Renewing a century-old pumped storage power plant

15 Jan 2025

The new cavern storage facility of the Rudolf-Fettweis-Werk power plant in Germany will add enough capacity to generate seven hours of nonstop energy. Our experts are leading the planning consortium.

Modernization works are underway on one of Europe’s oldest combined pumped-storage and run-of-river power plants. Constructed nearly 100 years ago on the river Murg in southern Germany’s Black Forest, the Rudolf-Fettweis-Werk plant near Forbach, Baden-Württemberg, has been operating continuously ever since. The expansion project will create urgently needed storage capacity by 2027. Upon completion, the power plant will be able to generate electricity from water stored in caverns for 30,000 households for seven hours without interruption, or to compensate for fluctuations in the power grid over a longer period.

The Rudolf-Fettweiss-Werk power plant, originally built in 1918

Tractebel leads planning consortium

Tractebel company Hydroprojekt, in a joint venture with our hydropower specialists in Germany, is in charge of the planning consortium for client EnBW (Energie Baden-Württemberg AG). Our experts have been planning the project since the first conceptual considerations in 2007. Completion is scheduled for 2027.

Since 2012, together with partner Geoconsult consulting engineers, Tractebel has prepared the design documents for all design phases, with the use of Building Information Modelling (BIM) technology since 2019. We also supported the client in the tendering and approval processes for the new power plant, as well as in the negotiations with potential bidders during the contract awards.

The construction of the new power plants began in early 2024. Tractebel is currently working on the construction design of the civil works and feeding the site with the required drawings and calculations.

BIM model of the new Rudolf-Fettweis-Werk power plant

Celebrating the start of the rehabilitation works on the 100-year-old power plant

New lower level comprises underground storage cavern and power plant

The Rudolf-Fettweis-Werk comprises two separate hydropower plants, Schwarzenbachwerk and Murgwerk. Both will be replaced by new constructions. While the existing reservoirs and the major parts of the waterways can be reused without modifications, an underground powerhouse will be built to house the new power plants. The Schwarzenbachwerk plant will use two existing reservoirs and will be operated as a pumped storage plant with a capacity of 54 MW.

Construction of the underground storage cavern and power plant, which will be connected via a tunnel to the existing lower reservoir, has begun. The new pump turbine, which replaces the century-old machinery, can be operated at variable speed. This enables the pumped storage plant to react with maximum flexibility to the demands of the power system. The water stored in the cavern will add 350 MWh of electrical storage capacity. After use in the underground power plant, the water can be transported back to the upper reservoir as needed for re-use in electricity generation. The blasting work is currently underway.

The new Murgwerk plant will basically be operated as run-of-river power plant. Three Francis turbines of different sizes and a total capacity of 21 MW will ensure optimal use of the water resources.

Excavation of the access tunnel to the powerhouse cavern

Sustainability by design

The Rudolf-Fettweis-Werk modernization project is designed with sustainability as a top priority. Social and environmental impacts during construction have been minimized due in part to the underground nature of the works, but also to extensive sustainability measures incorporated into the initial design.

“The extension and reconditioning of the hydropower plants will make the Rudolf-Fettweis-Werk fit for another 100 years of renewable energy production, even under the requirements of modern energy systems,” says Robert Achatz, Project Manager, Tractebel Hydroprojekt in Germany. “Stringent environmental considerations plus the addition of 350 MWh of storage capacity make this project a vital and sustainable addition to Germany’s energy transition. Pumped storage power plants like the Schwarzenbachwerk help to balance out irregular generation from sources like wind and solar, thereby stabilizing the grid. This allows the reduction of hydrocarbons without compromising the availability of energy for the economy and society.”

Robert Achatz, Project Manager, Tractebel Hydroprojekt in Germany

Discover our Hydropower solutions

Related news

Mareterra-banner-1

Royal inauguration of Mareterra in Monaco

On December 4, the Royal Family of Monaco officially inaugurated Mareterra, an exceptional district that expands Monaco's territory by three percent. As Owner’s...

Find out more
13 Dec 2024
AdobeStock_286969556_2

[Podast] Joining Tractebel means "opening up to the world"!

At Tractebel, around 1/3 of our employees are women. And we're aiming to have 40% women in management by 2030. In this episode of the « Engineering Angles” podcast, Daphné...

Find out more
10 Dec 2024
Steady_Energy_Reactor_Cutaway_HIGH_RES

Tractebel supports Steady Energy in developing the world’s simplest nuclear reactor for clean heating

Tractebel will assist Steady Energy, a pioneer in Small Modular Reactor (SMR) technology development, in its LDR-50 nuclear reactor design and licensing process....

Find out more
05 Dec 2024
Vue_aerienne_du_CNPE_du_Blayais_2024_YohanEspiaube_copyrights_YohanEspiaube

Completing first-of a-kind intervention: Blayais nuclear reactor’s primary elbow replacement in France

Tractebel contributes to upgrading the French nuclear fleet, which provides over 70% of France’s low-carbon electricity, to extend its lifetime beyond 40 years. Jointly with...

Find out more
12 Nov 2024