VERBUND has started construction on a pilot plant at the thermal power plant site in Mellach, Austria. The plant will be able to operate both as an electrolyser and as a fuel cell.

Graz University of Technology and Sunfire both evaluate the use of climate-neutral hydrogen in power plant operation as a substitute for natural gas.

With an electrical output of 838 megawatts the Mellach gas-fired power plant is the most powerful plant in Austria. In its use for superregional grid support, it contributes significantly to the electricity supply security throughout Austria. The two gas turbines are currently operated with natural gas.

As part of the recently launched “Hotflex” research project, energy supplier VERBUND will test the partial substitution of natural gas with hydrogen produced in a climate-neutral way in an industrial power plant operation for the first time. 

The starting point for the new plant is the expansion of renewable energies all over Europe. Currently, the main type of large-scale storage for wind and solar power is pumped-storage.

With the “Hotflex” pilot plant, excess wind and solar power can be taken from the grid and converted into hydrogen by high-temperature electrolysis. This “green” hydrogen will then be mixed with natural gas to drive the two gas turbines in a more climate-neutral manner.

The hydrogen is to be produced directly at the power plant site by high-temperature electrolysis with a production capacity of 40Nm3/h.

A special feature of the Mellach pilot plant, whose components are manufactured by the cleantech company Sunfire in Dresden, is that it can operate in reverse mode as a fuel cell.

VERBUND will test the fuel cell operating mode primarily as a possibility for self or emergency power supply of its power plant.