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The research project EPOS-eNLarge, a collaboration between Utrecht ľ�ϸ���Ӱ��, Delft ľ�ϸ���Ӱ�� of Technology (TU Delft), the Royal Netherlands Meteorological Institute (KNMI) and the TNO Geological Survey of the Netherlands, provides open access to their scientific labs and large-scale geophysical facilities, including an Earth Simulation Lab, a geothermal well and an earthquake data centre, to scientists undertaking research into the subsurface. Data of the Dutch subsurface is also accessible. By sharing research facilities and data openly, we aim to improve our collective knowledge on the subsurface, and pave the way to a safe and sustainable use of the subsurface.

Many of the current strategies to reduce greenhouse gas emissions rely on an increased use of the subsurface - that mass below our feet where groundwater, soil and rocks interact with human activities. The production of renewable energy from geothermal sources, the storage of carbon dioxide or energy surpluses in the subsurface, and the phasing out of gas and oil reserves are all important components of the energy transition and possible solutions to the climate crisis. But our understanding of the impact of these activities on the subsurface is still incomplete, which makes their widespread application more difficult.

The results of this collaboration can ultimately increase the efficiency and safety of geothermal and other subsurface projects.

The research project aims to provide a more complete understanding of the impact of natural and human uses of the subsurface. The project, a collaboration between Utrecht ľ�ϸ���Ӱ��, TU Delft, the Royal Netherlands Meteorological Institute (KNMI) and the TNO Geological Survey of the Netherlands, develops innovative large-scale research facilities, specialised laboratories and data centres across these locations, and provides free-of-charge access to labs and data to scientists undertaking research in the subsurface anywhere in the world.

“One of the main goals of the project is to apply the knowledge gained in the laboratory of how rocks behave at a small scale to predict what the rock behaviour will be at a much larger scale and under real-world conditions,” says Dr. Suzanne Hangx, Assistant Professor at the High Pressure and Temperature Laboratory at the Department of Earth Sciences, Utrecht ľ�ϸ���Ӱ��, and one of the scientists involved.

Bridging scales

For Hangx, the collaboration provides insights and results otherwise unattainable. “Each of us looks at a small part of the puzzle, but in order to be able to accurately predict the impact of subsurface usage by people, we need to work together across scales,” she says. “Tapping into each other’s strengths, we can get a physics-based understanding of what is happening in the subsurface at the scale of individual grains in our rocks, and extrapolate that to the kilometre-scale. Because this is the scale at which subsurface operations take place, and any possible effects are felt.”

Thanks to the laboratory research carried at Utrecht ľ�ϸ���Ӱ�� on centimetre-sized samples, the cluster has learnt a lot about some of the micro processes that control the behaviour of rocks. “At the , we can go a step further and explore what happens in the subsurface when we extract or inject fluid at unprecedented 1-400 metre scales,” says , research manager of the Rijswijk Centre.

Finally, at TU Delft and KNMI, large-scale monitoring facilities are used to test how the subsurface reacts to human activities. “While we can validate small-scale models through laboratory tests and controlled settings, validating models at the km scale relevant for subsurface geo-energy applications is very difficult and requires large-scale infrastructure,” says , Assistant Professor of Geothermal Engineering at TU Delft. “The data that we have on the subsurface together with the physical processes that take place are used to build models. With these, we can simulate how energy systems behave in large spatial and temporal scales. This alignment across scales helps us to better understand or even predict the impact of using the subsurface for geo-energy applications.”

“The results of this collaboration can ultimately increase the efficiency and safety of geothermal and other subsurface projects,” adds Ronald Pijnenburg, project manager of the research infrastructure.

Open access to research facilities and data

EPOS-eNLarge opens calls twice per year, welcoming proposals for free-of-charge access to any of the cluster’s facilities - the Multi-scale Imaging and Tomography (MINT) facilities at Utrecht ľ�ϸ���Ӱ�� (MINT-UU) and Delft ľ�ϸ���Ӱ�� of Technology (), the ESL Tectonic Modelling (Tec-)Lab, ESL High Pressure and Temperature (HPT) Lab, and Porous Media Lab at Utrecht ľ�ϸ���Ӱ��, the at Delft ľ�ϸ���Ӱ�� of Technology and the and of the TNO geological survey. The next call opens in February 2024.

Data generated at these facilities are made publicly available through the , therefore ensuring the efficiency and transparency of (inter)national earth scientific research.

About EPOS-eNLarge

EPOS-eNLarge is a new , funded by the Dutch Research Council (NWO). The project, a collaboration between Utrecht ľ�ϸ���Ӱ��, Delft ľ�ϸ���Ӱ�� of Technology, the Royal Netherlands Meteorological Institute (KNMI) and the TNO Geological Survey of the Netherlands, provides the missing link needed to apply our understanding of micro-processes in the subsurface at the kilometre-scale. It builds on the research project , a Dutch national research infrastructure for research into geo-resources.