Decarbonising heat in Denmark
3 July 2023

Welcome to Ringsted. Even though its population is just over 23,000, the city is one of Denmark’s busiest transit hubs, serving as an important link between Jutland and Copenhagen.

It’s up to Ringsted District Heating Utility (DHU) to supply a safe, reliable source of heat for residents and businesses within its 124-km district heating network. The utility heats more than 7,000 homes, schools, stores, sporting facilities and other buildings in the area.

Given the importance of decarbonising Europe’s energy sources, several years ago, Ringsted DHU pledged to the municipality that it would achieve 95% carbon-free heat by 2020 – without significantly increasing customers’ bills. However, this was easier said than done: Ringsted DHU’s heat plant was powered by fossil fuels. The utility would need all the help it could get.

Enter Danfoss Climate Solutions. The technology supplier partnered with Honeywell, Geoclima and Unicool to design a 21st-century, energy-efficient heat plant that, among other sustainability features, could improve efficiency and reduce costs by recovering and recycling waste heat. All of these subsequent investments came from the utility’s reserves, keeping the cost of heat stable for the people of Ringsted.

During six months of renovations, Danfoss paired its award-winning Turbocor water-water heat pumps with Honeywell’s ultra-low global warming potential (GWP), energy-efficient Solstice® ze (R-1234ze) refrigerant. In fact, it was the only refrigerant with a low enough GWP to comply with Danish regulations.

In addition to efficiency and compliance, safety was an important consideration. According to Julien Soulet, VPGM, Fluorine Products, EMEA, Honeywell Advanced Materials:

‘Heat pumps using low-GWP, energy-efficient HFO [hydrofluoroolefin] refrigerants like Honeywell Solstice ze are ideal for district heating schemes in densely populated urban areas like Ringsted because they are safer, operate reliably and can provide everyone with access to heating that is affordable and sustainable.’

The results speak for themselves: Ringsted DHU met its energy, cost reduction and emissions reduction goals after just one year in operation. The solutions implemented by Danfoss, Honeywell and their partners increased the heat plant’s capacity and efficiency by approximately 30% and 20%, respectively. Furthermore, the once unimaginable goal of 95% carbon-free heat was exceeded – instead, Ringsted DHU produced 97% carbon-free heat.

Honeywell knows how important addressing climate change is, and the company is proud to offer solutions that can make an immediate, positive difference in the heating and cooling sectors. To date, use of Honeywell Solstice technology has helped avoid the potential release of the equivalent of more than 326 million metric tons of carbon dioxide into the atmosphere, equal to the carbon emissions from nearly 70 million gasoline-powered passenger vehicles per year. (Calculations are based on actual sales of Solstice products in pounds from January 2010 through December 2022 and converted with the US Environmental Protection Agency Greenhouse Gas Equivalencies calculator.) The Solstice ze (R-1234ze) refrigerant used in Ringsted is helping more and more municipalities and utilities deploy safer, more energy efficient and lower cost heat pumps, meaning more and more towns and cities are reducing their carbon footprint.

Change can be difficult, especially when it comes to the complexities of updating legacy energy sources. However, choosing the right technology at the right time is key to balancing energy consumption, climate change and economic impact now and for decades to come.

Read more:

Decarbonised energy
The Green Way
Story contributor
Key numbers
tons of carbon dioxide potentially kept out of the atmosphere