From November 22nd to 24th, the Austrian Geothermal Association (GTOE), in collaboration with the Geothermal Alliance Bavaria (GAB), hosted the Geothermal Symposium 2023, focusing on “Geothermal Energy – Thinking Without Boundaries.” The event took place at the Geinberg Thermal Spa in Upper Austria.

Nikolaus Petschacher, representing Hydro GmbH, delivered a presentation on the opportunities and limitations of thermal groundwater utilization in Graz.

Abstract:

Opportunities and Limitations of Thermal Groundwater Utilization in Graz

N. Petschacher & V. Vasvári

Despite the favorable hydraulic characteristics of the shallow aquifer in the Graz area, implementing large-scale projects for thermal groundwater utilization proves to be highly challenging. This is mainly due to the high number of external wells, which must not be hydraulically or thermally disadvantaged. While hydraulic impacts are typically localized, thermal effects can extend extensively depending on extraction rates and hydraulic aquifer properties.

This study investigates the potential for minimizing thermal impacts based on a hydraulically-thermally coupled groundwater model, considering heating and cooling load conditions, and optimizing the placement of wells and infiltration structures. Additionally, deficiencies in common thermal calculations or simulations regarding the prevailing publicly available data are discussed. The paper concludes with a discussion on the opportunities and constraints of thermal groundwater utilization in Graz.