COP30: Hydropower and Energy Storage

Recommendations

• Increase flexibility. Develop solutions that enhance the ability to regulate power generation while safeguarding environmental values.
• Expand pumped storage. Upgrade existing facilities to pumped-storage operation to strengthen energy storage and system balancing.
• Focus on technical improvements. Invest in research on turbines, control systems and digital operation technologies.
• Assess and mitigate environmental impacts. Document ecosystem effects and integrate environmental measures into refurbishment projects.
• Adapt market frameworks. Introduce regulations and pricing mechanisms that reward flexibility and storage capacity.

Current situation

The global energy transition now underway requires the provision of reliable, sustainable energy at an affordable cost. To achieve the Paris Agreement targets, we must deploy technologies that already exist — and hydropower is the most mature and efficient renewable energy source available.

Most existing hydropower systems were designed for a stable energy mix with multiple flexible generation sources. In the future, the energy system will be far more weather-dependent, dominated by wind and solar power, and with less inherent storage capacity. This places new demands on hydropower’s role as a balancing and storage resource.

Many hydropower plants in Europe and North America are ageing and were built to older standards. Comprehensive upgrading and modernisation are needed to ensure future operation, enhance flexibility and maintain environmental performance. At the same time, new measures must balance technical optimisation with the protection of nature and local communities.

Solution

Hydropower is currently the world’s largest source of renewable electricity, producing more energy than wind and solar combined — and, according to the IEA, global hydropower generation is expected to double by 2050. However, its most important role in the future will likely be to enable the large-scale integration of variable energy sources such as wind and solar.

As the power system shifts from fossil fuels to intermittent renewables, there will be an increasing need for balancing and energy storage across time scales ranging from seconds to days, weeks and seasons. This requires system-level analyses, updated market designs and optimised operational planning.

No other renewable technology offers the same combination of flexibility, controllability and storage capacity at a comparable cost. Pumped storage — which accounts for over 90 % of all grid-connected energy storage capacity worldwide — is also essential for achieving a renewable energy future. The remaining untapped hydropower potential is primarily located in Asia, Latin America and Africa, though there is still some potential in Europe and North America.

Together, these measures will make hydropower more sustainable and increase public acceptance. Modernisation can deliver significant capacity upgrades, more flexible operation and improved use of storage resources. At the same time, refurbishment should include effective environmental measures such as two-way fish migration systems, ecological flow releases and other initiatives to improve the ecological status of regulated rivers.

Hydropower reservoirs can also provide valuable co-benefits, including flood control, irrigation, water supply, navigation and recreation.