Upper reservoir at Uniper power plant in Happurg largely complete
Uniper is investing 250 million euros in the modernization of the long-established power plant, which is expected to resume storing and supplying electricity starting in 2028.
August 3, 2026
Source: E & M powernews
The renovation of the upper reservoir at Bavaria’s largest pumped-storage power plant is nearing completion. The state’s Minister of Economic Affairs, a member of the Free Voters party, calls it a “stabilizing force for the energy transition.”
Political fly-by at the Uniper Happurg pumped-storage power plant: Bavaria’s Minister of Economic Affairs, Hubert Aiwanger (Free Voters), got a firsthand look at the renovation work being done at the facility in the Nürnberger Land district. According to the ministry, citing the energy company, the renovation of the upper reservoir is largely complete. Work on the lower reservoir, the pressure pipelines, and the powerhouse is also proceeding as planned, the ministry said.
The power plant, which has been out of service since 2011, is scheduled to resume operations in 2028. According to Uniper, the company is investing approximately 250 million euros in the renovation. Built in 1958, the plant has four turbine sets with a total capacity of 160 megawatts and a head of 209 meters. The upper reservoir holds 1.8 million cubic meters of water, generating 850,000 kWh of electricity.
The decision to refurbish the power plant was made in June 2024. This was preceded by extensive geotechnical investigations of the upper reservoir. Localized damage to the reservoir’s base had led to the suspension of pumped-storage operations 15 years ago. Based on the geotechnical reports, “a concept for upgrading the upper reservoir was developed and refined, enabling a cost-effective return to operation,” as Uniper explains.
Four Active Pumped-Storage Sites
A double-shell sealing system was installed in the upper reservoir. A monitoring system featuring a “inspection walkway” is also intended to ensure safety. In addition, new motor-generators are to be installed. Turbines, pumps, and valves are undergoing an overhaul. Construction work on the upper reservoir is scheduled to be completed in 2027. The company aims to finish installing the pumped-storage units that same year.
“With a capacity of 160 megawatts and a storage capacity of 850 megawatt-hours, Happurg will become a cornerstone of stability for the energy transition in Bavaria following the renovation,” Hubert Aiwanger is quoted as saying in the ministry’s press release. Uniper’s investment in the Happurg site is “an important commitment” to this technology. “We must store renewable energy instead of curtailing it.” Aiwanger emphasized on this occasion that the “Riedl pumped-storage plant in the Passau district must now be built quickly.”
There are four active pumped-storage sites in Bavaria: Langenprozelten, Leitzach, Rabenleite, and Oberberg. Together with Happurg, they have a total capacity of around 550 megawatts and a storage capacity of 2.3 million kilowatt-hours per cycle.
Author: Manfred Fischer
