The Influence of Regional Groundwater Flow and a Neighbouring River on the Behaviour of an Aquifer Thermal Energy Storage System

Abstract

One promising solution for mitigating CO2 emissions in arid regions is to use Aquifer Thermal Energy Storage (ATES) systems in cooling and heating systems. However, ATES systems need to be subjected to geohydrological investigations before their installation to ensure high performance. Two geohydrological properties are considered: regional groundwater flow and the influence of neighbouring rivers. This study considers a hypothetical ATES system within the city of Hilla, Iraq. MODFLOW 6.1 software was used to simulate the influence of the two properties. The simulation tested two locations situated at 75 m and 300 m from the river. Each location was explored using three flow rates: 10 m3/d, 50 m3/d, and 100 m3/d. The results indicate that the temperature change in the warm and cold wells increases proportionally with time of operation and rate of flow. For example, the temperature of the middle layer (for 10 m3/d operation) changes from 29 °C (after one year) to 34 °C (after twenty years operation), while it changes from 34 °C (one year) to 35 °C (twenty years) under 100 m3/d operation. Another result is that the available regional groundwater flow has a negligible influence on the storage system, while the neighbouring river has a high influence on the stored energy when the distance between them is 75 m or less. The paper recommends the installation of ATES systems at least 300 m from the bank of a river.