WindGas for the Energy Transition with Uniper’s Power-to-Gas Plant

Horizon2020 project STORE&GO helps explore innovative storage technologies.

For a successful energy transition, we will need large scale energy storage in order to ensure the security of supply. Uniper therefore operates the pilot plant WindGas Falkenhagen, Germany, where we have been demonstrating how renewable electricity can be used for the production of hydrogen by electrolysis, since August 2013. This “green hydrogen” is then fed into the natural gas network effectively storing the excess power produced from renewable electricity generation. The Falkenhagen power-to-gas plant has an output of 2 MW and generates 360 cubic meters of hydrogen per hour. Falkenhagen in Brandenburg is an ideal location due to its high wind generating capacity and the well-developed power and gas infrastructure already in place.

In May 2018 the power-to-gas site was expanded by a methanation plant to offer even more possibilities of storage for renewable energies. The new methanation plant provides for the generation of “green” methane. In this second stage, hydrogen from regenerative energy sources is converted into methane (CH₄), i.e. synthetic natural gas (SNG), using CO₂ from a bio-ethanol plant. This constitutes an important contribution to the success of the energy transition, because green methane in contrast to green hydrogen can be used in a wider variety of ways. It can be made available to a variety of markets, such as the manufacturing sector, the electricity and heating market as well as the mobility sector. Moreover, it provides for unrestricted use of the natural gas infrastructure, including for transport and storage. This stored energy is then available as backup whenever there is an insufficient supply of solar and wind power.

The new methanation plant was built right next to the PtG pilot plant and consists of several components. A prototype honeycomb catalytic reactor for methanation is installed and is being tested during the project. The methanation plant produces up to 57 m³/h of SNG (at normal pressure and temperature), which equates to an output of 600 kWh/h. By comparison: The same amount of energy could heat a 50-m² apartment for a month. Moreover, the heat generated by the process is used by a nearby veneer plant.

WindGas Falkenhagen is part of the Horizon 2020 project STORE&GO, which aims to bring the technology to a level to be integrated in the daily operation of European energy grids. Uniper Energy Storage GmbH builds and operates the new plant together with thyssenkrupp Industrial Solutions AG, the research centre of the DVGW (German Association for Gas and Water) and the Karlsruhe Institute of Technology (KIT). thyssenkrupp and KIT designed the reactors for methanation and KIT is also providing scientific assistance to the project.