Uniting Industry Leaders for Green Hydrogen Production
WUN H2 operates as a joint venture between Siemens Financial Services, gas trading company Rießner-Gase, and utility company Stadtwerke Wunsiedel (SWW). Initiated around three years ago, the project set out to establish one of Germany’s largest green hydrogen production plants. Officially inaugurated in September 2022, the plant at Wunsiedel Energy Park now has the capacity to generate up to 1,350 tonnes of green hydrogen annually using renewable solar and wind energy. The production process relies on an electrolyzer with an 8.75-megawatt capacity.
Dr. Philipp Matthes, Joint Managing Director, states: “The Wunsiedel plant includes a two-stage compression system reaching up to 500 bars, with onsite storage and a filling station. Hydrogen will be transported by trucks to local and regional industrial clients. It can also be supplied via a pipeline to a neighboring Combined Heat and Power (CHP) facility for wood pellet production, offering an option to replace natural gas and support decarbonization. Additionally, by spring 2023, we plan to introduce a hydrogen refueling station for trucks and commercial vehicles to promote sustainable mobility.”
Hydrogen plays a pivotal role in the energy transition. The innovative Wunsiedel approach helps reduce reliance on the electricity grid. Dr. Thilo Rießner, Joint Managing Director, explains: “Our electrolyzer splits water into hydrogen and oxygen using electricity from renewable sources, making the hydrogen fully sustainable. Historically, we relied on external suppliers, often large chemical plants. Partnering with SWW and Siemens gave us the opportunity to develop a local, renewable source.”
Philipp adds: “The shareholder model combines Siemens’ technology expertise, a strong financial arm, local sales insights, and municipal backing, anchoring the project within the local community.” However, regulatory uncertainties present ongoing challenges.
Philipp elaborates: “A significant hurdle is the absence of a clear regulatory framework for green hydrogen in Europe. Discussions around the Renewable Energy Directive II are ongoing, but no official legislation exists. Without standardized definitions, the nature of green hydrogen must be contractually defined between buyers and sellers, complicating long-term planning and financial security. Despite this, we secured a non-recourse project financing agreement—possibly a first in Germany and Europe—thanks to Siemens Financial Services’ expertise.”
Thilo adds: “Securing this financing from UmweltBank, which specializes in ecological loans, was challenging. The agreement depended on projected cash flows, and banks tend to favor established technologies. Achieving competitive prices for green energy remains difficult in today’s volatile market. While Power Purchase Agreements (PPAs) traditionally ensured stable pricing, market fluctuations make such arrangements more complex.”
Planning for Growth
Looking to the future, the Wunsiedel plant was designed with scalability in mind. Production capacity could double to 17.5 megawatts, but this expansion depends on sufficient off-take and compression system capacity. Philipp explains: “We aim to capture and utilize waste heat from electrolysis and find applications for the oxygen produced. Although current demand for oxygen is limited, scaling up production will open more opportunities. One potential initiative is to supply oxygen to a nearby wastewater treatment facility to enhance energy efficiency.”
The project also focuses on converting surplus renewable energy into storable hydrogen, ensuring flexible energy loads for industrial and mobility applications. Thilo highlights: “Our plant can power up or down within ten seconds, quickly responding to changes in renewable energy production.”
Although Wunsiedel currently hosts one of the largest plants, its location in a smaller region limits future expansion. Nevertheless, the model’s broader influence could be significant if adopted by other municipalities.
Looking ahead, Thilo concludes: “Our priority is to ensure consistent and reliable production. Once operations stabilize, we’ll explore opportunities to increase output. The green hydrogen market is still developing, and expertise is evolving. It will take time to establish the processes and knowledge required for long-term success.”