Commercial geothermal technologies currently can only utilize geographically rare dry steam resources or only slightly more common hydrothermal (i.e., aquifer) resources. This geographic dependence limits the impact geothermal energy can play outside of select regions. Yet innovation in enhanced geothermal systems (EGS) may unlock geothermal power production in regions that contain much more common hot dry rock resources (i.e., where there is hot rock but insufficient or little natural permeability or fluid saturation). EGS work by injecting fluid underground to open preexisting fractures, thereby increasing permeability. By drilling a production well into this man-made reservoir, a heat transfer fluid can be circulated in order to produce power at the surface. However, both conventional and enhanced geothermal are constrained by high upfront costs around drilling and identifying applicable project locations.
