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Join UsHydropower in Europe
Hydropower has a long tradition in Europe, contributing significantly during the first half of the last century to the welfare and industrial development of most countries across the European area. Today hydropower has become a key enabler of Europe’s clean energy transition, offering its unique ability to deliver dispatchable zero-carbon power, long-term storage, grid resilience, water-security co-benefits, and industrial competitiveness. Its dispatchable nature is
crucial for integrating variable renewables and stabilizing the grid, while modern technologies enable nature-positive operation. Today, almost 650 TWh are generated in an average hydrological year, which equates to about 65% of the economically feasible hydropower potential within European region including Turkey (Figure 1).
Figure 1: Evolution of yearly production and installed capacity of hydropower in Europe since 2006 (according to Hydropower & Dams World Atlas 2024).
Since a few years, the yearly production of hydropower stabilizes near 650 TWh and the total installed capacity near 230 GW. It should be noted, however, that the yearly hydropower production is also influenced by the hydrological situation each year as for example can be seen by the very dry year 2022.
In the European Union (EU), the hydropower installed capacity in 2023 was 152 GW and generated approx. 300 TWh (pumped storage powerplants adsorbed 43 GWh and generated 42 TWh in 2022), which is the second highest share in electricity production from renewable energy sources, after wind energy. In the EU hydropower contributes with 16% to the total electricity production whereas in the European region with more than 20%.
Within the European Union, hydropower accounts for around 16% of total electricity generation, and more than 20% across the wider European region, making it the second-largest renewable electricity source after wind.
Figure 2: Generation and extension potential of hydropower in countries in the European region
(according to Hydropower & Dams World Atlas 2025). Countries having developed less than 50% of their
economical feasible potential (assuming market conditions have demand for it) are highlighted. The
share of hydro in the electricity generation is indicated for the countries with a share more than 20%.
As Europe accelerates electrification and expands wind and solar deployment, the need for flexibility and storage is increasing rapidly.
Flexible and dispatchable renewable generation
Short- and long-term energy storage
Frequency control and ancillary services
Security of supply during prolonged low wind and solar periods
During extended “Dunkelflaute” events — when wind and solar output remain low for sustained periods — hydropower and pumped storage are essential to stabilising the grid and preventing supply disruptions.
Looking ahead, hydropower will remain a key enabler of a secure, resilient and climate-neutral European energy system. Modernisation of existing assets, sustainable expansion of storage capacity and supportive regulatory frameworks will be essential to maximise its contribution in the decades to come.
Between 2016 and 2022, investment levels declined due to prolonged low wholesale electricity prices, excess conventional generation capacity and weak carbon price signals. Under these conditions, the system value of hydropower flexibility was not fully recognised.
The energy crisis since 2022 has fundamentally shifted this perspective. The strategic importance of storage, resilience and domestic renewable generation has become clear. As a result:
This renewed momentum reflects hydropower’s central role in ensuring Europe’s long-term energy security.
Climate change will significantly influence hydropower development in Europe. Altered precipitation patterns, increased sediment transport and more frequent extreme events will affect water availability and infrastructure resilience.
At the same time, reservoirs associated with hydropower plants will increasingly contribute to climate adaptation, flood management and drought mitigation — reinforcing hydropower’s multi-purpose value within the Water–Energy–Food nexus.
Between 2016 and 2022, investment levels declined due to prolonged low wholesale electricity prices, excess conventional generation capacity and weak carbon price signals. Under these conditions, the system value of hydropower flexibility was not fully recognised.
Types of Hydropower Plants
In general hydropower plants, can be characterised according to the criteria arrangement, gross head, possibility of storage and types of turbines as shown in Figure 3.
Run-of-river powerplants have only little storage behind the gated weir and the produced energy directly depends on the flow quantity in the river. Run-of-river hydropower plants typically provide baseload power, since the hydrological forecast is sufficiently good for the timescales required in the electricity market. However, if arranged in a cascade along a river, run-of-river plants may have some short-term storage possibilities (typically less than one-hour dynamic cycle) and this allow for some short-term adaptation to demand, especially for ancillary services such as frequency and voltage control.
Storage power plants are based on impounding water in a reservoir behind a dam. Storage plants have the advantage that they are less dependent on the natural flow of water; in fact, according to their storage capacity, they can operate independently of the hydrological inflow by storing water during the wet season and using it the dry season and even inter-annual. In other words, they can easily store potential energy to be converted into electrical energy when needed in a flexible way.
