Soil monitoring improves insight into aquifer thermal energy systems

Published: 11 September 2014

In Utrecht, research institutes, business, and the city and provincial authority of Utrecht are teaming up in a way that is unique in the world to improve the performance of aquifer thermal energy systems. In a number of areas, a three-dimensional glass-fibre network is being installed underground to measure temperatures in the subsurface over the course of the seasons. This will make it possible for the first time to see how, in these systems, the energy balance in the soil develops over time and how the soil energy potential in each area can be used optimally.

To make subsurface soil monitoring possible at the Rijnsweerd Office Park and the Utrecht Science Park, in the Utrecht Central Station area, in Eindhoven Strijp S and in Delft, the Utrecht Sustainability Institute established the FOME-BES research project (Fibre Optic Monitoring of the underground Energy Balance of Soil Energy Systems). This project will bring together the expertise of Deltares researchers in Utrecht and Utrecht University, linking it to sustainable challenges in the Utrecht region. The city of Utrecht hopes to become an energy-neutral city by 2030, and high-performance aquifer thermal energy systems could make a major contribution.

However, there are gaps in our scientific knowledge about how the stores of heat and cold develop over the course of time. The simulation models currently available do not provide an adequate picture of the extent to which hot and cold sources affect each other and the required distance between them. Subsurface soil monitoring using glass fibre can provide this information: it generates, literally, a 3D picture on the surface of how the energy balance is developing below the ground. This breakthrough technology will help to make full use of the soil energy potential in a sustainable way.
The subsurface structure in the Netherlands can vary considerably. That is why the project compares aquifer thermal energy systems in Utrecht with similar systems in Delft and Eindhoven. The results of the project will be available in early 2017; the initial results are expected in early 2015.

The project is being conducted by a consortium consisting of Deltares, Utrecht University, Utrecht Sustainability Institute, Royal HaskoningDHV, Priva, BAM Technical, CMS, a.s.r., Park Strijp Energy and the city of Utrecht. The studies at the test locations will be financed in part by a.s.r. and the provincial authority of Utrecht (which have joined forces in the Kantorenpark Rijnsweerd Foundation) and Utrecht University. The venture as a whole is receiving support in the form of a subsidy from the ‘Energy savings in the built environment’ Knowledge and Innovation Top Consortium.

More information about the project is available on, where you can also subscribe to the project newsletter.