Prospects for Power Generation of the Doublet Supercritical Geothermal System in Reykjanes Geothermal Field, Iceland

Supercritical geothermal resources are in the preliminary exploration stage as a new type of clean energy and there are no practical utilization projects. The IDDP-2 well at Reykjanes geothermal field in Iceland encountered supercritical geothermal conditions in 2017, with a maximum temperature of 535 degrees C. The system is still in the field experiment stage and no exploitation work has been carried out. Hence, a hypothetical doublet geothermal system was simulated based on IDDP-2 to study the power generation potential and favorable operating conditions for future development of supercritical geothermal resources. A multiphase flow model is established to predict the fluid and heat flow characteristics. Furthermore, sensitivity and economic analyses were performed to evaluate the expected commercial and environmental benefits of the supercritical geothermal system. The results show that the system's evolution could be briefly divided into three stages according to the temperature variation. The power generation ranges between 5.4 MW similar to 16.5 MW, and the levelized cost of electricity (LCOE) is 0.02 $/kWh. In addition, the system can reduce CO2 emissions, which are 1.2 similar to 7.75 Mt less than that of fossil fuel plants with the same installed capacity. The results prove the great development potential and commercial competitiveness of the supercritical geothermal system.