Integrating renewable energy for power security under water stress scenarios due to climate change: Strategies and opportunities

Hydropower systems are vulnerable to climate change effects, mainly in the Southern Hemisphere, risking energy security and investments in emerging markets. With Brazil as the representative case, this study explores strategies to enhance the power system’s reliability and opportunities amid water stress scenarios in 2050. This work presents a high-resolution power model, which optimizes capacity and dispatch simultaneously while minimizing the costs. Findings indicate a major role of wind energy and a decline in natural gas in water stress scenarios. However, extensive wind penetration is only possible when combined with storage systems, which remain mainly reservoir-based. Also, severe cases of water stress can increase the power system cost by up to 14.9% when combined with 100% renewable systems. The moderate cost scenarios have similar optimal results to advanced costs (less costly), indicating the high competition between wind and solar alternatives. Furthermore, expanding the wind farms portfolio may lead to surplus wind energy, particularly during the dry season when energy demand is lower. Such excess energy could potentially produce 0.46 Mt of green hydrogen annually, surpassing the current industry usage of 0.33 Mt in Brazil. Effective spatial planning is crucial, particularly considering that green hydrogen production requires water, and the surplus energy predominantly comes from the Northeast, where intense drought events are frequent.