Rijeka refinery, Croatia's largest fuels plant on the northern Adriatic, is hosting construction of the country's first green hydrogen production facility, Total Croatia reported.

The project places electrolysis capacity directly inside an operating refining complex — a siting choice that matters for downstream readers. Rijeka, run by Zagreb-based INA Group, processes crude into motor fuels and petrochemical feedstocks for the Croatian and regional markets. Co-locating a green hydrogen unit at the refinery allows the operator to displace a portion of the grey hydrogen the plant consumes in hydrotreating and desulphurisation service, where hydrogen demand is structural rather than speculative.

The designation "first" carries weight here. Croatia has had no green hydrogen production to date, according to the report, so the Rijeka unit establishes the country's initial electrolyser footprint. No commissioning date was disclosed in the reporting available.

The Rijeka build follows a pattern now visible across European refining: operators facing tightening product specifications and decarbonisation pressure are adding renewable-powered electrolysis at existing sites rather than building standalone hydrogen plants. Refinery gates offer grid connections, water systems, storage, and — critically — captive hydrogen demand that de-risks the offtake side of the project economics.

What remains unconfirmed in the source material: the electrolyser's nameplate capacity in megawatts, its expected annual hydrogen output in tonnes, the power purchase arrangements backing the "green" classification, and the capital cost. Those figures will determine whether the unit is a demonstration-scale installation or a meaningful share of Rijeka's hydrogen balance.

INA has been repositioning Rijeka through its long-running modernisation programme, and the hydrogen plant extends that investment logic into energy-transition infrastructure at the same site.

The watch items: commissioning timing, disclosed electrolyser capacity, and confirmation of renewable power sourcing — the regulatory test that separates genuinely green hydrogen from grid-fed production wearing the label.