Pumped-storage hydropower plants operate with two reservoirs, a lower and an upper. The two reservoirs are connected to each other through tunnels or penstocks. A pumped-storage plants move waters between the two reservoirs. In production mode, the plant operates like a conventional hydroelectric plant: water is released from the upper reservoir through the turbines to generate electricity; In pumping mode, electrical energy from the grid is used to pump the water from the lower reservoir to the upper one (usually during off-peak periods using surplus electricity generated by base-load power plants and solar and wind). Both enable balancing from daily to weekly and from daily to seasonal timescales and delivers critical grid services such as inertia, frequency response, and black start capabilities, all essential as variable renewables expand.
Hydropower in Europe, and indeed worldwide, has many advantages such as:
Due to massive development of solar-PV (infra-day flexibility) and wind power (weekly flexibility) hydropower contributes to more than 30% of the flexibility services, ensuring that during “Dunkelflaute” events, as experienced in November 2024, the grid can be stabilized avoiding catastrophic blackouts. The trend of required flexibility services is strongly increasing in EU as shown in Table 1. Thus, storage and pumped storage hydropower will be most vital in Europe to safely overcome severe and critical winters with “Dunkelflaute” also in case of potential gas supply problems. Today, European Hydropower reservoirs hold hundreds of TWh of stored energy and pumped storage totalizes ~46 GW of flexible power capacity. Multiple prospective analyses indicate the need to at least double to quadruple this storage capacity by 2050, aligned with the 2025 PSH Paris Pledge of IHA.
| Electric Power Capacity in EU (GW) | 2000 (GW) |
2012 (GW) |
2022 (GW) |
2025 (GW) |
|---|---|---|---|---|
| HYDRO | 135 | 145 | 153 | 150 |
| SOLAR PV | ≈ 0 | 71 | 206 | 345 |
| WIND | 12 | 97 | 204 | 230 |
| GAS + COAL + OIL | 340 | 425 | 380 | 315 |
| NUCLEAR | 125 | 113 | 100 | 96 |
| Other … | … | … | … | … |
| TOTAL | 605 | 845 | 1 055 | 1 150 |
Run-of-river hydropower plants typically provide baseload power, since the hydrological forecast is sufficiently good for the timescales equired in the electricity market.
Figure 4: Installed capacity in MW under construction since 2005 (according to Hydropower & Dams
World Atlas 2025 without Turkey).
However, in view of environmental and socio-economical constraints, the partial use of this remaining potential is extremely challenging and can be reached only through innovative and sustainable solutions for new hydropower plants.
Additionally, regulatory uncertainty related to the renewal of hydropower concessions is hindering investment and delaying the development of hydropower projects in some European countries.
Future Role of Hydropower in Europe as a Catalyst for the safe Energy Transition
Hydropower plays an important role today and will become even more important in the coming decades, since hydropower can be a catalyst and enabler for a safe energy transition in Europe.
The ambitious plan for energy transition in Europe seeks to achieve a low-carbon climate-resilient future in a safe and cost-effective way, serving as a worldwide example. The key role of electricity will be strongly reinforced in this energy transition. In many European countries, the phase out of nuclear and coal generation has started with a transition to new renewable sources comprising mainly of solar and wind for electricity generation. However, solar and wind are variable energy sources and difficult to align with demand. Hydropower already supports integration of wind and solar energy into the supply grid through flexibility in generation as well as its potential for storage capacity. These services will be in much greater demand to achieve the safe energy transition in Europe, and worldwide.
Hydropower, with its untapped potential, has all the characteristics to serve as an excellent catalyst for a successful energy transition. However, this will require a more flexible, efficient, environmentally and socially acceptable approach to increasing hydropower production to complement wind and solar energy production. In particular through the vision:
Increasing hydropower production through the implementation of new environmentally friendly, multipurpose hydropower schemes and by using the hidden potential in existing infrastructure.
Increasing the flexibility of generation from existing hydropower plants by adaptation and optimization of infrastructure and equipment combined with innovative solutions for the mitigation of environmental impacts.
Increasing storage by the heightening of existing dams and the construction of new reservoirs, which have to ensure not only flexible energy supply, but which also support food and water supply and thus contribute to the Water-Energy-Food NEXUS and achievement of the Sustainable Development Goals of the United Nations.
Strengthening the contribution of flexibility from pumped-storage power plants by developing and building innovative arrangements in combination with existing water infrastructure.
Climate change will be an important issue for hydropower development in Europe. The effect of climate change will not only change the availability of water resources in time but will also change the behaviour of the catchment areas through increased sediment yield and more frequent natural hazards, thus endangering hydropower production in the future. It is recognized that the reservoirs associated with hydropower plants will have to contribute more and more towards the mitigation of climate change effects.