Heating and hot water account for nearly 80% of the total energy consumption of a building. As our towns and cities continue to expand, the limited space in urban centres and growing demand for cooling systems add to the challenge of reducing the carbon footprint of the building sector. Low-temperature heating networks that use water as their energy carrier are an effective heating, cooling and heat recovery solution, but laying the pipes used by these networks involves major installation work that comes with a high price tag.
In replacing the water with CO2 circulating in narrow, flexible pipes, ExerGo has developed a uniquely compact and effective technology for low-temperature DHCNs. The initial investment required is up to 25% lower and network performance is better than for water-based networks. In addition, using CO2 as the heat carrier makes an 80% saving in primary energy compared to systems that use fossil fuels. “Its flexibility and speed of installation mean that this system can be installed in many projects that were previously considered too costly or not possible due to lack of space,” says Alberto Mian, ExerGo’s CEO. “In major networks, our compact solution can also be used for the last kilometre, reaching right in to the otherwise inaccessible historical centre of a town or city.”
This start-up, a spin-off of EPFL, the Federal Institute of Technology in Lausanne, is targeting the worldwide market. Its modular technology with a capacity of up to 4 MW will work in different climates and with a wide range of locally available renewable energy sources, making it adaptable to the energy situation specific to each country. The system uses heat at between 5 and 15°C extracted from a lake, river or geothermal source but it can also recover residual heat at temperatures of up to 40°C. This energy can be distributed to buildings for cooling or used to power heat pumps to provide reliable heating and hot water.
ExerGo supplies the pipe infrastructure system and the heating and cooling exchangers used in the buildings. “Our solution is for public utilities companies, property owners and developers, and businesses who want to make use of their residual heat,” says Alberto Mian. The technology has been proven to work in a 450-kW thermal network demonstrator that supplies three buildings on the Energypolis campus in Sion. Several feasibility studies are also under way in Switzerland and Europe. ExerGo raised 5.2 million euros of capital in 2023, which should enable the company to get even further ahead with this technology and step up commercial production of its system, the only one of its kind in the world.
ExerGo SA