Geothermal Energy as Firm Power for Copper Mining in Southern Peru: A Probabilistic Techno-Economic and Multi-Criteria Assessment

Copper mining in southern Peru needs firm, low-carbon electricity but relies on a hydro-dominated grid whose marginal cost rose from about 30 to 200 USD/MWh during the 2022–2023 drought; no study has linked the region’s geothermal resources to this demand. We assessed how much, at what cost and by when eight fields of the Southern Volcanic Axis could supply the incremental mining demand of the Arequipa–Moquegua–Tacna corridor in 2026–2040. We combined a Monte Carlo simulation of correlated exploration success and development schedules, a system levelized cost of electricity (LCOE) delivered to the mine, and an AHP–TOPSIS multi-criteria analysis. The deployable resource averages 691 MWe (P90: 343 MWe). Installable capacity is zero before 2033 and reaches a median of 673 MW in 2040, covering base-case demand with 76% probability (56–62% with schedule delays). The median LCOE of the reference field, 111 USD/MWh, is lower than diesel backup and, in 71% of cases, than solar–wind with storage, but higher than natural gas and the grid. Geothermal energy ranks first while the economic weight stays below 37% and its supply security is rated at least 4.02 out of 5. Exploration risk and development time, not resource size, constrain this medium-term firm supply option.