ECO-GHP · Multi-criteria assessment and optimization of geothermal heat pump systems

The use of shallow geothermal energy is continuously rising and, in particular, the application of vertical ground source heat pump (GHP) systems is expanding. Such applications are attractive for their potential to reduce greenhouse gas emissions while offering economic advantages in comparison to fossil-fuel based space-heating. Single GHP systems are well established for small residencies. Growing interest is directed towards bigger scale applications with galleries of multiple GHPs, for which much less experience exists and little research on appropriate planning and design is available. During the proposed reintegration phase at the Engineering Geology Institute at the ETH Zurich, a three-year project is planned that develops an innovative computer-based assessment/optimization methodology. It benefits from the previous Marie Curie Intra-European Fellowship by setting up a state-of-the-art full environmental assessment procedure according to Life Cycle Assessment (LCA) standards. Further, it contrasts the LCA-based evaluation of GHP systems with respect to different impact categories with technico-economic criteria. The different criteria will be quantified in a flexible manner for a broad range of multiple GHP configurations. By implementation of the assessment procedures into a mathematical optimization problem, optimal GHP gallery design and operation will be computed. The methodology will allow categorising sensitive status, design and control parameters with respect to various, potentially contradicting criteria. In the final phase, demonstration to two prominent real cases is planned in order to show applicability and to examine the potential of the new approach to improve current multiple GHP system planning practice.