Siemens will build one of the world’s largest green hydrogen plants in southern Germany, taking power from wind and solar to produce H2 and recycling the by-products from the process for local industry in what’s claimed to be the first facility of its kind to achieve “maximum energy efficiency”.

The Siemens Smart Infrastructure unit and hydrogen specialist WUN H2 will build the plant in Wunsiedel, Bavaria, with a first-phase plan to take power from 6MW of renewable capacity and output of 900 tonnes of hydrogen after commissioning in 2021.

That H2 production is planned to grow to 2,000 tonnes annually, said Siemens, with the green hydrogen stored for shipment to users in northern Bavaria and the Czech republic. The plant may also add its own hydrogen refuelling station for heavy vehicles at the site, where a Siemens battery storage facility is already in operation.

Industrial users near the Wunsiedel project – which will use proton-exchange membrane (PEM) electrolysis to produce its hydrogen – will use the heat and oxygen generated as by-products of the process in their own operations.

Siemens claimed that makes the plan “unique” and able to achieve “maximum energy efficiency because all element flows will be utilised”.

The German industrial giant claimed the project will serve as “a model for all of Germany. It will convert the renewable energy available in this region from photovoltaics and wind power, into storable hydrogen, making it available for applications in mobility and industry.

“This is especially useful when, on sunny and windy days, more energy from renewable sources is produced than needed.”

The 900-tonne initial production target makes Wunsiedel one of the world’s largest green hydrogen plants planned to enter service in the near future, although mega-scale projects for the longer-term aim to be churning out the key energy transition fuel at the rate of hundreds of megawatts a day.

The Institute for Energy Economics and Financial Analysis (IEEFA) recently warned that the world could face a drought of green hydrogen by 2030, when it expects demand to hit 8.7 million tonnes

The inability of green hydrogen to scale quickly enough is a key argument used by those proposing the use of blue hydrogen from abated fossil fuels as a major early plank of the energy transition.

Siemens also gives no indication of cost of the green H2 produced, with competitiveness against blue and unabated 'grey' hydrogen also regularly cited as an obstacle to early renewable hydrogen uptake.

Germany this year earmarked €9bn ($10.2bn) in fresh support for hydrogen, pledging to put green hydrogen at the heart of its energy transition plans but since admitting it may have to look as far afield as Australia and, reportedly, Africa to satisfy its massive H2 needs.