Power to Gas

The methanisation of excess power makes conventional power stations redundant

The expanding use of renewables creates new challenges for the power supply sector. Weather-dependant renewable energy sources, such as wind and the sun, inevitably lead to peaks in power generation. These can currently still be balanced out by reducing the output of conventional power stations. As the proportion of renewable energy grows, innovative storage technologies will increasingly gain in importance.

The German natural gas grid has immense storage capacities. This means that the production of synthetic methane from excess wind or solar power with the help of power-to-gas technology now presents real opportunities.

MicrobEnergy GmbH – a specialist in methanisation

MicrobEnergy GmbH, a member of the Viessmann Group, develops and sells microbiological products and technical system components. The company, furthermore, also specialises in process control and optimising biological systems.

Electrolysis as intermediate step

The basic principles behind power-to-gas can be described as follows: Excess power is converted into hydrogen by means of electrolysis. This is followed by what is known as the methanisation stage, in which synthetic methane is obtained from hydrogen and carbon dioxide (CO2). The required CO2 can be sourced from industrial processes, the surrounding air or biogas plants.

Microorganisms convert power into methane

MicrobEnergy uses highly specialised microorganisms, which convert hydrogen and carbon into pure methane. The microorganisms function at ambient pressure and temperature, and there are no special requirements regarding the purity of the source gases.

The synthetic methane obtained in this way can either be held in a gas storage facility and converted into electricity with a CHP unit as required, or can be injected directly into the natural gas grid.

Linking the power and natural gas grids

Power thus becomes the primary energy and can be used nationwide to generate heat, or can be converted back to electricity as required, via combined heat and power stations. This link between the electricity grid and natural gas grids is an important condition for the successful transition from conventional to renewable fuels.

Excess power is converted into methane using electrolysis and CO2. The methane can be transported and stored in the gas grid, and can be converted into power as required.




Thomas Heller, MicrobEnergy GmbH Bayernwerk 8 D-92421 Schwandorf, Germany

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