Variable renewables fortify Ecuador's power system against recurrences of drought-driven energy crises.

In 2023-2024, two successive failed rainy seasons plunged hydropower-dependent Ecuador into an unprecedented energy crisis. As rivers ran dry and hydropower generation dwindled, the Ecuadorian government had to implement daily nationwide electricity cuts throughout 2024 to keep reservoirs from emptying completely. In this Article, we show that opting for a strong build-out of solar and wind power-often criticized for their variability and purported lack of dependability-could become an important element in the fortification of Ecuador's power system against similar future droughts. Exploiting a newly identified resource complementarity, dubbed extreme-year synergy, a coupling of hydropower operation with solar and wind energy generation would safeguard reservoir levels in critical periods, largely compensate the dry-year hydropower deficit, and substantially reduce the need for thermal backup capacity and generation, quantified through a new concept, the 'indirect' capacity credit of variable renewables. The identified opportunities have ramifications for hydro-dependent nations across Latin America and elsewhere.