Construction has begun on a model new building project in Esslingen, southern Germany, which aims to demonstrate that CO2-neutral neighbourhood power supply is within reach. When it is completed in 2023, the site of a former goods yard station set across 100,000 sqm will be home to 500 apartments, offices and commercial spaces, as well as a facility for the Esslingen University of Applied Sciences.

The engine which will power the ‘Neue Weststadt’ district is an electrolyser, which will be housed in a subterranean energy centre. It will draw energy from solar panels on the rooves and from renewable sources to produce green hydrogen. The power-to-gas solution will be built by Green Hydrogen Esslingen, a joint venture between the green electricity provider Polarstern, the Esslingen municipal utility company and Prof. Manfred Norbert Fisch (from the Steinbeis Innovation Centre EGS in Stuttgart), with funding from BMWi.

"With this concept, we have brought electrolysis into the city," explains Tobias Nusser from the Steinbeis EGS in the online journal Building the Energy Transition. "There are already a number of plants in Germany in the one-megawatt range, but they are all on greenfield sites, close to the producers but usually far away from where the energy is needed in the cities.”

By locating the electrolyser on site, any waste heat which is generated in the process can be used to heat the living spaces. It is estimated that 400kg of green hydrogen will be produced a day, which could be fed into filling stations for fuel cell vehicles in the future, while any excess will be fed back into the gas network.

The electrolyser has to go through a rigorous planning approval process but should be green-lit in April 2020. Nusser anticipates the electrolyser will run for about 4,000–5,000 hours per year and will produce hydrogen around 50% of the time – although they are aiming for 90%.