World-first for Siemens Gamesa as hydrogen flows from island mode-capable turbine

Using a 3-MW turbine connected to a 400-kW electrolyser, Siemens Gamesa plans to produce green hydrogen that project partner Everfuel will distribute. The Brande Hydrogen project is acting as a testbed for large-scale, cost-efficient hydrogen production from wind energy.

Siemens Gamesa senior business analyst innovation and products Henrik Mortensen told OWJ that tests undertaken in late January 2021 saw the turbine at Brande and the electrolyser connected to it produce 1-2 kg of green hydrogen.

Over the next several months, the company will optimise the operation of the system and the distribution system Everfuel will use, with commercial operation scheduled for mid-2021.

The key challenge the Brande Hydrogen project is addressing is the effect fluctuating power input from the wind turbine will have on the electrolyser. The project should provide a clear understanding of the integration of the electrolyser with a variable renewable energy source, and the efficiency of the electrolyser over time.

The electrolysis equipment Siemens Gamesa is using produces hydrogen at 35 bar, which is sufficient to transport the gas to a buffer tank before it is compressed for distribution in trailers operated by Everfuel. The company is using alkaline electrolysis equipment, which meets the requirement of the project for output pressure and variable input.

Mr Mortensen said alkaline electrolysis equipment of the type it is using and polymer electrolyte membrane (PEM) electrolysers both have potential for use in the island-mode concept, although the more recently developed PEM concept is believed to have greater cost-out potential in the long-term. Whichever solution is adopted in future, the ability of the electrolyser to cope with the variable electrical output from a wind turbine is crucial.

The island-mode wind-to-hydrogen concept is mainly applicable to offshore wind turbines. For onshore windfarms, a hydrogen facility such as Brande Hydrogen would, in most cases, still be grid-connected. It could potentially be used to upgrade onshore windfarms to provide asset owners with a second revenue stream, in addition to electrons.

Pure island-mode operation is more likely to be adopted as a newbuild solution offshore and could find applications in far-offshore windfarms for which a conventional grid connection would be technically and financially difficult.

Onshore, Siemens Gamesa expects that the main concept of operations will be a hydrogen facility alongside an existing windfarm, but not necessarily with the turbines in island mode and probably still connected to the grid in many cases.

One of the advantages of an island mode turbine is that it would enable windfarm developers to get around the well-known problem of curtailment. Another is that the electrical losses usually experienced in a turbine and when electricity is transmitted ashore would be eliminated, making the hydrogen-producing turbine more efficient than its electricity-producing counterpart.

As recently highlighted by OWJ, Siemens Gamesa is also working with Siemens Energy on a version of its SG 14-222 DD offshore wind turbine that will produce green hydrogen rather than electricity. They hope to demonstrate wind-to-hydrogen system with three 5-MW containerised electrolysis modules integrated into it, in a representative offshore environment, in 2025/26.

Mr Mortensen said the project at Brande is due to run for two years, and that Siemens Gamesa will continue to work to optimise the process. The project could be expanded and there could be subsequent phases. Recent weeks have also seen Siemens Gamesa incorporate a battery into the system.

Interest in producing green hydrogen from offshore wind is evident in the fast-growing number of projects industry leaders such as Ørsted have embarked on and in national and European level targets for green hydrogen that could be used in mobility, heating and hard-to-abate sectors such as heavy industry and chemicals.