Power-to-gas (P2G) plant – excess electricity can be stored in the form of biomethane!
On behalf of Energie Steiermark Technik GmbH, we were able to participate in the realization of a trend-setting power-to-gas (P2G) plant for the coupling of hydrogen production from renewable energies.
The P2G plant is located in Gabersdorf (near Leibnitz/Styria) directly at the gas grid. Green hydrogen is produced in a PEM electrolysis system, compressed, temporarily stored and partly delivered to end users via an H2 trailer filling station and partly used for methanation of raw biogas from a neighboring biogas plant. A powerful photovoltaic (PV) system is installed to power the plant.
In catalytic methanation, biomethane with gas grid feed-in quality is produced from raw biogas, which contains about 52 v% methane and about 45 v% carbon dioxide, by adding hydrogen and using integrated gas purification processes, and is then fed into the public gas grid. Due to this process, for the first time almost the entire carbon contained in biogas is available as an energy carrier “biomethane” and the material efficiency of a biogas plant is thus almost doubled and hydrogen becomes storable in the long term and at low cost.
This represents the missing link of the energy transition, as the electrolysis and methanation technologies used thus enable the year-round conversion of excess electrical energy into biomethane that can be stored and transported.
These P2G plants can be installed regionally at numerous locations at biogas and wastewater treatment plants that are close to a natural gas pipeline and can use regionally generated surplus eco-electricity without burdening the supra-regional power grid and can also thereby significantly improve system efficiency.
However, biomethane is not only an excellent storable energy carrier, but also provides the basis for chemical synthesis processes such as fertilizer production and is therefore a true multi-talent.