Heat Storage in Hot Aquifers: The feasibility of High Temperature Aquifer Thermal Energy Storage in Denmark, the Gassum Formation in the Stenlille Structure.

In this PhD Thesis we will develop new technology to improve planning of energy storage in geothermal reservoirs through high-quality modeling. By using geothermal reservoirs with high temperature, energy may be stored in these geological layers with minimal heat loss.
The focus will be on Danish geothermal reservoirs (Gassum Formation in the Stenlille Structure), because heat storage is likely to be the missing link in planning sustainable energy production in Denmark, where several sources of energy should interplay.
By storing energy at low heat loss in hot aquifers we obtain an effective interplay between different sources of energy, so that the degree of coverage with sustainable energy can increase at an acceptable cost.
Heat storage in the Danish underground should thus be of increasing interest for optimizing the use of energy resources. A potential sandstone reservoir in Denmark (Gassum Formation in the Stenlille structure) is studied to allow us to discuss which geological and technical characteristics an aquifer for a Heat Storage plant in Denmark should have.
We develop 2D (the Simple Model) and 3D (The Stenlille Model) models for an High Temperature Aquifer Thermal Energy Storage system using analysis of geological and geophysical data (core data, well logs and seismic lines), heat transfer and finite elements to calculate Recovery Efficiency (72%), Heat Storage Capacity (1.8 1018 J) and Thermal breakthrough time (66-77 years) in Gassum Formation at Stenlille.
Both models developed are feasible and lead to similar results but Gassum Formation is modelled differently. In the Simple Model a simplified geological model of Stenlille structure is used, in the Stenlille Model the Gassum Formation is modelled in three scenarios according to real data and combination of different data sources (well logs, seismic lines and core data) with the use of Geostatistics.
The PhD Thesis is part of The HeHo (Heat Storage in Hot Aquifers) project developed in collaboration with GEUS (Geological Survey of Denmark and Greenland) Dansk Fjernvarmes Geotermiselskab and Niels Bohr Institute (Copenhagen University- Denmark), with participation of Niek Molenaar, Panterra srl (Leiden- Netherlands) and KAIST. HeHo is sponsored by the Danish Council for Strategic Research grant 10-093934.