Harnessing Pumped Hydro for Decarbonisation: Spain's Strategic Opportunity
Pumped hydroelectric storage is recognised as one of the most vital long-term energy storage technologies, especially in the context of decarbonising the national grid. Despite its critical importance, this technology has not received the level of attention or investment it warrants, which could hinder Spain's renewable energy transition. Spain faces a unique opportunity to develop several gigawatts of pumped hydro facilities that offer significant competitive advantages for its energy system.
Recent insights from an EY Spain report emphasise that the development of 4 GW of pumped hydro capacity, included in the Spanish National Integrated Energy and Climate Plan (PNIEC), is crucial for system flexibility and energy security. However, insufficient focus and funding threaten to delay or even prevent the realisation of these projects on time. The report highlights the stark disparity in subsidies between battery storage and pumped hydro, with batteries receiving up to 50 percent of capital expenditure support compared to only 8 percent for pumped hydro. This imbalance distorts the competitive landscape and risks undermining technological neutrality in grid stability strategies.
Expert analysis from EY Spain's Antonio Hernandez and other industry stakeholders emphasises that strategic focus and policy support are essential for harnessing the full potential of pumped hydro. The technology provides largescale, longduration storage, capable of balancing intermittent renewable generation and maintaining grid stability during peak demands. Its advantages are not limited to energy storage but extend to supporting ancillary services such as frequency regulation and reserve provision, which are vital for integrating higher shares of renewables.
Policy coherence and targeted incentives are necessary to facilitate the rapid expansion of pumped hydro plants. Madrid's recent legislative measures, including Royal Decree Law (RDL) 7/2026, signal a move towards enabling largescale infrastructure projects. Nonetheless, stakeholders warn that without active support and prioritisation, Spain risks falling behind other European nations that are investing more heavily in such strategic assets. Developing pumped hydro capacity aligns with broader objectives for energy independence, system resilience, and the decarbonisation of industry and transportation sectors.
In summary, Spain's geographic and technological potential positions it advantageously to become a leader in pumped hydro storage. Accelerating development through equitable funding, supportive legislation, and strategic planning could ensure a reliable, flexible, and sustainable energy future for the country. The realisation of these projects marks a critical step in achieving decarbonisation targets and securing a competitive edge in Europe's evolving energy landscape.