A new Danfoss report identifies waste heat from data centers, industrial facilities, supermarkets and wastewater treatment plants as a major unused energy source. According to the report, at least 3,100 TWh of waste heat went uncaptured globally in 2023, with recovery potentially providing annual savings of up to EUR 140 billion.
Danfoss outlines three pathways for recovering and reusing waste heat: on-site reuse, microgrids and industrial clusters, and district heating integration. Heat pumps can be used to raise lower-temperature waste heat to temperatures suitable for space heating, hot water, industrial processes or district heating networks.
The report highlights data centers as a potential source because they operate continuously and convert nearly every unit of consumed energy into heat. Recovered heat can supply nearby facilities through microgrids or be integrated into district heating systems. Danfoss says facilities generating continuous, high-temperature waste heat, including manufacturing plants and data centers, often have the shortest payback periods.
In Germany, Danfoss analyzed 178 district heating networks serving more than 5,000 households and industrial waste heat sources located within 1 km (0.62 miles) of those networks. The analysis found that qualifying industrial waste heat could cover approximately 30.4% of the networks’ combined annual heat demand. The underlying register excludes combined heat and power plants already supplying district heating and does not yet include data centers.
An aluminum manufacturing facility in Denmark illustrates on-site recovery. A heat pump raises recovered process heat from 16°C (61°F) to 60°C (140°F) for facility heating, while a second booster heat pump raises part of it to 90°C (194°F) for production pre-heating. The project is projected to eliminate 205,600 m3 (about 7.26 million ft3) of gas use annually and reduce CO2 emissions by 407 tons per year.
“The technology is here. The opportunity is here. Now we need the energy system to catch up. Industry must make heat recovery standard practice, energy operators must make connections easier, and governments must remove the barriers that make electricity more expensive than gas for these investments. Get those pieces in place and waste heat stops being waste. It becomes a source of cheaper energy, greater resilience and stronger competitiveness,” said Kristian Strand, President, Danfoss Climate Solutions.
