sunfire GmbH, a German energy conversion technology specialist, has developed the world’s largest commercial reversible electrolysis (RSOC) module, which delivers renewable energy on demand.

The fully integrated system converts surplus renewable energy into hydrogen (H2) which is then stored in a highly compressed form. It can then re-generate electric power when needed using the stored H2 taken from its fuel cell mode.

The system only takes a few minutes to switch from energy input to energy output mode. When in electrolysis mode, the system yields 42m3 of H2 per hour at up to 85% efficiency. When switched to fuel cell mode it delivers 50kW of electricity at up to 60% efficiency.

The module consists of a hot box, cold box, control unit and steam generator, and can also be operated in fuel cell mode in combination with cheap natural gas or biogas taken from the grid.

Nils Aldag, Chief Financial Officer (CFO) at the Dresden-based cleantech firm, signified, “sunfire is proud to have developed the world’s largest reversible electrolysis system – another important milestone as we move towards industrialisation.”

sunfire and US partner Boeing began working together in 2014, with the RSOC system developed by sunfire at its headquarters in Dresden, Germany, in cooperation with engineers from Boeing. The system has now been integrated into a US Navy microgrid test facility for further analysis.