Summers in Europe are getting hotter. And hotter. And hotter. Europe is, in fact, the fastest-warming continent in the world. So it’s no surprise that in the middle of the year’s fourth heatwave, and while southern Europe is burning, a line like “this is the coolest summer of the rest of our lives” is spreading real anxiety, and reviving old arguments.

Air conditioning is one of the topics catching that anxiety and being argued over. On one side, climate-conscious voices worry that fighting the heat with more AC just adds fuel to the fire: more electricity demand, more heat, higher temperatures down the line. On the other side, people point out that carrying on as usual, in ill-equipped cities, buildings, and homes with no real way to manage heat, isn’t an option anymore. A recent report by the European commission found that 75% of European buildings remain energy-inefficient and quickly overheat in summers. The stakes of which are very concrete: the European mortality monitor estimates that the June 2026 heat wave is responsible for 10.000 deaths.

For this summer edition of Watt’s Next, we’re digging into air conditioning: what’s good about it, what’s bad, and where each side might be getting it twisted.

Back to basics: What’s an AC and how does it work?

Air conditioners are simple machines: a compressor squeezes a refrigerant gas, in doing so, heat is released, that heat gets pumped outside, and the now-cold refrigerant loops back in to soak up more heat from your living room. That’s it. That’s the whole trick, and it’s the same one as in a fridge, a wine cooler, and -importantly- in a heat pump.

But not all ACs are the same. On one end: the €300-€1,400 single-room units, split units, portable “monobloc” boxes, the ones sold out within hours of a heatwave warning. They do one job: cool down one room. They dump their waste heat straight out a window into the street, and when winter comes, they sit in a cupboard doing nothing.

On the other end: integrated, air-to-air heat pump systems, wired into a building’s heating system, that cool homes in July and heat them it in January.

One of these is a seasonal gadget. The other is a decarbonised heating and cooling system that happens to double as an appliance.

Find out more about the real decision making and installation process of a heat pump in your home here and here.

So what’s the problem with ACs?

The debate around ACs can be summed up around two arguments:

1. Electricity demand – won’t millions of new units strain a grid already under pressure?
2. Heat clusters – don’t ACs just export the heat problem, turning already baking cities into ovens by pumping warm air onto the street?

On electricity demand

Europe isn’t building a heat-pump culture the way the US built an always-on-21°C culture. Nobody here is planning to hold their living room at a constant temperature twelve months a year. ACs get switched on when it’s actually needed, during heatwaves and extreme heat. And in this regard, heatwaves have a useful feature: they’re sunny and often windy, which is exactly when solar and wind generation are running hardest. The spike in demand and the spike in clean supply, tend to arrive hand in hand. For the couple exceptions, those humid days covered by cloudy skies or burning nights that follow a suffocating day, a home battery can help smooth out discrepancies. Find out more about home batteries.

Push this a step further and it gets interesting. Pair a heat pump with a smart meter and dynamic tariffs, and a heat pump does not stress the grid by creating more demand, but becomes a flexible grid asset. Run it hard in the early afternoon, when solar is flooding the system and wholesale prices are near zero, and you’re not straining the grid, but you are helping balance it, soaking up generation that would otherwise go to waste or get curtailed. Time it well, and cooling gets both cheaper for the household and useful for the system.

Episode on smart meters of can Adrian electrify his home coming soon. Stay tuned here.

On heat clusters

Yes – a room full of individual units, each blasting hot air into an alley, raises the temperature of that alley (estimated 2-3°C). This isn’t a reason to abandon cooling. It’s a reason to stop treating cooling as something you only do after the heat gets in. Shade a street before you shade a room: trees along pavements, external shutters rather than indoor blinds, awnings that stop sun hitting glass and turning a window into a greenhouse. Passive design isn’t a nostalgic add-on for people who dislike machines,  it’s the thing that determines whether your AC is fighting a losing battle against a building that leaks heat all day, or barely has to work at all.

But circle back to the actual complaint, does cooling your home make the street outside hotter? Locally, briefly, yes, a compressor has to put the heat it removes somewhere, and “somewhere” is usually the alley behind it. But this is a density and design problem, not an indictment of the technology. A handful of individually-vented units on a narrow street is bad practice. Ducting waste heat away from pedestrian level, favouring systems that vent onto rooftops rather than into alleys, and, for anywhere building density allows it,  moving toward shared or district-scale systems that centralise and manage that waste heat rather than scattering it street by street, all address the actual problem without giving up cooling. This isn’t theoretical. Ambient-temperature networks already run on exactly this logic: buildings that need cooling dump their heat into a shared underground loop, buildings that need heat pull it back out with water-source heat pumps, and boreholes or aquifers soak up whatever’s left over. A supermarket’s fridges, a data centre’s servers, a metro station and a block of flats can all be feeding the same loop at once. The same logic scales down to a single building: a standalone cooling unit just throws its heat away outdoors, while a heat pump can route it somewhere useful instead – hot water, a neighbouring building, an industrial process.

Denmark is the proof of concept for the whole idea, roughly two-thirds of Danish households already get their heating from a shared network rather than a boiler in every basement. Copenhagen has simply extended the same logic to cooling, chilling buildings with a district system that draws on cold harbour water instead of running a compressor in every office block.

