Region - Water Conservancy

The relationship between water and energy is bidirectional and highly interdependent. Water is essential for energy production, while energy is critical for the whole water cycle, including urban water supply, sanitation, purification, and irrigation. The global energy crisis and water scarcity have posed severe challenges to the traditional hydropower sector. As a clean and stable renewable energy, hydropower accounts for 17%–18% of Spain's energy mix, but its development is restricted by decreasing water availability and climate change. Against this background, Spain's Law 7/2021 on Climate Change and Energy Transition strongly promotes reversible hydroelectric plants, which can serve as large-scale energy storage and improve the efficiency of water use. This paper analyzes the definition, types, and operating mechanism of reversible hydroelectric plants, as well as the relevant legal framework in Spain, involving water concessions, third-party rights, environmental protection, and administrative authorization. It points out that the key to further developing such plants lies in improving the supporting legal system to ensure legal certainty for investors and balance the goals of energy transition, water resources management, and environmental protection.