A modular approach to hydrogen electrolyser technology could help the sector scale rapidly, according to the developers of a green hydrogen project in Denmark.

The GreenHyScale project will demonstrate 100MW of green hydrogen based on a modular alkaline electrolyser platform delivered by Green Hydrogen Systems.

A 6MW module was demonstrated as the first step in the project, which is now operating at 24MW, and will eventually lead to an electrolysis plant of at least 100MW size.

“Scaling is the key word—we are scaling a market and you cannot scale up in one jump,” says Niels-Arne Baden CEO of Green Energy Systems, speaking on a webinar. “We believe in a modular approach not huge custom-built onsite systems.”

The firm can scale up to GW-level projects using this approach.

“We believe in a modular approach not huge custom built onsite systems,” Baden, Green Energy Systems

Modular units are easier to ramp up and down than a large electrolyser, helping the facility cope with the intermittency of the renewable generation that powers it.

We have limited number of wind hours per year,” says Baden. “So another thing we can do with modules is we can ramp up and down very fast.”

The facility can go from operating 16pc of one 6MW module to the full 24MW in less than five seconds.

“That extreme flexibility allows us to power up when the wind picks up,” he says.

The plant will generate green hydrogen from directly connected renewables in combination with certified green electricity from a grid connection. Waste heat will be used on-site and in connection with district heating.

Modular electrolysers are often used for on-site hydrogen production at industrial sites, manufacturing plants and hydrogen fuelling stations.

Many small modular stacks make a significantly more flexible electrolyser plant than a large stack with a single rectifier, regardless of stack technology, according to a report released by the intergovernmental organisation International Renewable Energy Agency (Irena) in 2020.

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Author: Tom Young