Summing up

Take the two grievances together and none of them are objections to cooling. They’re objections to cooling done poorly, single-purpose, and badly timed. Run the same technology with an air-to-air heat pump, timed to the hours the grid is already flooded with clean power, installed by someone accountable, and objections can be addressed. The interesting question was never whether Europe should cool its buildings. It’s whether it does so with 7 million disconnected boxes, or with the infrastructure it’s already building for increasingly decarbonised winters.

News from the EA:

• July was marked by the publication of the long awaited Electrification Action Plan (EAP). To make sense of the plan and its impact, the EA published its own explainer. Once it was released, the EA’s board reacted in the quote carousel. A couple days later, we took some time to dig into what the plan entailed and compared it to our 10 tasks in the EAP scoreboard. To read the full reaction, see our press release.

• And in the moments in July where the EA wasn’t preparing for, or reacting to, the Electrification Action Plan, we traveled to Dublin with our chair Paul Kenny from EHPA for the beginning of the promising Irish Presidency of the European Council. See more here.
• Lastly, the EA hosted an intimate roundtable on the fragmentation of the European Energy System to unpack why energy security is inseparable from European competitiveness and autonomy, whether the draft grids package actually closes the gaps it was designed to close, and what a genuinely coordinated European approach would look like in practice, not just on paper.

News from members:

E-Mobility Europe‘s latest EV Bulletin shows a record-breaking June: 275,060 battery electric vehicles were registered across Europe (+39.5% year-on-year). More than one in four new cars sold across Europe was fully electric, confirming the continued acceleration of the EV market. Momentum is spreading across the continent, with several markets reaching new highs. France recorded a 29.6% BEV share, Ireland surpassed the 50% mark (51.2%), and Belgium achieved its strongest-ever monthly volume. Italy also continued its rapid growth, nearly doubling BEV registrations compared to June 2025. The latest figures show that Europe’s EV transition is moving from early adoption to broader market acceleration, with record levels of uptake now emerging across a growing number of countries. Full bulletin available here.

The European Heat Pump Association is highlighting “the one crucial fix for electrification”: the price signal. One of the biggest barriers isn’t the technology itself, but the fact that across much of Europe, electricity is still significantly more expensive than fossil gas – only in Finland and Sweden is electricity less than twice the price of gas. Yet data EHPA supplied to the European Commission’s Electrification Action Plan shows that Member States with the lowest electricity-to-gas price ratios record three times more heat pump sales than those where the ratio exceeds three. The European Commission has accordingly set a clear objective: bring national electricity-to-gas price ratios down to a maximum of 2.5 for households and 2.0 for industry by 2030. Why does this matter? Around half of a household electricity bill reflects the cost of electricity itself, with the rest made up of taxes, levies and network charges – and in many Member States, electricity is taxed more heavily than fossil gas, while fossil fuel subsidies continue to artificially lower the price of gas, weakening the business case for heat pumps and other electrification technologies. Read more and watch the video here.

This summer, EuropeOn – The European Electrical Contractors Association is looking at “what powers your summer”. Behind many summer experiences, there’s one constant: electricity. Electrical installations and devices enable your moments of comfort, convenience, and peace of mind, and electrical contractors are the skilled professionals who install and maintain them. Read more here.

smartEn Smart Energy Europe is spotlighting how industrial demand-side flexibility works in practice, from paper mills and chemical plants to data centres, cement producers and water utilities –  a growing number of energy-intensive industries across Europe are participating in flexibility markets while keeping production running smoothly, showing that flexibility can create value for both industry and the power system. Its latest Smart Energy Talk explores this in depth, drawing on the new Collection of Best Practices for Flexible Energy-Intensive Industries, which brings together 21 case studies from across Europe showing how different sectors are reducing energy costs, supporting grid stability, facilitating the integration of renewable energy, and creating new revenue streams where market conditions allow. The examples show that industrial flexibility isn’t one-size-fits-all, but where the right market frameworks exist, it’s already delivering measurable benefits. Watch the full video to learn more here.

The International Copper Association is holding its Industry Leaders Forum in London on Thursday, 22 October 2026. The copper industry doesn’t stand still, and neither are they. The industry, is at an inflection point, with the energy transition, digital transformation, and the demands of an increasingly urban global population placing copper at the center of one of humanity’s most urgent discussions. ICA is bringing together its members, senior industry executives, and other key personalities in London this autumn for a day of keynotes, panels and conversations that matter. The day runs from a networking breakfast at 8:30 AM, with programming starting at 9:00 AM, at the Hyatt Regency London-The Churchill. Registration is now open here.

Join SolarPower Europe’s flagship back-to-Brussels networking event on 8 September at The Standard Hotel Rooftop. This year’s edition will feature a keynote address from European Commission Executive Vice-President Teresa Ribera and the launch of a new campaign calling for a strong EU renewable energy target for 2040. Bringing together 300+ policymakers, industry leaders and energy stakeholders, Rooftop REconnect offers a unique opportunity to kick off the new political season and discuss Europe’s clean energy future. Register here.

Lastly, WindEurope and Microsoft are launching Hack the Climate, a new AI hackathon bringing together developers, data scientists, energy professionals and innovators to tackle some of the biggest challenges facing Europe’s energy transition. The hackathon will focus on developing AI-powered solutions to improve grid flexibility and maximise the use of renewable electricity. Participants will work with real-world energy data and collaborate with experts from across the energy and technology sectors. Registrations are now open. We encourage everyone to take part and help shape the next generation of digital solutions for Europe’s clean energy system. Find out more and register your team here

This article was originally posted as part of the Watt’s Next Electrification Alliance newsletter. For timely updates subscribe here.