2026 People's Choice Award

In 1991, a few people founded the energy cooperative Ecopower around a kitchen table in this mill. Today Ecopower has more than 73,000 members, and the mill where it started heats itself entirely from the river that flows beneath it. The same river turns the turbine that powers the heat pumps and provides the heat they upgrade. Even the waste heat of the turbine’s generator and gearbox is recovered. River, mill and heat network work together as one closed local energy loop, with no fossil fuel, no grid dependency for the heat and nothing visible on a heritage site. It proves that aquathermal heat pumps can decarbonise the existing buildings that are hardest to reach, collectively and owned by citizens. Europe has thousands of mills, moats and riverside communities that could follow.

A heat pump installer can have the equipment, tools and training needed for a job and still be held up by one unanswered technical question. When that question reaches the manufacturer, it often joins a queue for the same small group of experts. This project addresses that everyday constraint on heat pump deployment. At Solvis, installers can consult the manufacturer’s knowledge directly. At Inventum, service and sales teams can use that knowledge while speaking with customers. The work has already supported thousands of installer questions, and Inventum’s evaluation indicates substantial potential to release expert time. The innovation also extends beyond answering the immediate question. When the documentation falls short, the question reveals what needs to be improved. Specialists can capture the missing explanation so that the next colleague or installer benefits from it. Two manufacturers in different countries demonstrate how this approach can serve both internal support teams and external installer networks. It starts with documentation manufacturers already possess and improves through the questions people ask. The wider impact is on Europe's energy transition. According to the European Commission, an estimated 750,000 additional installers are needed to scale heat pump deployment and meet the EU's 2030 climate goals, while at least 50% of existing installers will need reskilling. Against this enormous workforce challenge, making better use of existing expertise is just as important as training new professionals. By reducing time lost searching for information, avoiding unnecessary support calls and helping installers resolve problems faster, Chapter enables the existing workforce to work more efficiently and support more heat pump installations. This helps ease pressure on an already stretched sector and removes a practical bottleneck to the electrification of heating. Chapter deserves recognition for making specialist knowledge more accessible and reusable across the heat pump service chain. By helping the people already working in the sector do more with their time and expertise, Chapter contributes to accelerating the energy transition without placing even greater demands on an already constrained workforce.

What is surprising about Cold Air Distribution is not simply that a heat pump heats and cools a Passive House—it is how much of the conventional HVAC system the right heat pump can make unnecessary. The Ecoforest R290 air-to-water heat pump can produce approximately 2°C chilled water for cold-air cooling, provide space heating, and generate domestic hot water above 65°C. This unusually broad operating range allows ventilation air already required for healthy indoor conditions to become the building’s heating and cooling distribution system. Instead of adding equipment, CAD asks how much can be removed. But the project is also designed to answer a bigger question: how much HVAC capacity do ultra-low-energy buildings actually need? Five Canadian pilot buildings are becoming living laboratories. For two years, heat meters, electrical circuit monitors, indoor and duct sensors, airflow operating data and on-site weather stations will measure what is happening inside the buildings, how the systems respond, and the real outdoor conditions driving those loads. This creates something still lacking in Canada: detailed real-world data connecting weather, occupancy-related internal loads, HVAC operation and actual heating and cooling loads in Passive House buildings. This project therefore combines heat-pump innovation with evidence—not just demonstrating a new system, but generating the knowledge needed to design simpler, smaller and more affordable heat-pump-based mechanical systems at scale.

This project is innovative because, for the first time in Paris, Panasonic successfully replaced an oil boiler with 2 BIG Aquarea T-CAP heat pumps installed in a cascade configuration. This solution has decarbonized the building’s heating system while providing a more cost-effective heating solution. Thanks to the T-CAP technology (wich maintain heating even with low temperatures outside), residents’ comfort has also been significantly improved. The ageing hydraulic system meant that heating performance was less effective in the apartments located on the upper floors. Now, even tenants living on the fifth floor benefit from efficient and comfortable heating.

DACS-HW has moved grid flexibility from theory to reality. At Intergas, efficiency has always been part of our DNA. We became a market leader by developing some of the most innovative and efficient gas-fired boilers in Europe. Today, we are applying that same drive for innovation to heat pumps. The challenge, however, has changed. In the past, efficiency was about reducing energy consumption. Today, it is increasingly about making the smartest use of scarce grid capacity. DACS-HW proves that the next generation of heat pumps can do more than heat homes efficiently; they can actively support the electricity system. In the age of electrification, the most efficient heat pump is not the one that consumes the least electricity, but the one that creates the most value from every kilowatt available. DACS-HW makes that vision a reality.

AIGUATERM offers an innovative approach to decarbonising heating and cooling by combining a mature and reliable technology—the heat pump—with thermal resources already available within cities. Its main innovation lies in using existing urban infrastructure without affecting its original function, reducing the need for major new infrastructure and limiting additional investment. In Valencia, the project demonstrates this concept by using a secondary non-potable water network as a heat source and sink. The same approach can be extended to other water-related urban infrastructures, providing cities with a practical, low-impact and highly replicable pathway for the energy transition.

What makes this project special is that an existing high-temperature residential building was decarbonised without replacing its radiators, without rebuilding the hydronic heating system, and without installing a new low-temperature distribution system. The NIK Systems transcritical CO₂ heat pump was integrated in parallel with the existing gas boilers. Since commissioning, the gas boilers have not been required for normal operation. The system supplies approximately 70–80°C water for space heating and domestic hot water. This represents an extremely demanding operating condition for a heat pump and, in particular, for a transcritical CO₂ system, because very high supply and return water temperatures normally make it extremely difficult to maintain high efficiency. What is especially important is that the high COP was achieved specifically at these demanding high-temperature operating points. During recent optimised operation, the system demonstrated COP values reaching approximately 4.5 while operating with very high supply and return water temperatures. This result demonstrates the effectiveness of NIK Systems’ proprietary transcritical CO₂ system architecture and control strategy, and shows that R744 can be used not only for domestic hot water, but also for highly efficient high-temperature space heating in existing buildings. The project therefore challenges the common assumption that existing buildings with high-temperature heating require major renovation or complete conversion to low-temperature heating before fossil-fuel boilers can be replaced by heat pumps. Using natural refrigerant R744, the project demonstrates a practical and scalable pathway for decarbonising a large part of Europe’s existing high-temperature building stock

STORO is an innovative heat pump water heater designed to redefine how domestic hot water systems integrate into residential spaces. The project addresses two key challenges: reducing energy consumption and CO₂ emissions, while overcoming the space and visual impact of conventional hot water systems, especially in modern and historic buildings where outdoor units may be restricted. STORO combines an R290 double-duct heat pump with a Phase Change Material (PCM thermal battery, achieving high energy density in a compact footprint comparable to a standard dishwasher. Measuring 595 × 550 × 850 mm, it can be fully integrated into standard kitchen cabinetry or installed as a free-standing unit. By comparison, a conventional heat pump water heater providing a similar amount of hot water typically uses around 300 litres of storage and can be approximately 1.70 m high. The PCM storage enables 230 L of mixed hot water (V40), with target Class A+ efficiency and a nominal COP target of 3.1. Smart Grid and photovoltaic optimization functions use the PCM as a thermal battery, storing renewable energy for later use and reducing grid consumption. Multiple air-source configurations increase installation flexibility and energy efficiency. STORO transforms the heat pump water heater from a conventional technical component into a compact, connected and sustainable household appliance designed to integrate naturally into the home.