment of the alternatives.

Most were selected because they were already in development and appeared most capable of supporting the 2030 timetable.

That is not proof that they represent the best engineering solution, the most secure energy system or the lowest-cost pathway.

A proper whole-system assessment should have compared different combinations of nuclear generation, managed gas, renewable capacity, storage, demand, network construction and regional generation location.

Instead, the renewable generation pathway was largely treated as fixed. NESO was then required to identify the network needed to accommodate it.The electrical destination was chosen first. Engineering was told to catch up.

The NAO also found that the government’s chosen grid programme is not supported by a full business case, complete options appraisal or overall value-for-money assessment.

The government has therefore not demonstrated that this £70 billion prospective programme represents the best way to meet Britain’s energy needs.

Fifty of the Fifty Six Projects Are Already Late Against Need

The project figures destroy any suggestion that this is a mature and controlled delivery programme.Of the 56 ongoing transmission projects considered essential for Clean Power 2030:- 50 are forecast later than the original date at which NESO said the system would optimally require them;- three have no forecast energisation date;- four are expected after 2030;- 32 are off track or face significant risks against their current delivery date;- 24 were still in design, planning or consenting;- 15 remained in scoping or option testing; and- only 17 were in construction by March 2026.Only five of the 56 were labelled on track with no identified project risks.

Even this does not mean those five will arrive when originally needed. The NAO warns that Ofgem’s agreed delivery dates can be later than NESO’s optimal system-need dates.

A project can therefore be called “on track” only because the accepted date has already moved.The label survives. The original programme does not.

Seven Projects Carry Up to £6.7 Billion of Annual Risk

NESO identified seven critical project elements where delay could add up to £6.7 billion a year to constraint costs.

These include Norwich to Tilbury, Sea Link, Eastern Green Link 1 and 2, Yorkshire GREEN, and the Brinsworth–Chesterfield–High Marnham reinforcement.

Our physical audit indicates that Yorkshire GREEN is the only one of these critical elements presently supported by sufficiently advanced construction evidence to justify a credible on-track assessment.

Norwich to Tilbury’s public programme runs to 2031.

Sea Link’s construction programme also runs to 2031.

Eastern Green Link 1 is a genuine construction project, but its expected completion has moved to 2029 against an original system need in 2027.

Eastern Green Link 2 is under construction, but its 2029 date still depends upon the successful delivery of specialist converters, cable manufacturing, marine installation and commissioning.

The Brinsworth–Chesterfield–High Marnham programme missed its original need date. Main construction at Long Lane had not begun, while the detailed programme extended critical electrical works and commissioning through winter 2030.These are not marginal local projects. According to NESO, delay to this small group could expose consumers to costs measured in billions of pounds each year.

Ofgem Delayed Investment and Is Now Reducing Scrutiny

The NAO found that some network projects were not approved when they were first proposed.Some of those reinforcements are now being approved at higher cost during a period of intense international competition for essential equipment and skilled labour.

Having helped delay investment, the regulator is now under pressure to accelerate it.

The NAO says Ofgem changed its risk appetite to prioritise faster funding decisions, where possible, over more detailed scrutiny of project costs and risks.

The reason is clear: delaying projects could increase constraint costs further.

But the consequence is equally clear. Consumers are being committed to an unprecedented network programme while the regulator accepts that speed may take priority over the depth of upfront cost scrutiny.

The public carries the resulting risk.

If Ofgem delays approval, constraint costs may rise.If Ofgem approves immature projects quickly, consumers carry greater construction, procurement and cost risk.This is the trap created by allowing generation policy to outrun infrastructure.The Outage Programme Is Already FailingTransmission infrastructure cannot simply be built beside the existing network and switched on.Projects require carefully planned outages so equipment can be connected, protection systems tested and circuits energised without threatening the security of the electricity system.In 2025–26, NESO handled approximately 23,400 applications for system access through network outages.Around 15,300—roughly two-thirds—were cancelled or rearranged because of changes made by NESO or the relevant transmission owner.

This is one of the most important facts in the NAO report.

Even where pylons, cables and substations are physically progressing, the programme still depends upon access to a live national system that must continue supplying electricity throughout the construction period.Civil engineering progress is not the same as electrical capability.A completed substation building is not an energised substation. A cable in the ground is not a commissioned circuit. A line of new pylons does not increase transfer capacity until the entire connected system has been tested and made operational.Engineering cannot be replaced by a target date in a ministerial announcement.

NGET Was Left to Build the Remedy

NGET did not determine Britain’s generation mix. It did not establish Clean Power 2030. It did not create the policy of connecting generation before sufficient transmission capacity existed.

DESNZ set the political direction.

NESO translated that pathway into network requirements. Ofgem controlled the regulatory approvals and funding framework.

NGET and the other transmission owners were left to secure land, obtain consent, procure equipment, construct the infrastructure, arrange outages, commission the assets and make the system work.

That does not absolve NGET.

Where NGET publishes a date that is contradicted by its detailed construction programme, it must be challenged. Where costs rise, procurement is delayed or physical milestones are missed, the company must be held accountable.But responsibility for delivering the repair must not be confused with responsibility for creating the damage.

NGET has inherited a compressed catch-up programme because generation policy was allowed to run years ahead of the network.

Miliband Saw the Warnings and Accelerated

Ed Miliband did not create every historical failure exposed by the NAO.

But he inherited the evidence of those failures and chose to accelerate the same target-led approach.

He inherited rising constraint costs.He inherited a grid programme in which most projects had not entered construction.

He inherited shortages of equipment and skilled labour.

He inherited a planning system that took years to consent nationally significant infrastructure.

He inherited a network in which the required outage programme was already being cancelled and rearranged on a huge scale.

He nevertheless committed Britain to Clean Power 2030.

That decision made the 2030 date politically fixed while the engineering programme remained incomplete.

The NAO has now revealed the result: up to £70 billion of prospective network expenditure, potential constraint costs of £7.8 billion in 2030 if acceleration fails, a typical household network charge rising from £44 to £104, and critical-project delay exposure reaching as high as £6.7 billion a year.

These figures cover different costs, years and price bases. They must not be added together.But they reveal the scale of the exposure.

Engineering Was the Only Honest Solution

Engineering should have determined the sequence.Britain should first have established the electricity demand it needed to serve. It should then have secured sufficient firm generation to meet peak demand through winter, low-wind conditions, plant outages and import disruption.

Only after that should policymakers have determined the appropriate balance between nuclear, gas, renewables, storage, demand management and network expansion.

Generation locations should have been matched to available transmission capacity. Construction targets should have reflected real planning times, equipment lead times, skilled-worker availability and outage access.Instead, the political target came first.Generation expanded before the network.The network plan followed the generation assumptions.The planning system, supply chain and transmission owners were ordered to conform to 2030.That is not engineering-led energy policy. It is ideology attempting to command a physical system.The National Audit Office has exposed the consequences.

DESNZ gave the green light when the system was showing red.

NESO designed a network around a predetermined political pathway without proving that it was the best whole-system solution.

Ofgem delayed earlier investment and is now reducing detailed scrutiny to accelerate the resulting catch-up programme.

NGET has been left to build the remedy.

Consumers will pay for the infrastructure, the constraints, the delays and the risk.

That is the price of allowing ideology to outrun engineering.

Shane Oxer.   Campaigner for fairer and affordable energy