Making use of the complementarity of hydropower and variable renewable energy in Latin America : a probabilistic analysis

Latin America is one of the regions most vulnerable to the effects of climate variability on hydropower generation. Hydropower is the backbone of the Latin-American power system and a key technology for ensuring low-carbon power generation in the region. Despite its importance, our understanding of the impact and likelihood of seasonal variability and of long-term phenomena such as the El Niño Southern Oscillation (ENSO) on hydropower is limited. There is an essential need to understand how likely these effects are and to identify measures to counterbalance them. A combination of wind, solar, and hydropower offers the potential to mitigate the impact of climate variability on renewable power generation and thus improve its reliability. Here we present a modeling framework to quantify the potential benefits of such combination. The modeling framework relies on a meteorological reanalysis dataset, large-scale renewable power generation models, and statistic models. We consider the countries with the largest hydropower capacity in the region, namely Argentina, Brazil, Colombia, Mexico, and Venezuela. We examine whether the probability of a production deficit is reduced when all renewable resources are combined compared to a scenario based solely on hydropower, especially during droughts. The approach presented allows for the first time an in-depth analysis of the benefits of a combined wind, solar, and hydropower-based power generation under different geographical conditions in altered ENSO phases. Our results suggest that - depending on the country and the percentile - the hydropower generated during drought ENSO phases could be up to 50% lower than that during neutral phases. The countries most affected are Colombia and Venezuela, while the reduction is somewhat less severe in Argentina, Brazil, and Mexico. Combining hydropower with variable renewable energy (VRE) offers the potential to reduce the risk of a power deficit during the 10th percentile of the driest months of the year, both in drought and neutral phases. Argentina is the country with the most effective combination of resources to mitigate a power deficit, as each MW of installed VRE generates 0.218 GWh of additional power. It is followed by Brazil and Mexico with 0.185 GWh per MW of VRE and by Venezuela and Colombia with 0.128-0.098 GWh/MW of VRE, respectively. These results can contribute to informing future decisions on capacity planning and regional transmission grids.