The Sunfire GmbH project, funded by the German Federal Ministry of Education and Research under grant 03WIR2305C, ran from 1 May 2020 to 31 October 2022. It was part of the larger consortium CF06_2, whose goal was to design a functional model for decentralized production of green ammonia. Sunfire led the effort, collaborating with other partners in the consortium to develop a plant concept that could be coupled directly to a newly built or existing wind farm, optionally combined with a solar field, and operate autonomously without incurring electricity tax or the EEG surcharge.
The technical deliverables focused on a 16 MW wind/solar installation feeding a 5 MW solid‑oxide electrolyzer (SOEC). The electrolyzer was sized to produce approximately 450 000 kg of hydrogen per year, which would be converted into 2 500 t of ammonia annually via the Haber–Bosch process. The plant design emphasized cycle durability and partial‑load capability, allowing the system to absorb wind power fluctuations through dynamic operation or by employing thermal, electrical, or chemical energy storage. A key objective was to minimise storage requirements, thereby reducing capital costs while maintaining continuous ammonia output.
Work packages within the project addressed several critical aspects. The adaptation and reassessment of system data (AP CF06_2.3.1) ensured that the plant model reflected realistic operating conditions. Energetic assessments of synthesis gas generation (AP CF06_2.3.2) quantified the overall efficiency of the conversion chain. Handling of dark periods (AP CF06_2.3.3) examined strategies to maintain production during low‑wind intervals. Component specification (AP CF06_2.3.4) defined the technical requirements for electrolyzers, fuel cells, and heat exchangers, while the economic analysis (AP CF06_2.3.5) evaluated levelised cost of ammonia (LCOA) and operating expenses across three potential sites in Mecklenburg‑Vorpommern. The project also produced flexible process flow diagrams and a flexible plant concept that could be adapted to varying renewable energy supply profiles.
The results demonstrated that a 16 MW renewable input could sustain a 5 MW SOEC and deliver the targeted hydrogen and ammonia volumes. The plant concept achieved high utilisation of renewable electricity, with dynamic operation reducing the need for large storage capacities. The economic assessment indicated that the proposed configuration could achieve competitive LCOA values, contingent on local electricity procurement costs and the integration of storage solutions. The study also highlighted the importance of component durability and partial‑load performance for long‑term operation.
Overall, the project delivered a comprehensive concept for a decentralized green ammonia plant that balances technical feasibility, economic viability, and flexibility to accommodate renewable energy variability. The collaboration within the CF06_2 consortium, led by Sunfire, combined expertise in electrolyzer technology, process modelling, and economic analysis, culminating in a design that could be scaled to industrial production while maintaining continuous, autonomous operation.