Feasibility of geothermal energy extraction from medium depth Danish limestone aquifers

Energy storage systems are designed for storing waste heat and excessive energy production (generated by solar panels, windmills, biomass plants and industrial processes) in e.g. the warm season to recover it during cold periods.

This PhD project will evaluate the potential for extracting and storing thermal energy from/in medium depth limestone reservoirs in Zealand, Denmark.


 Thermal energy storage technologies, in particular Aquifer Thermal Energy Storage (ATES) and Borehole Thermal Energy Storage (BTES) are key points to overcome the limited efficiency of “green energy sources” such as waste incineration, wind and solar energy, and help in the transition to a fossil-free society.

ATES is the most popular storage technology due to the low cost of investment and the possibility to overcome the discrepancy between energy production and demand when both the energy source (e.g. solar energy) and the demand are highly variable. In ATES systems, underground layers (e.g. a sand, gravel or limestone layer) are used for the seasonal or daily storage of heat.

The transfer of thermal energy is achieved by extracting and re-injecting groundwater at a modified temperature level.


The aim of this PhD project is to evaluate how the porosity, permeability and elasticity (i.e. texture, degree of cementation and fracturing) are distributed in the limestones of Zealand and how the limestones respond to the cyclic thermal stress due to the extraction of geothermal energy and thermal heat storage.


The project aims to demonstrate the successful employment of geothermal energy and thermal energy storage in the subsurface of Zealand with a focus on limestone formations and to identify the best locations where such technologies could be applied.


Irene Rocchi
Associate Professor
DTU Sustain
+45 45 25 19 16


Ida Lykke Fabricius
Professor Emerita
DTU Sustain
+45 45 25 21 62