According to a report by the Japan Refrigeration and Air Conditioning Industry Association (JRAIA) on April 11, 2025, the JRAIA, the Heat Pump and Thermal Storage Center, and the Federation of Electric Power Companies have been working together to promote the adoption of ECOCUTE, a nickname for natural refrigerant CO₂ heat pump water heaters used by electric utilities and water heater manufacturers. Thanks to the understanding and support of customers, the relentless efforts of manufacturers and distributors, and the impetus provided by recent policy support, the cumulative shipments of CO₂ heat pump water heaters (based on JRAIA statistics) have surpassed the milestone of 10 million units as of the end of March this year. We are pleased to announce this achievement.
CO₂ heat pump water heaters, known in Japan as ECOCUTE, are electric water heaters that utilize “heat pump technology” to heat water by harnessing renewable energy in the form of heat from the atmosphere. These heaters are highly energy-efficient and significantly reduce carbon dioxide emissions. Compared to conventional gas water heaters, CO₂ heat pump water heaters produce only about 60% of the CO₂ emissions. Based on certain assumptions, replacing 10 million conventional gas water heaters with CO₂ heat pump water heaters could reduce annual CO₂ emissions by approximately 3.79 million tons.
Heat pump technology is a practical solution for decarbonizing heating needs. To achieve the goal of carbon neutrality by 2050, it is necessary to expand the adoption of CO₂ heat pump water heaters to around 36.5 million units. Furthermore, by using electricity generated from renewable energy sources such as solar power to operate CO₂ heat pump water heaters, a combination of “renewable heat utilization through heat pumps” and “the use of carbon-free electricity” can be realized, thereby achieving decarbonization of hot water supply needs.
In recent years, with the significant increase in renewable energy generation facilities such as solar power, the issue of output control for renewable energy has become more prominent, especially during the transitional seasons of spring and autumn when electricity demand is relatively low. By shifting the heating time of CO₂ heat pump water heaters from nighttime to daytime and utilizing electricity generated from renewable sources, not only can this electricity be effectively utilized, but the need for output control can also be reduced. This application is known as “Demand Response (DR)” and is gaining widespread attention.
Additionally, by utilizing heat from the atmosphere as a renewable energy source, CO₂ heat pump water heaters contribute to increasing Japan’s energy self-sufficiency rate. We will continue to promote the further adoption of CO₂ heat pump water heaters as a key demand-side measure to achieve carbon neutrality by 2050.
