Utilizing supercritical geothermal systems: a review of past ventures and ongoing research activities

Introduction High enthalpy geothermal systems have been harnessed for electrical power generation for over a 100 years. While the classification scheme for low, medium, and high enthalpy systems varies for different authors (Axelsson and Gunnlaugsson 2000; Benderitter and Cormy 1990; Hochstein 1990; Kaya et al. 2011; Muffler and Cataldi 1978; Nicholson 1993), reservoir temperatures above 150–225 °C are considered to be able to provide high enthalpy fluids. To date, most developed geothermal systems have temperatures of 150–300 °C. Higher temperature geothermal systems (T > 250 °C) are almost always Abstract