Fig. 9
From: Hydrological constraints on the potential of enhanced geothermal systems in the ductile crust
Average thermal energy output and injection pressure for different NDR-EGS operational scenarios with vertical (circles, triangles) or horizontal (stars) production/injection intervals, injection rate (Qinj) of 40 (triangles) or 80 (circles, stars) kg s−1, and maximum permeability (kmax) of 10–16 (blue), 10–15 (black), and 10–14 (red) m2 in the stimulated volume. Error bars show two standard deviations averaged over the first 20 years of operational lifetime. Grey bars show the brittle failure criterion, ductile failure criterion, and lithostatic pressure range at the depth of the modeled NDR-EGS system. Injection pressures in excess of the ductile failure criterion or lithostatic pressure indicate inadequate permeability increase in the stimulated volume