Aquifer thermal energy storage following up on the tu delft geothermal well

Abstract

In 2020 TU Delft will build a geothermal well producing enough energy to power all its faculties and a number of buildings surrounding the campus. This is done to meet the climate goals the TU set itself: an energy neutral campus by 2040. Geothermal plants are designed to produce for 30 years. After this period, by 2050, the TU has to be energy-neutral without the geothermal heat flowing from deep underground. To prevent falling back to fossil fuels there is need for a new energy source. In this feasibility study one of the options is investigated, low temperature aquifer thermal energy storage (LT-ATES). This technology stores heat-energy produced during summertime in aquifers, during wintertime this water is used to heat the faculties. It was found that a LT-ATES system is viable. A 19 MW ATES system containing 23 cold and 23 warm wells to a depth of 180 meters is needed. Cooling during summertime is not sufficient to charge the system to meet the winter heating demand; therefore an additional solar thermal collector field of 35.000 m2 is needed. Designing a strategy for 2050 means that there is a considerable amount of assumptions to be made. To optimize the LT-ATES-system, a more in-depth study should be performed.