Comprehensive assessment of four volcano-hosted geothermal fields with relation to tectonics and faults in El Salvador

Abstract

Geothermal systems have noteworthy prospects for replacing the reliance on fossil fuels. El Salvador, located in a tectonically active region, supplies 25 percent of the annual electricity demand from two hosted volcanic geothermal fields. This contribution may be increased by up to 40 percent by developing two additional explored geothermal areas. Although El Salvador has a high potential for geothermal energy, studies have yet to be conducted to explore the characteristics and differences of the current geothermal fields. This study summarizes current information on the leading explored geothermal areas in El Salvador. We compared the features of the four most studied geothermal areas using regional and local tectonics, representative drilled-well lithology, hydrothermal alterations, and the resistivity structure along the magnetotelluric profile. Our results show that regional tectonics and local fault systems mainly control the characteristics of the geothermal reservoirs in El Salvador. The likelihood of identifying fractured geothermal reservoirs increases significantly in areas where the local fault system differs from the El Salvador Fault Zone (ESFZ) trend. Fractured areas adjacent to volcanic structures with substantial meteoric water recharge are highly effective geothermal energy sources. Our study enhances the understanding and exploration of the geothermal resources of El Salvador.