Waste heat is transported to the customer by truck

20.04.2026

Source: E & M powernews

A research project aims to bring customers in rural regions together with waste heat suppliers from industry. A heat storage unit on wheels should make it possible.

In rural areas in particular, waste heat sources from industry and potential customers are too far apart for a heating network to be worthwhile. This is where the "WärmeEngel" research project comes in, which is being implemented by the Cologne Institute for Renewable Energy (CIRE) at Cologne University of Applied Sciences together with the Oberberg district and the Bergischer Abfallwirtschaftsverband (BAV).

"With our project, we want to demonstrate a locally adapted solution for how climate-neutral heat can be flexibly delivered to customers without permanently installed grids," said Professor Thorsten Schneiders from CIRE. The aim of the project is to transport waste heat from landfill gas cogeneration plants at the Leppe waste disposal center east of Cologne to a vocational college around 16 kilometers away using new mobile latent heat storage units, i.e. a storage system on a truck.

The energy is to be fed into the existing heating system at the Dieringhausen vocational college, a property of the Oberberg district with an annual heating requirement of 910,000 kWh. According to TH Köln, the charging and discharging process will each take around eight hours.

The salt sodium acetate trihydrate serves as the storage medium

The mobile latent heat storage units are based on the phase change material sodium acetate trihydrate. This salt absorbs heat when it changes its aggregate state from solid to liquid. The phase transition takes place at a temperature of 58 degrees Celsius, which means that around 2.5 MWh of waste heat can be "absorbed and transported almost loss-free" per storage unit, writes the TH Köln.

The Bergische Abfallwirtschaftsverband provides the waste heat and is responsible for the logistics. TH Köln is responsible for the measurement technology and the overall energy assessment. To this end, the researchers want to develop a digital twin of the system and a publicly accessible dashboard that displays parameters such as heat quantity, power output and emissions balance in real time.

The Wärmeengel project is being carried out as part of the "REGIONALE 2025 Bergisches RheinLand" and is being funded by the Ministry of Economic Affairs of the state of North Rhine-Westphalia and the EU with 1.5 million euros.

Author: Heidi Roider