One of the main strategies to maximize renewable energy penetration in electrical systems is to optimize their dispatchable capacity. One of the benefits of geothermal energy, as a renewable energy source, is its high dispatchability. The isolated electrical energy system of Tenerife (one of the 8 islands of the Canary Archipelago) is highly dependent on fossil fuels. The advanced state of maturity of the geothermal exploration of Tenerife positions the island with a high degree of probability as one of the few regions in Spain with high-enthalpy geothermal resources. This paper reports on a study undertaken of the island’s geothermal potential which involved calculation of the heat stored in geothermal reservoirs and the identification of zones of interest for exploitation of this resource and its energy capacity. Among the results obtained, 3 areas of interest were identified for the exploitation of geothermal energy with a total installable electrical power of 117.8 MW, which would increase the renewable contribution to the island’s daily demand by over 20% as well as contribute to maximizing the flexibility and stability of the electrical energy supply in a scenario of high renewable energy penetration.