It will be possible to produce “green” hydrogen using renewable energy at the same price as CO2-emitting “grey” hydrogen (made from methane) within about five years, according to Siemens.

Green hydrogen — created by splitting water molecules into hydrogen and oxygen inside electrolysers powered by renewable electricity — is often cited as the best option for long-term renewable-energy storage. Green hydrogen can be stored indefinitely and converted back into electricity whenever required using fuel cells (or by burning hydrogen to drive turbines).

This technology would allow excess wind and solar energy to be stored in the summer as molecules — as compressed hydrogen or a derivative such as ammonia — and converted back into electricity in the winter when energy demand is likely to exceed available renewable power.

But as the technology is currently up to four times more expensive than the traditional steam-methane reformation process — which emits 11-12 tonnes of CO2 for every tonne of H2 produced — it is usually talked about as a long-term solution that will not be commercially viable until around 2030.

However, Gabriele Schmiedel, executive vice-president of Siemens’ Hydrogen Solutions business, told the European Utilities Week conference in Vienna that green hydrogen could be produced at the same cost as grey hydrogen by around 2023, when Siemens’ next-generation 100MW-plus range of electrolysers will become commercially available.

“Today’s hydrogen production cost from steam-methane reforming is approximately €2 per kg — plus or minus €0.30,” she told a session on the commercial viability of storage solutions.

“We can match this €2 per kg… for instance with a 100MW plant which generates hydrogen at 35 bar and if you then get the renewable energy for €30/MWh, and you have that in operation for 5,000-6,000 hours per year, then you will come into that comparable pricing level. So it is a viable solution. All that is needed is that there is enough demand from the market... [for electrolysers in] the 10MW, 100MW or even 300MW range. Improving scale is important.”

She also pointed out that if those refineries that currently produce grey hydrogen switch to the water-electrolysis process, they could also receive additional income by using their green hydrogen (and fuel cells) for grid balancing services, further reducing the overall cost of hydrogen production.

At present, hydrogen is mainly used for industrial processes, such as the production of ammonia for fertilisers, but it could also be used in several sectors, including transport (particularly heavy vehicles and shipping) and heating, where it can be injected into the natural-gas network.

Siemens currently offers an electrolysis platform called Silyzer 200, which consists of modular 1.5MW units. It is currently working on its “next paradigm” Silyzer 300 platform, which will offer double-digit-MW electrolysers.

Transition

Green hydrogen ‘commercially viable’ in five years: Siemens