Great Expectations for Geothermal Energy to 2100

Abstract

Geothermal energy systems: have a modest environmental footprint; will not be impacted by climate change; and have potential to become the world’s lowest cost source of sustainable renewable thermal fuel for zero-emission, base-load direct use and power generation. Displacement of more emissive fossil energy supplies with geothermal energy can also be expected to play a key role in advancing both energy security and climate change mitigation strategies.In this context, shared challenges on the road to a global portfolio of safe, secure, competitively priced energy supplies are drivers for international cooperation in research, exploration, pilot demonstration and pre-competitive development of geothermal energy resources and technologies.
The intellectual and financial inputs for international, pre-competitive initiatives are coming from public and private investors with aspirations for low emissions, affordable, and globally deployable 24/7 energy supplies. It is reasonable to conclude that the outcomes (improved technologies and methods) of these collective efforts over the next 20 years will underpin great expectations for widespread, profitable and environmentally sustainable use of geothermal energy for centuries to come. This paper provides a synopsis of recent findings including estimates of theoretical, technical, economic, developable geothermal energy resources and existing supplies for both power generation and direct use, and the objectives of notable international fora enabling cooperation to reduce impediments to widespread use of geothermal energy. Key conclusions are:
•Engineered Geothermal Systems are expected to fuel roughly half of an expected supply of 4.6 EJ per year (~160 GWe) of geothermal power generation by 2050, and potentially up to 32.4 EJ per year by 2100.
•Geothermal energy can conservatively be expected to meet:
-more than 3% of the total global demand for electricity by 2050 and potentially more than 10% by 2100; and
-about 5% of the global demand for heating and cooling by 2050 and potentially, more than 10% by 2100

•The technical potential of geothermal energy is enormous (118 EJ/yr to 3km and 1,109 EJ/yr to 10km for electricity and 10 to 312 EJ/yr for direct use in context of 315 EJ/yr average heat flux at 65 mW/m2). Resources size is clearly not a limiting factor for global geothermal energy development; and
•With its natural thermal storage capacity, geothermal is especially suitable for supplying both base-load electric power generation and for fully dispatchable heating and cooling applications in buildings.