PUSH-IT

The EU aims to have a net-zero greenhouse gas (GHG) economy by 2050, with 55% reduction on 1990 levels by 2030. At present, heating and cooling represent around 50% of the final energy demand in Europe and are mainly supplied by fossil fuel derived energy. It is therefore essential for heating and cooling to decarbonise to achieve EU ambitions.

A challenge for decarbonizing heat systems is the size of the seasonal mismatch between demand for heat and heat generation from sustainable sources. One of the main solutions to address this mismatch is to store energy for later use if it is not needed at time of conversion. Optimal utilisation of sustainable heat requires storing large amounts of heat to account for seasonal supply and demand fluctuations. Various technologies have been proposed for large-scale heat storage in geothermal reservoirs  and  low  temperature  storage  is  routinely  applied.

The PUSH-IT project (Piloting Underground Seasonal Heat Storage in Geothermal Reservoirs) focuses  on  extending  storage temperature ranges  to high  temperatures by showcasing three high-temperature heat storage technologies that are fit for a wide variety of geological conditions covering most locations in Europe: Aquifer, Borehole and Mine Thermal Energy Storage (ATES, BTES and MTES). Each of the three technologies will be showcased in two different sites, corresponding to a 'demo' site, ATES in Delft, BTES in Darmstadt and MTES in Bochum, and a 'follower' site in  Berlin, Litomerice and Cornwall, respectively.  

The heat storage to be demonstrated at the TU Delft is a high-temperature aquifer thermal heat storage (HT-ATES) system in combination with geothermal wells as a source for heat. ATES systems use two or more wells for the injection or extraction of water to carry heat to or from reservoirs or aquifers. The HT-ATES in Delft will store about 60 TJ of surplus heat in the summer, used to supply peaks in winter. The  temperature  level  provided  by  the  geothermal  heat  source  is  78  °C.  The ATES system pre-design constitutes seven wells storing heat in an aquifer at 150 to 250 meter depth.

PUSH-IT is an international and interdisciplinary project. It aims to address and include all relevant societal, technological and geologic conditions  at our  demonstration  sites by  adopting  and applying  an  inter-and  transdisciplinary  approach  to technology development,  innovation  and  application  in  society.  Amongst  the  partners  are  heat  network  operators,  drilling companies,  system  component developers  and  academic  institutions  with  expertise  across  multiple  disciplines.

Project Results 

The main objective  of  PUSH-IT  is  to showcase  the  full-scale  applications  of  heat  storage  (up-to  90°C) of  three different  technologies in  geothermal  reservoirs  at six different  sites  with  various  societal,  heat  network  and geologic conditions relevant across Europe. PUSH-IT will implement, develop and test the ability of Mine, Borehole and Aquifer Thermal Energy Storage technologies (MTES, BTES and ATES) to store and recover heat.

Other project objectives and ambitions are:

• Enable joint decision making of citizens, regulators and operators to increase social acceptance;
• Development  of  enabling  technologies  to  adapt  thermal  energy  storage  in mines  (MTES),  in  boreholes (BTES)  and  in  aquifers  (ATES)  to  a  wide  range  of  geological  conditions;
• Develop  an  open-source  tool  to  assess  and  optimise  levelised cost of energy (LCOE)  reduction and costs  of carbon  emission reduction;
• Optimised  integration in  heat  systems  via  co-simulation  and  machine  learning.

In summary, the anticipated results are:

• Demonstration of seasonal heat storage;
• Engaging society and organisation;
• Reducing CO2 emissions and costs;
• Fast track market upscaling.

The project will run from 2023-2027. For questions, please contact the Project leader Dr. Martin Bloemendal j.m.bloemendal@tudelft.nl.

This project is funded European Commission under grant Agreement 101096566