The programme, announced alongside the company's full-year results on 14 May, is the largest capital commitment in National Grid's history. It follows a record £11.6bn of capital expenditure in the prior financial year and arrives as the UK government pushes for a decarbonised electricity system by the 2030s, according to its Clean Power 2030 plan.

Revenue fell 4% to £17.6bn from £18.3bn, which the company attributed to storm-related costs and the divestment of its renewables arm and US grain liquid natural gas business, as reported in its annual results. Pre-tax profit, however, rose to £4.2bn from £3.6bn. Earnings per share climbed 8% to 78p, and the full-year dividend was set at 48.9p, up 3.8% and pegged to UK inflation. Shares stood at 1,297p on the day, up 11.9% year-to-date.

Where the £70bn is going

The headline figure splits three ways. Roughly £31bn is earmarked for UK electricity transmission, covering capacity expansion to absorb the surge of offshore wind, solar and nuclear generation expected this decade. A further £17bn is allocated to New York and £12bn to New England, with around 60% of the US spend flowing directly into National Grid's own network assets, according to the company's results statement.

The UK portion is the most consequential for domestic businesses. National Grid described it as the foundation of a decarbonised electricity network by the 2030s. The company expects UK electricity transmission revenue to rise by approximately £850m in the coming financial year, with the new regulatory settlement doing, in the company's framing, much of the heavy lifting.

In the US, New England top-line growth of around $450m is forecast, driven by rate resets but partially offset by the costs of the expanded build-out, according to the results. New York is expected to follow a similar trajectory.

Zoe Yujnovich, who became chief executive earlier in the year, said the company was:

"Embarking on the largest investment programme in our history… to modernise and expand energy networks across the UK and the US Northeast, networks that underpin economic growth, strengthen energy security and enable the transition to a cleaner, more flexible energy system."

The group expects a 10% uplift in returns from its asset base by the 2030/31 financial year on the back of the programme.

What RIIO-T3 changes for grid access

The UK spend is underpinned by Ofgem's new RIIO-T3 price-control framework, which formally replaces the RIIO-T2 settlement from 2026. RIIO-T3 clears the way for heavier capital expenditure in electricity transmission by resetting the allowances that determine how much National Grid can invest and recover through regulated charges.

For SME operators, the framework matters because it sets the terms under which new grid capacity is funded. A more generous capital allowance, in principle, accelerates the physical build-out of substations, cables and overhead lines that stand between a planning consent and an energised connection.

The practical test is whether this translates into shorter connection timelines. Businesses across manufacturing, logistics and the data-centre sector have reported multi-year waits for new grid connections, a bottleneck that has hampered site-selection decisions and delayed expansion plans since the 2022 energy shock. The UK government's grid-connection reform agenda is designed to address this queue, but the reforms depend on the physical network keeping pace with demand.

National Grid's £31bn commitment puts capital behind that ambition. Whether Ofgem's regulatory timetable and the company's procurement pipeline can convert spending approvals into live infrastructure within the five-year window remains the critical uncertainty.

The supply-chain and workforce ripple effect

A capital programme of this scale does not stay within one balance sheet. National Grid's own statement flagged the creation of "thousands of jobs" across its markets, a message aimed squarely at Westminster, where ministers have pressed infrastructure operators to demonstrate the employment dividend of the green transition.

For SMEs in construction, civil engineering, cable manufacturing, specialist electrical contracting and professional services, the programme represents a sustained pipeline of work rather than a single procurement cycle. The prior year's £11.6bn spend already stretched supply chains; a five-year commitment at even higher annual run-rates will intensify demand for skilled labour and specialist materials.

Three areas are likely to feel the effect most directly. First, high-voltage electrical engineering, where the UK already faces a well-documented skills shortage. Second, civils and groundworks contractors in regions hosting new transmission corridors, particularly in Scotland and eastern England where offshore wind connections concentrate. Third, professional services firms providing environmental assessment, planning support and project management.

The risk, familiar from other large infrastructure programmes, is cost escalation. If labour and materials markets tighten faster than National Grid's procurement assumptions, the regulated cost base rises, and those costs ultimately flow through to consumer and business energy bills via network charges.

What SME operators should watch next

The headline numbers are large, but the details that matter to individual businesses will emerge over the next 12 to 18 months as RIIO-T3 implementation begins and the government's connection-reform proposals move from consultation to practice.

Connection-queue reform. The Department for Energy Security and Net Zero has been consulting on changes to the order in which projects receive grid connections. Businesses planning new sites or capacity upgrades should track whether the reformed queue prioritises "shovel-ready" projects, which would favour operators with planning consent already in hand.

Network-charge trajectory. Ofgem's RIIO-T3 settlement determines the allowed revenue National Grid can recover. A £31bn UK build-out, even spread over five years, implies a step-change in transmission network use-of-system charges. The precise impact on bills will depend on Ofgem's final determinations, expected in the coming regulatory cycle.

Regional capacity maps. National Grid publishes data on available grid capacity by region. SMEs making site-selection decisions, particularly in energy-intensive sectors such as manufacturing, cold storage and data hosting, can use these maps to identify where new capacity is scheduled to come online earliest.

Supply-chain procurement rounds. Firms positioned to bid into National Grid's supply chain should monitor its procurement portal for framework agreements linked to the RIIO-T3 programme. Early engagement in framework competitions tends to secure better terms and longer contract durations.

None of this guarantees faster connections or lower costs in the short term. Capital programmes of this magnitude take years to translate into operational infrastructure. But for the first time since the energy crisis, there is a funded, regulated plan with specific numbers attached. That is a material change in the planning environment for any business whose growth depends on access to reliable, affordable electricity.