Powering Europe’s net zero future: Why pumped storage hydropower is vital
Europe’s transition to renewable energy is gathering pace, but one technology will be crucial in helping us achieve a stable, sustainable energy system: pumped storage hydropower (PSH). The recently published 2025 World Hydropower Outlook highlights just how important pumped storage will be in meeting Europe’s ambitious net zero targets.
Pumped storage: Europe’s renewable battery
Europe increasingly relies on wind and solar power, but their intermittent nature brings significant challenges. A proven solution lies in pumped storage hydropower — a mature technology that effectively acts as a massive, rechargeable battery. PSH stores excess renewable energy by pumping water uphill, releasing it to generate electricity exactly when it’s needed, providing reliable, flexible power on demand.
Currently, Europe has around 55 gigawatts of pumped storage capacity. Yet, according to the Outlook, we must more than double this capacity by 2050 to reliably support the EU’s energy transition and achieve net zero (p. 24).
Tackling Europe’s ageing hydropower infrastructure
Europe faces an urgent infrastructure challenge: nearly 70 percent of our pumped storage facilities are over 40 years old. These ageing plants need significant modernisation to remain efficient and safe (p. 22). Upgrading existing facilities offers a practical, cost-effective, and rapid route to increasing renewable storage capacity compared to building entirely new plants.
This need for modernisation is also a chance to introduce digital technologies — such as artificial intelligence, more sophisticated predictive maintenance and improved remote monitoring — to boost operational efficiency and minimise down time.
Barriers to new pumped storage development
Despite strong support from developers and grid operators, Europe’s progress on new pumped storage hydropower projects remains slower than desired. High upfront investment — typically exceeding £1 billion per gigawatt of installed capacity — can discourage potential investors. Complex permitting processes, lengthy project timelines, construction risks, and limited availability of specialist contractors and equipment also hold back development.
The Outlook contrasts Europe’s slower pace with the rapid pumped storage growth seen in countries with centralised economies, such as China. However, positive policy changes are emerging. For instance, the UK’s introduction of a ‘cap and floor’ financial model seeks to strike a balance by giving investors greater certainty, while ensuring affordability for consumers and taxpayers.
Addressing these barriers will be crucial if Europe is to fully harness pumped storage’s potential for a secure, renewable energy future.
Sustainability is non-negotiable
The Outlook emphasises that Europe’s pumped storage expansion must prioritise sustainability. In a region where environmental regulations and public expectations are high, careful planning, rigorous environmental assessments, and meaningful engagement with local communities are crucial.
Digital innovation powering progress
Europe is uniquely placed to lead in hydropower digitalisation. The Outlook underscores the transformative impact of digital solutions on pumped storage facilities (p. 46). Digitalisation doesn’t just make pumped storage operations more efficient — it significantly reduces environmental impacts and operational costs.
The question is pace
Across Europe, the need for grid-scale storage is widely recognised. The challenge isn’t awareness — it’s action. Governments and energy providers understand that without substantial investment in pumped storage, the transition to a low-carbon energy system won’t be achievable or reliable. The real question now is how quickly we can deliver the infrastructure needed to support it.
At AECOM, we’re committed to supporting this important transition. With our global expertise and local knowledge, combined with a focus on sustainability and innovation, we’re ready to help Europe accelerate the rollout of pumped storage.
Explore the full 2025 World Hydropower Outlook here.
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