Geothermal energy, solar energy, residual heat from industry ... these are all sustainable energy sources that complement one another. GeoWatt studies how thermal networks are able to match supply of heat with demand.

Using renewable energy more efficiently

Fourth-generation thermal networks enable us to use renewable energy more efficiently. In this field, GeoWatt focuses on entire thermal systems rather than separate buildings. “Geothermal energy is an excellent energy source for heating or cooling houses. Solar energy and residual heat from industry are also useful,” explains David Lagrou from VITO. “The more heat sources you can connect up, the more stable your heat network becomes.”

On a large scale

The deep drilling operations needed to obtain geothermal energy require significant investments. This is why GeoWatt thinks on a large scale: its researchers are examining the possibilities of thermal networks for use in business parks and large urban districts. “The Port of Antwerp is a great example,” says David. “We could heat the whole of Antwerp South using the heat generated by the petrochemicals industry. Geothermal drilling is not possible around the port, but it is in the north of the province. This means that you could potentially lay an extensive thermal network that connects different energy sources in an intelligent way.”

Lower temperatures

GeoWatt is also examining geothermal technology in more detail. The first-generation thermal networks often pump up water that is close to boiling, but a lower temperature is sufficient for many applications. “For technologies such as underfloor heating, 35°C may already be enough,” states David.

“In Herentals, we are looking at how we can pre-heat the water in a swimming pool to 25°C. To do that, it is sufficient to drill to 600 metres rather than 3 kilometres. If we can start to make good use of lower temperatures too, we will adjust the supply to the demand.”

Economic analysis

In the region around Genk, VITO successfully created an example of a fourth-generation network, where researchers are testing their developments. They are also examining the economic aspect. “In order to effectively estimate the costs and revenues of fourth-generation networks, we need accurate simulation tools,” explains David. “Thermal networks are expensive: some regions are better off investing in (practically) energy-neutral new-builds and home energy efficiency upgrades. We are also working together with local industry to develop fourteen pioneering demo systems. We hope to attract international industry partners with specific examples.”

GeoWatt forms the second work package in the project entitled ‘Towards sustainable energy supply in cities'. It forms part of Strategisch Actieplan Limburg in het Kwadraat (SALK), a programme of the Flemish Government intended to boost the economy and competitiveness of the Province of Limburg.