(Salzgitter, Germany) – Salzgitter Flachstahl GmbH and Zelestra have signed a long-term power purchase agreement (PPA) for 158 gigawatt-hours of solar power per year. Under the agreement, Zelestra will construct and operate two hybrid photovoltaic (PV) plants with a combined installed capacity of 147 megawatts. The plants will be located in Brandenburg and Thuringia. Excess solar power will be stored directly in connected batteries (79 MW / 237 MWh) at each plant, which – also constructed by Zelestra – will be managed and operated by the Salzgitter Group. According to the company, this allows them to align their electricity supply with their electricity demand through the use of storage.
Decarbonization of steel production
For Salzgitter Flachstahl, part of Salzgitter AG, hybrid power purchase agreements (PPAs) are "an important building block" for meeting the increasing demand for green electricity for the long-term transformation of steel production. Salzgitter AG is currently converting its iron production from CO2-intensive, coking coal-fired blast furnaces to the low-CO2 direct reduction (DRI) process using hydrogen. Within the framework of the "Salcos" (Salzgitter Low CO2 Steelmaking) program, sponge iron is produced from iron ore in a direct reduction plant. This is then used in an electric arc furnace to produce crude steel for further processing. "The combination of solar energy and battery storage gives us the opportunity to procure renewable energy for our industrial processes on demand and at competitive prices," says Marco Hauer of Salzgitter Flachstahl GmbH. The agreement supports the decarbonization of steel production and contributes to "securing the competitiveness of the Salzgitter site."
Visualization of the 99 MW battery storage system that Zelestra is planning in Hilgermissen. © Zelestra
The Spanish company Zelestra Corporación, SAU (formerly Solarpack) has been owned by the Swedish private equity firm EQT AB since 2021. The company develops photovoltaic (PV) and wind farms, large-scale battery energy storage systems (BESS), and green hydrogen projects. It has offices in the USA and Italy. It entered the German market in 2024 and currently has offices in Berlin, Hamburg, Düsseldorf, and Rostock. In addition to the PV systems and BESS for Salzgitter AG, Zelestra, in cooperation with Centrica Energy, is currently planning a 99 MW stand-alone battery storage facility in Hilgermissen, Lower Saxony, south of Bremen. Construction is scheduled to begin in 2027, with commissioning planned for the second half of 2028.
Photo above
Zelestra's first photovoltaic power plant in Germany has been feeding electricity into the grid since August 2026. The plant, with an installed capacity of 27,5 megawatts, is located in Klevenow, west of Greifswald (Mecklenburg-Western Pomerania), and its annual yield is projected at 28.700 megawatt hours. © Zelestra
