Sponsored Article
02 February 2026
Green hydrogen production demands uncompromising safety. Operating at high pressure with aggressive electrolytes and explosive gases, Nordex Electrolyzers relies on SIL-certified, ATEX-approved measurement technology from VEGA to ensure reliable, safe operation of its alkaline pressurised electrolysers.
The production of green hydrogen places extreme demands on plant safety and measurement technology. High pressures, elevated temperatures, aggressive electrolytes and explosive gases create a process environment where functional safety and hazardous-area compliance are critical.
In Spain, Nordex Electrolyzers is developing alkaline pressurised electrolysers designed to operate with fluctuating wind power. To ensure safe, reliable operation under these demanding conditions, the company relies on measurement technology from VEGA.
Electrolysis under pressure
Green hydrogen production via alkaline pressure electrolysis involves operating pressures of up to 27 bar and temperatures of around 95°C, using caustic potassium hydroxide (KOH) as the electrolyte. Hydrogen and oxygen are generated as reactive gases, while frequent pressure changes occur during dynamic operation.
These conditions place high demands on instrumentation. Sensors must deliver precise measurement values while meeting the requirements for functional safety (SIL) and explosion protection (ATEX). At the same time, they must remain reliable in aggressive media and integrate easily into the overall plant design.
Nordex Electrolyzers’ 500 kW prototype plant has been designed specifically for real-life operation with fluctuating renewable energy, requiring stable and dependable measurement across the entire system.
Safety-critical measurement across the plant
VEGA sensors are used throughout the electrolyser to measure pressure and level in hydrogen, oxygen and electrolyte circuits, as well as in separators, filters and peripheral systems.
– VEGAFLEX 81 guided radar sensors measure levels in separators and gas scrubbers, delivering reliable results even with phase changes and gas bubbles in the liquid.
– VEGABAR 82, featuring the ceramic CERTEC® measuring cell, is used for pressure measurement in hydrogen, oxygen, electrolyte, deionised water and cooling circuits. The diffusion-tight measuring cell is resistant to chemicals and designed to withstand frequent pressure changes.
– VEGABAR 29 is installed before and after electrolyte filters to monitor pressure and filtration performance. Its metallic measuring cell is suitable for permanently high pressures.
All sensors are certified according to IEC 61508 and approved for use in hazardous areas with ATEX and IECEx certifications.
Safety without compromise
“Safety without compromise is crucial when selecting our plant equipment,” explains Javier Fernandez de Manzanos, Technical Director at Nordex Electrolyzers. “VEGA convinced us not only in terms of reliability, but also as a globally recognised brand. Technical support was also important in the decision-making process.”
In addition to certification, features such as oil-free ceramic measuring cells, gold-rhodium coatings and diagnostic functions for preventive maintenance contribute to safe and stable operation. Digital options including Bluetooth and IO-Link support commissioning and parameter adjustment.
Proven reliability in operation
The sensors were installed in a modular skid system and commissioned by the Nordex Electrolyzers team, supported by VEGA experts. The system has now been in operation for over a year, delivering reliable measurement data despite aggressive media, fluctuating temperatures and high process pressures.
According to Nordex Electrolyzers, the stable measurement data has supported optimisation of plant efficiency and helped maintain a high level of gas purity – even during partial-load operation.
Supporting safe hydrogen production
The experience gained from the prototype is being incorporated into further development, with the aim of safe and economical hydrogen production under demanding process conditions. Precise and reliable measurement technology plays a decisive role in ensuring functional safety and dependable operation in hazardous areas.
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