Britain will pay for air conditioning, as long as it also heats

The machine that runs both ways

Britain is preparing to hand out grants of 2,500 pounds for air conditioning units, on one condition: they must heat as well as cool [1]. These are air-to-air heat pumps, and they are the same machine as the winter kind, run backwards.

The rules only just caught up. Until recently a heat pump that also cooled needed planning permission, because permitted development rights said the unit had to be solely for heating. That was changed last year to allow cooling [1].

Of Britain’s 358,000 heat pumps, about 323,000 are air-to-water systems, which push warm or cool water round radiators, according to certification-scheme figures [1]. Air-to-air units use wall-mounted fans instead. They cost around 4,500 pounds to fit in a flat or small house, against roughly 12,000 pounds for the water kind [1]. Plenty of British households have already bought cooling quietly, in the form of portable air conditioners kept out of sight in bedrooms [3].

It works. At the University of Salford’s Energy House 2.0, a climate-controlled test chamber, researchers ran a heat pump with fan coils inside a full-size house. With the lab set to 32C, rooms held between 19C and 24.9C. Running round the clock cost 2.50 to 3 pounds a day [1]. Prof Lubo Jankovic, who led the work, said reversible heat pumps can help protect homes against overheating. He added that designing a system for both jobs at once still needs to be solved [1].

The Climate Change Committee is the government’s statutory climate adviser. It has said hotter heatwaves could leave 92% of existing British homes overheating by 2050, with drawing the curtains no longer enough [1].

The summer that changed the argument

Cooling stopped being a foreign problem this year. Britain’s Environment Agency declared over 70% of England in drought. Reuters estimated 204 million people, 56% of western Europe’s population, would see temperatures at least 5C above normal for the date [21]. Roughly 27 million people are under hosepipe bans or other water restrictions [6].

France entered its fifth heatwave of the summer. Fires forced more than 1,000 people out of the Croatian town of Omis and emptied the German village of Gey, all 1,800 residents. In Spain, troops carried artefacts out of a monastery in Huesca as flames advanced [4]. UK temperatures passed 35C several times, and the heat has been linked to thousands of deaths and roughly 4bn pounds of lost output [5].

In east Asia the same summer went further. Yangsan in South Korea hit 42.5C on 2 August, the highest since records began in 1904. At least 31 people died, along with more than 900,000 livestock and 1.4m farmed fish. Potatoes came out of the ground soft, one farmer said, like boiled ones [7]. In France, Champagne’s growers started picking on 12 August, the earliest harvest since records began, after spring frost had already destroyed about 30% of the crop [8].

That is the backdrop to a British political row. Reform’s deputy leader, Richard Tice, told a press conference it was arrogant to try to stop climate change. He urged people to enjoy the warm weather, drawing criticism from nurses and medical bodies [5]. Meanwhile the government has declined to publish its emergency drought plans [16], and campaigners are pressing for cool public spaces and grey-water rules to be treated as urgent [17].

Why the sums still don’t work

Here is the physics that makes all of this worth arguing about. A gas boiler burns fuel and gives you at best one unit of heat per unit of gas. A heat pump gathers warmth from outside air and delivers three to four units of heat per unit of electricity [2].

And here is why that advantage keeps vanishing at the meter. Electricity in the EU costs about three times as much per unit as gas; in Britain the ratio is 4.3 [2]. Much of that gap is tax rather than cost, so a machine three or four times more efficient can still be more expensive to run.

The European Commission has published an electrification action plan aimed at ending that. It would double electricity’s share of Europe’s energy from 23% to 46% by 2040. It would also put a legal duty on governments to cut the household price ratio to no more than 2.5 by 2030. Behind it sits 75bn euros from the European Investment Bank for grids, storage and heat pump manufacturing [2]. The Commission estimates the plan could cut gas imports by more than 70%. That would take up to 260bn euros a year off Europe’s fossil fuel import bill by 2040 [2].

Britain has started closing its own gap. The 2025 autumn budget moved most green levies off electricity bills and into general taxation, trimming the ratio from 4.7 to about 4.3 [2]. Countries with the narrowest gaps already sell around three times as many heat pumps as those with the widest [2].

Upfront cost is the other wall. A heat pump runs to about 10,000 pounds in Britain before grants and close to 30,000 euros in Germany, against roughly 2,500 pounds for a new gas boiler. Labour costs, VAT and a shortage of installers explain most of the difference, not the technology [2]. Britain’s boiler upgrade scheme covers 7,500 pounds of an air-to-water installation, rising to 9,000 pounds for homes off the gas grid [1]. Even so, the consumer group Which? found buyers treat the switch as a high-stakes gamble [1].

Elsewhere on the grid

The wider system is moving faster than the boiler cupboard. Europe’s wind and solar farms are on track to out-generate its gas plants for the longest stretch on record this year. A decade ago gas produced more than twice as much [9]. India crossed a quieter line. Clean sources now hold 331.7 GW of installed capacity against 302.0 GW of fossil, a first. Coal still supplies about 70% of the electricity actually generated [10].

Storage is arriving. Coalburn 1, a 500 MW battery holding 1 GWh on a former coal mine near Glasgow, is now Europe’s largest in operation [11]. In the United States, home battery installations kept climbing after the federal tax credit expired, reaching 673 MW in the first quarter, while rooftop solar and EV sales fell [12]. Of the 368 utility-scale plants that came online in America between January and June, solar led by a wide margin [19].

Demand is arriving faster. In Texas, the queue of large new users wanting a grid connection has grown by more than 200 GW since 2024, mostly data centres and industry. The consultancy Ascend Analytics reckons more than 80% of them will not have matching generation online by 2030 [13]. Global electric vehicle sales rose 9% year on year in July to 1.85m, a fifth straight monthly rise, with Europe covering for weakness in China and North America [20]. And in a laboratory in Nanjing, researchers reported a 24.0% efficiency record for a meter-scale perovskite solar module, verified by TUV SUD [14].

Two decisions still open

Britain’s regulator closed its consultation on the Rosebank oil field and the Jackdaw gas field this week. The 8.7bn pound project off Shetland is being reconsidered after a court found the original approvals unlawful. Campaigners at Uplift point to this summer’s fires; the developer’s chief executive argues domestic production means tax revenue and north-east Scottish jobs [15].

In Washington, the NOAA said it would stop coordinating the Arctic Report Card. That annual environmental summary has run since 2006, covering a region warming about four times faster than the global average [22].

The number that quietly improved

One piece of good news went almost unreported. Emissions from land-use change - clearing forests, draining peat, degrading woodland - have fallen by roughly a third this century, with the drop steepening after 2015. The latest Global Carbon Budget records a statistically significant decline since the late 1990s, and puts 2025 land-use emissions about 32% below their 2000s average [18]. Fossil fuel emissions have not followed. But one large source has genuinely turned.