Alquion takes final investment decision on 500 kWFlexolyser
Budel, Schiedam and Eindhoven, 5 October 2026
Alquion has taken the final investment decision (FID) on a 500 kW Flexolyser demonstration project at Nyrstar's industrial site in Budel. The project scales up the 50 kW pilot at Eindhoven University of Technology to a commercial-scale prototype at an industrial customer, the final step towards a first-of-a-kind (FOAK) stack. Total costs for building and operating the project are EUR 10 million, of which EUR 3.7 million is supported by a DEI+grant to the consortium partners. The plant will start operating in summer 2027 and run until 2029. Its hydrogen will be used in Nyrstar's water treatmentplant, reducing nitrogen deposition in the surrounding Natura 2000 areas.
Scaling up from pilot to demonstration
The 500 kW Flexolyser demonstration plant in Budel builds on Alquion's 50 kW pilot at Eindhoven University of Technology, where the cell design was tested for functionality, safety and performance (TRL6). The demonstration is the next step in Alquion's product roadmap. It is a full-scale 'short stack' test at an industrial customer that validates the design for a full 5-7 MW FOAK stack (TRL8). Alquion is in discussions about this with several parties in the chemical industry and offshore wind.
The Flexolyser technology builds on development work by Battolyser Systems and VDL Hydrogen Systems since 2021, continued under the name Alquion following their merger in March 2026. The technology is based on more than 200,000 test hours in Alquion's laboratories and at test set-ups at RWE in Eemshaven and Eindhoven University of Technology.
Flexibility without safety risks or degradation
In Budel, Alquion will demonstrate something no industrial electrolyser can do yet. It will produce hydrogen fully flexibly for an industrial application, reliably and without degradation. The Flexolyser will be switched on and off more than 20 times a day, with standstill periods of over 8 hours, without compromising on safety, lifetime or efficiency. This flexibility is key to competitive production of green hydrogen (RFNBO) in the Netherlands and to the further roll-out of solar and wind power.
Green hydrogen for water treatment, less grey hydrogen andnitrogen
The hydrogen produced will feed anaerobic bacteria in Nyrstar Budel's water treatment plant. As a result, Nyrstar needsto produce less grey hydrogen with its own steam methane reformer (SMR), which emits 9 kg of CO2 per kg of hydrogen as well as nitrogen that is deposited in the surrounding Natura 2000 areas. The Flexolyser demonstration project reduces these nitrogen emissions. In all of Nyrstar Budel's future scenarios, the water treatment plant will remain operational at least until the end of the projectin 2029.
Subject to continued operations at the Budel site and a successful demonstration, Nyrstar is considering replacing itsentire SMR with Flexolyser capacity, followed by large-scale deployment to integrate renewable energy at the Budel site.
"This is an important step in the product development of the Flexolyser. It is the first electrolyser for industrial applications that can follow the volatility of electricity prices, and with Nyrstar we are demonstrating this at commercial scale in an industrial complex."
Mattijs Slee, CEO Alquion
A new business model through flexibility
Because the Flexolyser can be switched fully on and off without loss of performance, a customer does not need to run continuously at a minimum of 20-40% capacity, as is the case with conventional electrolysers. The Flexolyser follows the supply and price of electricity, producing hydrogen when renewable power is cheap and switching off when it is not. This lowers hydrogen production costs, generates additional revenue through trading on the electricity market and helps relieve grid congestion. For a 100 MW Flexolyser on the Maasvlakte, Alquion calculated that this can improve the return (IRR) of green hydrogen projects by 40-80% compared with the best-performing electrolysers on the market today. Flexibility is the value proposition, while costs and performance are on par with the best-performing alkaline electrolysers on the market.
Thanks to its flexible operation, the Flexolyser is ideally suited to integrating offshore wind without adding to grid congestion and with ever less subsidy (Contract for Difference). With offshore wind and the Flexolyser, the Netherlands is building its own value chain for renewable hydrogen, in line with its national obligations under REDIII. FID for the FOAK stack is planned for 2028, enabling Alquion to bring standard 25-50 MW modules to market to serve GW-scale projects.
"The Flexolyser is an innovative solution that fits well with electricity trading, an area where Nyrstar isalready strong. We look forward to applying this technology at scale at our site in Budel."
Ruben Boeree, General Manager Nyrstar Budel
Alquion and Nyrstar, together with their consortium partners, thank GroenvermogenNL and RVO for their contribution and support in making this demonstration project possible.
About Alquion
Alquion B.V. (Schiedam, Eindhoven) is a cleantech scale-up that develops and commercialises the Flexolyser®, a fully flexible alkaline electrolyser for industrial applications.
About Nyrstar Budel
Nyrstar Budel is part of Nyrstar and one of the world's largest zinc smelters, located in Budel-Dorplein.
Press contact
Rene de Milliano, +31 (0)6 25 45 71 46,r.de.milliano@alquion.com
