IT MAY NOT GRAB the headlines like wind turbines or solar panels, but pumped storage hydropower (PSH) is quietly doing the heavy lifting of the energy transition. Providing over 90% of the world’s long-duration energy storage, it’s the unsung backbone of renewable electricity systems from Europe to Asia.
This September, pumped storage finally takes centre stage. The International Forum on Pumped Storage Hydropower will be held on 9–10 September 2025 at UNESCO’s Paris headquarters, bringing together global decision-makers for an unprecedented highlevel summit focused solely on PSH.
The event is co-hosted by the Government of Indonesia, UNESCO, and the International Hydropower Association (IHA), with a clear ambition: to scale up storage capacity worldwide and place PSH at the heart of energy planning. In a world racing to decarbonise, that ambition couldn’t be more timely.
Bringing storage to the fore
The Forum is designed to bridge the worlds of policy, finance, and engineering, convening leaders from across continents. Delegates will include government ministers, utility CEOs, multilateral banks, investors, and grid operators, all gathered to answer one big question: how do we deliver the 1500GW of energy storage the world needs by 2030?
And while the energy industry buzzes with talk of batteries and hydrogen, the Forum is a reminder that one of the most bankable, proven technologies already exists. Pumped storage uses off-peak electricity to pump water uphill, then releases it to generate power when demand surges – providing clean, dispatchable energy at scale.
Yet despite its track record, PSH has been underrepresented in policy and public debate. Development timelines, regulatory hurdles, and a general lack of awareness have left it underutilised. The Forum’s mission is to shift that dynamic.
Two bays to reset the agenda
The Forum’s programme, developed by IHA and its partners, is a blend of high-level vision setting and detailed technical sessions.
Day One – Tuesday, 9 September
Opens with “Pump It Up! Powering a Decarbonised World”, a keynote session setting the strategic context.
Regional focus sessions will dive into PSH trends in East Asia, North America, Europe, India, and Australia.
Panels will address procurement models, environmental standards, and project design for water-energy resilience.
The day closes with a high-profile session titled “Pumped for Power!”, followed by a reception.
Day Two – Wednesday, 10 September
- Focuses on scaling, finance, and innovation.
- Panels on climate-linked infrastructure, storage-ready turbines, brownfield repowering, and flexible grid integration.
- A global stakeholder forum will help align goals across industry, governments, and development banks.
- The Forum concludes with closing reflections and next steps.
Tools, maps, and strategic insights
To support real-world outcomes, the Forum draws on an expanding set of planning tools and publications:
- The Pumped Storage Hydropower Tracking Tool, an interactive global map showing planned and operating projects.
- The Hydropower Sustainability Standard, which helps governments and developers evaluate PSH performance against environmental and social criteria.
- Key reports like Enabling New PSH and the World Hydropower Outlook 2025, which highlights: over 600GW of PSH now in development; hydropower supplying 14.3% of global electricity; 8.4GW of PSH commissioned in 2024 alone.
Together, these tools help governments and investors make better decisions and identify where pumped storage can be fast-tracked or modernised.
A platform with serious backing
The Forum will be chaired by high-profile leaders from across the energy, water, and environment sectors. Key voices include:
- Malcolm Turnbull, former Australian Prime Minister and current IHA President, who has called PSH “more important than ever” in a renewables-dominated energy system.
- Representatives from IRENA, UNIDO, and the Hydropower Sustainability Alliance.
- Industry players, major utilities and grid operators.
This broad base reflects the growing consensus that PSH isn’t a legacy technology – it’s a critical enabler of future flexibility.
Not just talk – a mandate for action
While this is the first high-level global Forum dedicated to PSH, it builds on years of preparatory work. Since 2020, the IHA and US Department of Energy have helped convene technical working groups and launch the Global Alliance for Pumped Storage (GAPS) – now including over 50 agencies and governments. But until now, the technology lacked the singular political spotlight that Paris 2025 will provide.
The Forum’s core objective is to unlock investment, de-risk development, and support countries in incorporating pumped storage into national energy strategies.
A pivotal moment
The timing is no accident. With climate targets looming and energy systems increasingly volatile, long-duration storage is essential – not optional.
PSH offers a unique blend of benefits:
- Grid reliability in renewable-heavy systems.
- Seasonal flexibility and reserve capacity.
- Water-energy co-benefits, supporting drought resilience and multi-use infrastructure.
The Forum’s goal is to ensure these attributes are recognised not just by hydropower professionals – but by treasury departments, climate ministers, and infrastructure planners worldwide.
From backbone to frontline
Pumped storage has always been a steady presence behind the scenes. This September, it moves to the frontline of global energy dialogue.
By bringing together the full ecosystem of stakeholders – from government to grassroots, turbines to treaties – the International Forum on Pumped Storage Hydropower signals a shift in how we plan the clean energy future.
For the hydropower sector, it’s a defining moment: a chance to reassert relevance, drive investment, and lead in the era of renewables. And for the wider energy community, it’s a timely reminder that the technologies we need aren’t always the newest –they’re often the most proven.
For more information www.pumpedstorageforum.com
This article first appeared in International Water Power magazine.
