Potential for High Temperature-Aquifer Thermal Energy Storage (HT-ATES) in the dutch subsurface

Abstract

High-temperature aquifer thermal energy storage (HT-ATES) involves seasonal storage of residual heat and is an important instrument in building an energy efficient future. HT-ATES could prove to be a better alternative than the lower enthalpy aquifer thermal energy storage (ATES), because it can be directly applied to a district heating network without using heat pumps. There is however a knowledge gap of the potential of HT-ATES in the Netherlands. This study aims to give a first-order approximation of the spatial distribution of this potential in specific aquifers, using a Java workflow. Using recently developed subsurface models of the Netherlands, it was possible to make probability maps of the economic potential of HT-ATES. A previous study by Pluymaekers et al. (2013) indicated certain shallow reservoirs within the North Sea super group to be of interest for HT-ATES. This study therefore assesses the potential in these aquifers, together with certain deeper aquifers. By assuming a log-normal distribution and by generating a transmissivity distribution through Monte Carlo sampling, transmissivity maps with P10, P30, P50, P70 and P90 confidence levels are generated. To identify key parameters that influence the recovery efficiency and to find a computationally fast method for the approximation of these efficiencies, two faster analytical methods are compared with the numerical model DoubletCalc3D. The results indicated that the Rayleigh-based method (Schout et al., 2014) is the most accurate and computationally fast method, whereas the Radial Dupuit Interface Flow method (Bakker, 2009) delivered inadequate results. The Rayleigh-based method is then implemented into the Java workflow to calculate the Coefficient of Performance (COP) of the HT-ATES system. The Excel workflow that was developed by Pluymaekers et al. (2013) is used to calculate the Levelised Cost of Energy (LCOE), where a LCOE <6 EUR/GJ marks an economic potential for HT-ATES, and higher values have less potential. The results indicated that the deeper aquifers (Delft Sandstone member, Rijnland group and Lower/Middle North Sea groups) have no potential, with some local exceptions, due to the low transmissivities and depth of the aquifers. The shallower reservoirs (Breda, Oosterhout and Maassluis formations) showed a high potential for HT-ATES, confirming the assessment done by Pluymeakers et al. (2013).