Following nature’s lead: Chemical energy storage

sunfire has developed a technique for efficient methane (CH4) production. The gas is produced using the basic educts carbon dioxide (CO2) and water (H2O) in combination with electrical energy from regenerative sources, and can be fed directly into the existing natural gas network. Methanation facilitates the storage and transport of renewable energies using the existing natural gas grid.

sunfire plans to produce methane using efficient high-temperature steam electrolysis. The technique is still under development, but has the potential to increase overall process efficiency from 55 % to about 80 % (i.e. 80% of the electrical energy used contributes to the lower calorific value of the methane produced).

sunfire already builds power-to-gas systems based on existing water electrolysis technology, with an efficiency of around 55% achieved. Systems are set up to allow for the retrofitting of steam electrolysis modules and corresponding increase in efficiency at a later date. Steam electrolysis is due to be available from 2016 onwards.

Bilfinger Industrial Technologies / sunfire – fact sheet

Technical data

Power output:

250 kW up to several MW, equivalent to


600 Nm³/d up to several thousand Nm³/d

Process pressure:

max. 60 bar

Process temperature:

max. 800 °C


approx. 80 %

Rate of carbon utilization:

min. 98 %

GHG mitigation potential:

min. 85 %

Typical areas of application/users
  • Wind and solar power station operators (storage of excess electricity generated using wind and solar power)
  • Grid operators (energy transport outside of the power grid)

Key benefits
  • Existing natural gas grid can be used as an efficient and large, area-wide energy storage (“chemical pumped storage power station”)
  • Opportunity to recycle vast amounts of CO2 (alternative to CCS (Carbon Capture and Storage))
  • Synthetic natural gas is produced without the usage of biomass, hence there is no competition to scarce resources
  • Can be used for grid stabilization