Syntholene Energy produces first 500kg of green hydrogen at world’s first geothermally integrated SOEC plant in Iceland
Canadian cleantech company Syntholene Energy Corp. has produced the first 500 kilograms of green electrolytic hydrogen at its geothermally integrated Solid Oxide Electrolyser Cell demonstration facility in Húsavík, Iceland, declaring it the world’s first fully integrated deployment of high-temperature electrolysis coupled directly with a live geothermal heat source.
The Newsfile announcement confirmed that the hydrogen was produced at above 99.9% purity, with the SOEC system consuming approximately 33.5 kWh per kilogram of hydrogen at stack level and 37.8–40.0 kWh/kg at system level, which the company says demonstrates measurable efficiency gains from the geothermal thermal integration compared with standard high-temperature electrolysis.
The facility was constructed in just 69 days at the historic Húsavík Power Station — six months ahead of the original schedule and under budget — and uses geothermal heat to pre-warm the SOEC stacks, substantially reducing the electrical energy required for the electrolysis process. Syntholene’s system incorporates SolydEra G8X SOEC stacks delivered by Danish electrolyser company Dynelectro, which also supplied a 250 kW dynamic electrolyser unit to the site.
The company has commenced continuous operational testing, evaluating stack performance, system efficiency, thermal integration, reliability and operating economics under sustained conditions. Independently validated full-effects performance data are targeted for publication in the fourth quarter of 2026.
Chief Executive Dan Sutton said the results demonstrate that the facility is operating as designed and that the thermal coupling between the geothermal source and the SOEC system is performing in line with expectations, marking what he called a critical step toward the company’s goal of demonstrating low-cost hydrogen as the principal feedstock for synthetic sustainable aviation fuel production.
