Augmenting grid stability through Low-head Pumped Hydro Energy Utilization & Storage (ALPHEUS)
Research Project, 2020 – 2024

With a growing share of intermittent renewable energy sources grid stability can be maintained, and flexibility enhanced, by applying pumped hydropower energy storage. ALPHEUS will improve reversible pump/turbine (RPT) technology and adjacent civil structures needed to make pumped hydro storage economically viable in shallow seas and coastal environments with flat topography.

Three promising technologies will be considered:

●Shaft-driven variable-speed contra-rotating propeller RPT – avoiding guide vanes in a two-way device improves overall efficiency;

●Rim-driven variable-speed contra-rotating propeller RPT – rim driven configuration avoids the complexity of a shaft assembly, decreasing noise, vibrations, switching time, and maintenance costs;

●Positive displacement RPT – fish friendly and seawater-robust, low cost technology.

ALPHEUS plans stepwise development, starting by validating current assumptions in the lab and optimizing efficiency with numerical simulations. Based on results, two of these technologies will be chosen and functionality will be demonstrated for working models under realistic circumstances. Finally, a reasoned and quantified assessment of these two technologies will be delivered for further development into full scale prototype. Combining current state-of-the-art and expertise of the partners ALPHEUS expects to reach round-trip RPT efficiency of 0.7 to 0.8. Fatigue resistance of mechanical and civil installations will be addressed, which occur with switching between pumping and turbining modes within 90-120 seconds. ALPHEUS will address environmental aspects, including fish friendliness, scenery and land use, juxtaposed with the ability of decentralized pumped hydro storage to stabilize the grid over a range of timescales and therefore allow higher penetration of intermittent renewable energy supplies. This will result in a methodology for assessing potential sites for pumped low-head and ultra-low head energy storage.

EU Horizon 2020 contract number 883553.

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Håkan Nilsson (contact)

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics

Jonathan Fahlbeck

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics

Saeed Salehi

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics


Advanced Design Technology Ltd

London, United Kingdom

Blue Turbines


Delft University of Technology

Delft, Netherlands

Ghent university

Gent, Belgium

IHE Delft Institute for Water Education

Delft, Netherlands

Norwegian University of Science and Technology (NTNU)

Trondheim, Norway

Technische Universität Braunschweig

Braunschweig, Germany

Tuscia University

Viterbo, Italy

Universite de Pau et des Pays de L'Adour

Pau, France

University of Stuttgart

Stuttgart, Germany

Uppsala University

Uppsala, Sweden


European Commission (EC)

Project ID: EC/H2020/883553
Funding Chalmers participation during 2020–2024

Related Areas of Advance and Infrastructure

Sustainable development

Driving Forces


Areas of Advance

C3SE (Chalmers Centre for Computational Science and Engineering)


Innovation and entrepreneurship

Driving Forces


More information

Project Web Page

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