Summary

Mongolia: Heating with solar power

atmosfair is financing and installing photovoltaic (PV) systems and electric heating technologies in Mongolia, helping institutions such as kindergartens and schools to move away from coal-based heating.

The project combines solar electricity generation with modern electric heating systems that can operate reliably even during Mongolia’s extremely cold winters. By reducing the use of coal, the project supports cleaner air, lower greenhouse gas emissions and healthier living conditions.

The systems are designed to generate approximately as much solar electricity over the course of a year as is needed for heating. During winter, some electricity is drawn from the grid, while surplus solar electricity can be exported to the grid during summer.

Electric heating

The first two solar-electric heating systems were commissioned in October 2023 at two neighbouring “twin” kindergartens in Ulaanbaatar. The buildings are almost identical, providing an opportunity to test two different approaches to electric heating under similar conditions.

Kindergarten A: Water-based heating with thermal storage

In Kindergarten A, we use a water-based heating system with heating rods to convert electricity from the 50 kWp photovoltaic system into heat. This heat is temporarily stored in heat storage tanks. This allows solar electricity to be used effectively for heating during winter, even without feeding electricity into the grid. The heat is distributed through insulated water pipes to radiators throughout the building.

Kindergarten B: Air-to-air heat pumps

Kindergarten B uses electricity from a 20 kWp photovoltaic system to directly and efficiently heat individual rooms with 19 air-conditioning units, also known as air-to-air heat pumps. As the name suggests, the heat pumps transfer heat from the outside air into the buildings. In a compressor cycle, a refrigerant evaporates in the outdoor unit at low pressure and absorbs heat from the surrounding air. This process works even at temperatures below zero. In the indoor unit, the refrigerant is compressed at high pressure and condenses, releasing heat into the interior spaces. If the system is operated in cooling mode, the process is reversed. Commercial refrigerators use the same principle.

A study in 2019 involving seven households showed that efficient heating with modern air-to-air heat pumps is possible even in Mongolia’s extremely cold climate¹. Even at very low temperatures, the systems remained more efficient than electric heating rods and produced an average of 2.8 kWh of heat for every 1 kWh of electricity consumed over the heating season. This is referred to as a Seasonal Coefficient of Performance (SCOP) of 2.8. In Germany, where winters are milder, SCOP values between 4 and 5 are common. Thanks to this higher efficiency, the photovoltaic system for Kindergarten B could be significantly smaller than the one used for Kindergarten A.

Mongolia and solar energy

Mongolia covers around 90% of its heating demand with domestic coal. In addition to its significant environmental and climate impacts, air pollution, which is largely caused by burning coal, is responsible for around 3,300 premature deaths each year in Ulaanbaatar alone². Switching to solar-electric heating can provide a cleaner and more sustainable alternative.

Winter in Mongolia is cold. With an average annual temperature of -2°C and winter temperatures that can fall to -40°C, Ulaanbaatar is the coldest capital city in the world. At the same time, photovoltaic systems in Mongolia produce around 1.8 times more electricity than systems of the same size in Germany (approximately 1,800 kWh/kWp/year compared with 1,000 kWh/kWp/year). This is due to the country’s strong solar radiation and the improved performance of solar panels in cold conditions.

When solar installations are mounted at a steep angle (45-50°) and oriented towards the south, they can generate as much electricity in winter as in summer in Mongolia’s high-altitude regions. By comparison, solar electricity production in Germany typically falls to around one-fifth of summer levels during winter. As a result, around 75% of the solar electricity generated in Mongolia can be used for heating, even without seasonal energy storage.

Prospects

The project demonstrates that solar-electric heating can be a practical alternative to coal-based heating, even in one of the coldest inhabited areas in the world.

atmosfair and its partners continue to assess the performance of both heating approaches and explore opportunities to expand solar-electric heating to additional schools, kindergartens, public institutions and households in Mongolia. Over time, further improvements in system design, operating costs and grid integration could support wider deployment of this technology.

Partner

kraftBoxx GmbH specialises in Power-to-Heat and latent heat storage technologies. The company supplies the water-based heating system, including the heating rods and latent heat storage units. Together with the Mongolian partner Solar Energy Consulting LLC, kraftBoxx supported the installation, commissioning and monitoring of the systems. Solar Energy Consulting LLC continues to support the operation, maintenance and monitoring of the systems.

The NewClimate Institute (NCI) is a non-profit organisation that develops and promotes practical climate solutions. NCI co-financed the air-to-air heat pump system installed at Kindergarten B.

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