Ofgem and National Gas Move to Avert Winter Supply Crunch

Ofgem and National Gas have published a plan they say will prevent tight gas supplies this winter, a claim both LBC and the London Evening Standard have fact-checked. The short version: the risk of emergency measures, the kind that ask factories to power down and households to cut back, is lower than it was a year ago. The longer version matters more to anyone paying a gas bill.

Security of supply and affordability are different things. A plan that keeps the pipes full does not make the molecules cheaper. The price cap still tracks wholesale gas, and wholesale gas still trades on a market that reacts to Norwegian maintenance schedules, LNG cargo diversions and the weather in north-east Asia. Ofgem’s own cap methodology does not include a supply-security discount.

What the plan actually covers

National Gas runs the National Transmission System, the high-pressure spine that moves gas from terminals and interconnectors to the distribution networks that serve homes. Its winter outlook, which both outlets report on, sets out the assumed supply margins under a range of scenarios: a cold snap, a disruption to a major import route, and a combination of the two.

The fact-check framing is telling. Both LBC and the Evening Standard treat the claim that the plan “will prevent tight supplies” as something that needed testing rather than simply reporting. That is the right instinct. A winter outlook is a forecast, not a guarantee. The margin depends on assumptions about demand, and demand depends on the weather and on price.

What the outlets do not do, because it is not their job, is translate the plan into a household budget. So let us do it here.

What it costs a typical 3-bed semi

A typical 3-bed semi uses around 12,000 kWh of gas a year for heating and hot water, plus roughly 2,900 kWh of electricity. At current capped unit rates, that is about £720–£780 for gas and £800–£860 for electricity, before standing charges of around £60–£70 per fuel. Total: roughly £1,650–£1,750 a year.

Those figures assume the cap holds. They also assume the boiler is working at its rated efficiency. A 15-year-old non-condensing boiler can be running at 70–75% efficiency, which means a third of every pound spent on gas is going up the flue. Replacing it with an A-rated condensing boiler typically cuts gas use by 10–15%, around £75–£115 a year on the figures above at today’s prices, and more if the price cap rises.

The catch is that a new boiler costs £2,000–£3,500 installed. The payback is slow at current prices. That is why the more interesting number for most homeowners is not the boiler’s efficiency rating but the EPC band on the certificate.

The EPC angle the winter plan misses

Minimum Energy Efficiency Standards (MEES) already require a band E rating for new tenancies in England and Wales, and the government has consulted on raising that to band C for rented homes by 2030. Owner-occupiers are not yet bound by MEES, but the direction of travel is clear, and mortgage lenders are already pricing energy performance into affordability models.

A 3-bed semi built before 1980 with cavity walls and a loft is likely sitting at band D. Cavity wall insulation (£500–£1,500) and 270mm of loft insulation (£300–£600) can move a D to a C on their own. Those measures also cut gas use by 15–25%, which is a larger saving than a boiler swap and at a fraction of the cost.

Grants exist. The Great British Insulation Scheme (GBIS) targets homes in bands D–G with a focus on lower council tax bands. ECO4 obliges larger suppliers to fund insulation and heating upgrades for households on means-tested benefits. HUG2, the Home Upgrade Grant, covers off-gas-grid homes in bands D–G. None of these are universal, and eligibility rules vary by council and by supplier. But a homeowner who assumes they will not qualify is often wrong.

Heat pumps and the Boiler Upgrade Scheme

The Boiler Upgrade Scheme offers £7,500 towards an air-source heat pump, administered by Ofgem. Applications are open now and the grant is deducted from the installer’s invoice, so the homeowner never pays it upfront. For a well-insulated 3-bed semi, a heat pump installed at £12,000–£14,000 before the grant lands at £4,500–£6,500 net, roughly the cost of a like-for-like boiler replacement plus a few radiators.

The running-cost comparison depends on the tariff. At a standard variable electricity rate of around 24p/kWh and a gas rate of around 6p/kWh, a heat pump with a seasonal performance factor of 3.0 costs about 8p/kWh of heat delivered, against 6p for a condensing gas boiler. On a time-of-use tariff with cheap overnight windows, the heat pump wins. On a flat standard variable, it does not, yet.

That gap is the honest caveat. The winter supply plan is good news for the grid. It is not, by itself, a reason to rush a heat pump installation before the cold arrives. The reason to act is the EPC band, the grant deadlines and the fact that a boiler that fails in January is replaced at whatever price the emergency installer quotes.

What to do before the heating season

Check your EPC band first, the certificate is free to look up on the gov.uk register and tells you the recommended measures with indicative costs. If you are in band D or below, call your council’s energy advice service and ask specifically about GBIS and ECO4 eligibility; the rules are not intuitive and the council has the local delivery contract.

If your boiler is over 12 years old, book a service now rather than in December. A service costs £80–£120 and will tell you whether the heat exchanger is sound. If it is not, get two quotes for a replacement and one for a heat pump under the Boiler Upgrade Scheme, the £7,500 grant makes the comparison worth running even if you expect to stay on gas.

Finally, check your tariff. If you are on a standard variable, the cap is the default, not the best available. Fixed deals are pricing in a small winter risk premium, but a 12-month fix taken in October locks out the January spike. Compare the standing charge as well as the unit rate, the standing charge has risen faster than the unit rate on most tariffs and now adds £60–£70 a year per fuel.