Monitoring of the Aquifer Thermal Energy Storage system at Koppert-Cress

The project

Koppert-Cress is a horticulture company and has a relatively large heating demand. An Aquifer Thermal Energy Storage (ATES) system was built to heat and cool their greenhouses sustainably and was transformed into a High-Temperature ATES system to store temperatures more than 25 °C. To be able to do this the HT-ATES system of Koppert-Cress has a temporary pilot permit and is used in multiple projects to research the storage of relatively high temperatures (up to 40 °C) in shallow aquifers.

The drilling installation of Nathan. For both types of drilling activity (monitoring well or DTS), a different drilling technique was used.

How to measure heat stored in the subsurface and its impact?

The aim of the research going on at this pilot is to get insight into the distribution of heat that is stored in the subsurface and to analyse the water quality changes due to the temperature changes. To do so, a monitoring well was drilled near one of the warm wells of the ATES system, from this well we can take water samples from the aquifer to measure the water quality changes in the lab. Next to this we also installed 2 Distributed Temperature Sensor (DTS) cables that measure the temperature distribution along with the full depth of the aquifers used for heat storage, up to 170m depth. This can subsequently be used to determine the distribution of the stored heat.

This work is carried out within the TKI project where we work to optimise the system of Koppert-Cress and Heatstore, which funded a significant part of the additional monitoring that was installed.

Optical fibres (fibreglass) are used to measure the temperature in the subsurface. Here the cable is prepared by an engineer from Inventec.

Craftmanship

It was exciting to be there on the project site and to contribute to different activities, especially because this was the first time I witnessed these kinds of drilling activities. It taught me that working with the subsurface requires craftsmanship and we have to be careful to maintain a good quality of available aquifers & groundwater. In cooperation with the different parties, we realised what we planned during the past six months. Now it’s time to wait and acquire the data we are interested in, to be continued!

All new DTS locations are drilled, all cables are connected and led to the measuring unit (not on picture).