Geothermal data analysis from low enthalpy resource mapping

Abstract

With increasing interest in geothermal energy, also geothermal data analysis is
becoming an important issue. The portion of geothermal among all renewable energy
sources in Switzerland and its undiminished growth highlight the need for regional
resource evaluations. Rather 1-D models have interpreted the temperature data,
systematically collected since many years, however, only now the computing power
allows for joint interpretations, including for large-scale 3-D effects from geological,
topographical and hydrogeological features. By our study an integrated assessment
and evaluation of the geothermal potential is intended, accounting for individual
utilization scenarios and their specific requirements. The state-of-the-art compilation
is based on comprehensive 3D geological and thermal regional models of 20-40 km
extent. Thereby, zones of significant convective flow or preferential sites for borehole
heat exchanger systems (BHE) should be identified. In contrast to results obtained
from earlier geothermal resource assessments, now, existing geological,
hydrogeological information and petrophysical data are comprised within a full 3D
numerical evaluation. First results are now obtained from a well-documented
subsurface area in Northern Switzerland and from a Alpine topographies in central
Switzerland. Among various studies that have been performed on these sites, we
could demonstrate that geological mapping procedure provides accurate results when
compared to small-scale high-resolution 3D seismic profiles. The necessity for these
considerations is demonstrated by temperature data analyses.