Stiesdal Hydrogen

Stiesdal Hydrogen delivers electrolyzers and a proven concept for fully integrated, turnkey hydrogen plants combining maximum efficiency with scalability. Our standardized, pressurized alkaline Electrolyzer and Hydrogen Block system enables rapid deployment and reliable, cost-competitive production of green hydrogen.

Plant concept targeting CAPEX below €1,000/kW

Turnkey hydrogen plants, installed within months, delivering proven dynamic performance.

A new industrial chapter for hydrogen

Stiesdal Hydrogen redefines green hydrogen with a modular, industrialized electrolyzer and plant concept shaped by decades of innovation in the renewables industry.

Traditional hydrogen production plants are custom-built chemical factories. The Stiesdal Electrolyzer and Hydrogen Block concept is radically different. It is a standardized, scalable hydrogen plant that applies the same approach to site works as wind and solar farms: maximum modularization and prefabrication – minimum work on site – simple infrastructure with no need for buildings, delivering major cost reductions on balance of plant and civil works.

The result is a hydrogen plant concept that can be installed within months, operates flexibly with intermittent power, and delivers green hydrogen at globally competitive cost.

Key differentiators:

Industrialized and modular

Next-generation alkaline electrolyzer and hydrogen plant concept, industrialized throughout from the electrolyzer units to the balance of plant and installation process.

Each electrolyzer is a self-contained unit, built from components supplied by leading European Tier-1 partners, and delivered on two standard trucks, ready for rapid deployment.

The Hydrogen Block plant layout is modular by design, focused on simplicity and functional efficiency. No buildings are required, and all support systems (water treatment, nitrogen supply, gas cleaning, etc.) are modular, offering built-in redundancy. Capacity can be scaled seamlessly by adding more standard modules as demand grows.

The basic module is a 3.1 MW electrolyzer unit. Projects can start small – for example, 12,4 MW with four units – and expand stepwise to 25 MW, 50 MW, or beyond.
Dynamic by design

The electrolyzer is optimised for intermittent operation with minimal degradation over thousands of start-stop cycles.

This dynamic capability enables hydrogen plants to act as demand-side participants in electricity markets and ensures smooth integration with variable renewable electricity sources.

The system cold-start time is under five minutes. It ramps at 1% per second, operates across a wide load range, and shuts down instantly.
Efficient and cost-optimized

Electrodes and support systems are designed for high efficiency throughout, and the electrolyzer stack features internal electrode cooling to ensure uniform temperature and minimize electrical losses.

The stack is integrated into a pressure vessel, providing outdoor protection while delivering hydrogen at up to 35 bars without compression losses, reducing downstream CAPEX and OPEX.

All modules are built from components already in mass production, minimizing cost and enabling rapid production scale-up.
Simple interfaces
A Stiesdal Hydrogen Block has a minimal set of interfaces at the fence line:

Input:
- Medium voltage AC power supply – 33 kV or equivalent
- Process water at tap water quality
- SCADA control signal
Output:
- Hydrogen at up to 99.999% purity
- SCADA monitoring data
Proven control and power systems from the wind industry ensure full grid-code compliance with no need for supplementary STATCOMs, harmonic filters, capacitors, or reactors.

Three modular Stiesdal 3.1 MW electrolyzer units in operation at the Glansager site i Southern Denmark.

Inside the fence: what a Stiesdal Hydrogen Block includes

A Stiesdal Hydrogen Block plant is delivered as a complete turnkey facility. Each Block integrates electrolyzer units, MV transformers, auxiliary systems, and balance of plant and civil works within a clearly defined scope.

All systems required to produce, condition, and deliver green hydrogen are included within the fence line, minimizing interfaces and turning project execution into a dependable package for developers and investors.

Competitive system cost

The Hydrogen Block concept targets a system CAPEX below €1,000/kW for standard scope. This is achieved through standardized units, industrialized installation, and a clearly defined project scope. Developers benefit from a predictable, transparent cost structure that supports credible project development and enables large-scale rollout.

CAPEX depends on site location, project size, scope, grid capacity, utilities, and project-specific requirements beyond the standard plant design.

Learn more about our electrolyzer technology →

From deployment to operation in months

The video below illustrates the build-out of a 16-unit Hydrogen Block, 50 MW, from foundations to a fully operating plant. The sequence highlights how a modular approach cuts complexity, accelerates commissioning, and turns what used to be a multi-year process into a matter of months.