ELES, Plinovodi and Japan’s Yokogawa Electric signed a memorandum on Sept. 10 to develop a Slovenian hydrogen ecosystem and an initial demonstration project connecting electricity and gas transmission infrastructure. The work will examine a hydrogen plant designed to interface with both networks. It will also cover the digital systems needed to coordinate operation across the two infrastructure types.
Yokogawa will provide process-control and digital expertise, while ELES and Plinovodi will supply electricity and gas-system operating capabilities. The partners said the focus of the project is less on hydrogen as a fuel than on the operating flexibility of the electrolyser used to produce it. An electrolyser is described as a large electricity consumer whose output can be varied within technical and commercial limits in response to power-system conditions.
Electrolyser flexibility as a power-system operating lever
The memorandum describes how hydrogen production can increase when renewable electricity is abundant. It also states that consumption can be reduced when the electricity system tightens. The energy is not eliminated; it is shifted into another carrier that can be stored, transported or consumed later.
The project material highlights that hydrogen can transfer energy value not only between hours but also between infrastructure systems. It frames this as a characteristic that differs from conventional industrial loads. The demonstration is intended to test how electricity and gas assets could be coordinated rather than operated independently with only connection at the electrolyser.
Coordinated operation using digital control and optimisation
ELES and Plinovodi said they want to orchestrate electricity and gas infrastructure as one operating system, instead of running them separately. The partners identified digital solutions for coordinated operation as part of the planned demonstration. This includes forecasting and control software positioned alongside electrolyser operation.
An optimisation platform is described as comparing electricity prices, system balancing requirements, renewable availability, hydrogen-storage levels, gas-network conditions and downstream hydrogen demand before determining plant operation. The dispatch decision is described as extending beyond whether a hydrogen selling price exceeds an electricity cost for the same day. It could incorporate the value of flexibility supplied to the electricity system.
The memorandum outlines multiple potential revenue layers tied to different functions of the plant. Hydrogen sales are identified as underlying commodity revenue, while electricity-market optimisation could lower production costs by concentrating consumption in cheaper hours. Flexible operation could potentially reduce imbalance exposure or provide demand-side system services where market rules allow.
It also notes that longer-duration hydrogen storage could move energy across periods that batteries or ordinary demand response cannot cover economically. The partners did not announce a commercial operating model, and they said not all revenue streams are available today. The first phase is described as a feasibility study covering technical, operational and commercial pathways.
Renewables surplus, feedstock use and investment trade-offs
The project material links higher renewable penetration in Slovenia to increased need for flexible electricity demand. It says electrolysers could operate during periods when renewable generation exceeds immediate electricity demand or when moving additional power through the network becomes difficult. Instead of curtailing generation, part of that electricity could be converted into hydrogen.
The memorandum distinguishes this approach from operating a hydrogen plant at maximum utilisation continuously. It states that high utilisation lowers unit costs of expensive electrolysis equipment, while flexible operation enables consumption of cheaper electricity and provides greater value to the power system. It describes an optimum between these two operating approaches.
The study is framed around an investment question for developers: whether to maximise annual operating hours or maximise value per operating hour. ELES’s involvement is presented as indicating Slovenia intends to examine the second model seriously within the feasibility work.
Gas storage horizon and regional hydrogen corridors
Plinovodi’s role adds an element related to longer-term storage compared with typical power-sector flexibility timeframes. Electricity flexibility is described as usually discussed over minutes or hours through balancing markets and batteries. Gas infrastructure is described as able to store and transport energy over much longer periods.
The memorandum states that hydrogen produced during favourable electricity conditions could move value from the power sector into industrial demand, transport or potentially future hydrogen-network infrastructure . It also says Plinovodi has been working on Slovenia’s connection to emerging European hydrogen corridors, extending relevance beyond domestic consumption . If hydrogen networks develop across Central Europe, Slovenian electrolysis would not depend exclusively on local buyers.
The partners say exportable hydrogen demand could create an additional buyer for low-value electricity within the broader regional context. This would potentially provide the electricity system with access to a larger flexible demand sink .
Mobile backup units for critical infrastructure
The memorandum also covers hydrogen-based mobile backup units for critical electricity infrastructure. The units are described as designed so that the same equipment could additionally function as fast-charging infrastructure for electric vehicles . ELES and its partners said they are examining hydrogen within resilience planning by supplying backup power when conventional infrastructure is disrupted.
The partners describe using the equipment commercially for other purposes when it is not needed for emergencies . They contrast this with conventional standby generation, noting backup equipment typically earns little outside rare emergency events . A multifunctional unit capable of providing transport charging or other energy services is described as having potential value during normal operation as well.
Feasibility focus on cost, market participation and measurement
The memorandum identifies cost as the biggest challenge for low-carbon hydrogen production via electrolysis. It states that producing such hydrogen requires substantial equipment investment and large quantities of electricity . Flexible operation can lower electricity costs, but running an electrolyser fewer hours can increase capital cost allocated per kilogram of hydrogen produced.
Digital optimisation is described as not being able to rescue an inherently uneconomic project by itself . The feasibility work will assess whether combining several uses—hydrogen production, electricity flexibility, infrastructure resilience and potentially mobility—can generate sufficient revenue to justify investment . It will also need rules governing how the electrolyser participates in electricity markets and how hydrogen entering future gas infrastructure is measured, certified and valued .
The partners describe the Slovenian project as still far from a commercial hydrogen market while testing whether an electrolyser can operate as a dispatchable interface between two energy systems . They indicate that if this model becomes economic, regional value may depend on when the electrolyser switches on and off as well as on total tonnes produced .
