A critical review of the techno-economic feasibility and sustainability of enhanced geothermal systems (EGS): Global insights and strategic pathways

Geothermal energy is abundant beneath our feet but utilizing it economically and sustainably remains a challenge. While EGS offers a promising way to access deep geothermal energy, this study examines its techno-economic feasibility and long-term sustainability. The current levelized cost of electricity (LCOE) for global EGS projects ranges from $35 to $250 per MWh, depending on site conditions and the technology used. In the U.S., the median LCOE for current EGS projects is typically above $70 per MWh and higher than the national average for all combined electricity sources. Meeting the U.S. DOE's 2035 target of $45/MWh often requires production rates exceeding 100 kg/s. In EGS, production directly depends on the injection rate. The continuous operation at high injection rates increases the risk of short-circuiting and channeling, resulting in premature thermal breakthrough. Thus, the rock's capacity to reheat fluid becomes impaired. The literature reports thermal drawdown rates of 1–4 % annually when flow rates are 30–70 kg/s. Production at higher rates might allow only 10–15 years of operation before the temperature drops below the 150 °C threshold needed for economic power generation. The lack of long-term field data adds uncertainty and limits reliable forecasting. Real-time temperature monitoring can help optimize operational strategies. Long-term EGS success depends on aligning production targets with site-specific conditions through adaptive management.