Review: NEFI Technology Talk: Decarbonisation of heating and cooling supply with geothermal energy and industrial waste heat

by Oxana Schmidt

The energy transition is also a heat transition, and this aspect has hardly been talked about so far. Since the beginning of the year, the energy crisis has brought this challenge into the public sphere. At the NEFI Talk "Decarbonisation of heating and cooling supply with geothermal energy and industrial waste heat" on 14.10.2022 in Linz, five keynotes highlighted the possibilities of how heating and cooling networks can be decarbonised with the help of geothermal energy and industrial waste heat.

Edith Haslinger, geothermal energy expert and senior scientist at the AIT Center for Energy, gave the more than 60 participants an insight into the use of geothermal energy.
In Austria we consume 316 TWh of energy per year, 50 percent of which is used for heat. Heat is used 62 percent for space heating, 18 percent for process heat above 200 degrees and 21 percent for process heat below 200 degrees. Heat in Austria is currently produced with oil, natural gas, wood and district heating. Renewable energies are therefore needed to decarbonise heat production. This is where geothermal energy comes into play. In a broad sense, geothermal energy is the thermal energy stored in or produced by our planet. In a narrower sense, geothermal energy refers to the thermal energy stored in the accessible part of the earth's crust and its application-related extraction.
In the heat transition, geothermal energy is to establish itself as a renewable and base-load capable form of energy. In 2020, there were already 90,00 active installations in Austria with 1,100 megawatts of capacity. Edith Haslinger showed that there are already many implementation examples in Austria where geothermal energy has been integrated in new buildings, but also in existing buildings. The hurdles for implementation lie more in building and tenancy law. However, before geothermal energy and heat pumps are used, the potential for energy efficiency of buildings and industrial processes must be evaluated. After all, swapping the energy source does not go far enough.
Geothermal energy may be an invisible technology in operation, but it cannot be overlooked in the construction phase and drilling. In his keynote speech, Oliver Tausch, RED Drilling & Services GmbH, gave an impressive demonstration of how the project process for deep drilling rigs can proceed from project generation to drilling.
Geothermal energy as a renewable and base-load capable form of energy in industrial processes is not yet an established application. In the three concluding keynotes by Thomas Kienberger, Stefan Reuter and Johannes Riedl, the great potential of waste heat utilisation in industry for energy efficiency and reduction of CO₂ emissions became clear.

Thomas Kienberger, Head of Chair of Energy Network Technology & NEFI_Lab, Montanuniversität Leoben, presented the keynote by Andreas Hammer, Chair of Energy Verbund Technology, University of Leoben, on the survey of industrial waste heat potentials in Styria. Conclusion: Currently there is 6.88 TWh of unused heat that could be used for various industrial processes.
Stefan Reuter, Junior Research Engineer at the AIT Center for Energy, presented a techno-economic evaluation of the integration of waste heat in his keynote speech.
Johannes Riedl, Junior Research Engineer at the AIT Center for Energy, presented in his keynote the use of high-temperature heat pumps as a key technology for future energy systems. In industry, the use of heat pumps is in the early phase of market diffusion. Unused waste heat can be re-integrated into the process by using high-temperature heat pumps to raise the temperature to up to 160°C. In current research projects, the use of
4 demonstration plants are being tested in resource- and energy-intensive industries (steel, petrochemicals, minerals, paper).


Presentations (PDF-Files in German)

Keynote 'Geothermal energy as a central building block of the heat transition', Edith Haslinger, Center for Energy, AIT

Drilling planning and drilling technology in deep geothermal energy
Oliver Tausch, RED Drilling & Services GmbH

Industrial waste heat potentials - possibilities of determination and case study
Andreas Hammer, Montanuniversität Leoben

Techno-economic evaluation of waste heat integration
Stefan Reuter, Center for Energy, AIT

High-temperature heat pumps
Johannes Riedl, Center for Energy, AIT