ITM Power is pleased to announce that, with its partners Mainova Aktiengesellschaft and NRM Netzdienste Rhein-Main GmbH, the company has injected hydrogen into the German gas distribution network.

The ITM Power rapid response electrolyser plant has been delivered and commissioned ahead of schedule and the compliance and permitting work has been completed to enable the incorporation of hydrogen via the compliant mixing plant.

According to an announcement made by the Thüga Group, “During the current commissioning phase of the Thüga Group’s power-to-gas demonstration plant, the system injected the first ever electrolytically generated hydrogen into the Frankfurt am Main gas distribution network. This represents the first ever plant to convert electricity into hydrogen and subsequently inject the hydrogen into the German gas distribution network.”

Michael Riechel, Member of the Board of Thüga AG said, “The system worked as planned, so much so that we will go into trial operation in the very near future ahead of final commissioning at the start of 2014.”

By the end of 2016, the partners will have gained experience of how the system works under real-world conditions. The operational phase will be accompanied by scientific partners, whose involvement is being funded by the Hessian Ministry for the Environment, Energy, Agriculture and Consumer Protection.

H2 injection without compression

The core of the system is an ITM Power proton exchange membrane (PEM) electrolyser. The electrolyser converts electrical energy into chemical energy, which in turn facilitates the storage of electricity. A gas mixing plant ensures that the proportion of hydrogen in the natural gas stream does not exceed two per cent by volume, the technically permissible maximum value when a natural gas filling station is situated in the local distribution network. The electrolyser supplies the hydrogen-methane mixture at the same pressure as the gas distribution network, namely 3.5 bar.

“We were thus able to avoid using a compressor and save costs,” said Riechel. The plant is located on the premises of Mainova AG in Schielestraße in Frankfurt am Main. The project partners decided to deploy a PEM system, as this technology, in comparison with alkaline systems, uses water rather than a potassium hydroxide solution, and is therefore more environmentally friendly. In addition, the system can respond more quickly to changes in the electrical load.

A further advantage is the unit’s compact design (2.45m high, 6m long, 3.30m wide, weighing 10 tonnes). The power consumption of the electrolyser is 315 kilowatts. It produces about 60 cubic meters per hour of hydrogen and thus in one hour can feed 3,000 cubic meters of hydrogen- enriched natural gas into the network.

A total of 13 companies of the Thüga have combined their collective know-how and capital in a project platform to invest jointly in the development of power-to-gas storage technology. The focus is on testing the feasibility of power-to-gas technology. The companies are confident that in the long-term, this offers the greatest potential for storing excess renewable energy. The plant converts electricity into hydrogen and then stores this in the gas distribution network. Overall, the partners will invest more than €1.5m. The project is financially supported by the Hessian Ministry for the Environment, Energy, Agriculture and Consumer Protection. Following the first phase of this project, the partners will consider a second project, in which hydrogen will be generated and combined with carbon dioxide to form synthetic methane to be directly injected and stored in the natural gas grid.