Clean energy firm Syntholene Energy Corp. has completed Phase One testing at its geothermal-powered demonstration facility in Húsavík, Iceland, moving the project into its high-power operational phase as it seeks to lower the cost of green hydrogen and synthetic aviation fuel.
The facility combines a Solid Oxide Electrolyzer Cell (SOEC) system with geothermal heat integration, producing ultra-pure (99.99%) green hydrogen. By leveraging direct geothermal thermal energy alongside electricity, the system aims to reduce the total power required for water electrolysis.
The initial testing phase focused on continuous operations to evaluate the interaction between the SOEC stack, Syntholene’s proprietary heat exchanger, and supporting plant systems. The newly launched Phase Two will push the facility toward its maximum power capacity to measure system stability, electrical efficiency, and output under peak load conditions.
“Phase One operated the integrated system for an extended period and generated the real-world data required to characterize its performance,” said Dan Sutton, Chief Executive Officer of Syntholene. “Phase Two is intended to characterize the system at higher operating loads and evaluate the wider capability of our thermal-hybrid architecture.”
A key objective of the trial is determining whether geothermal heat integration can offset the need for expensive battery storage or large-scale hydrogen buffering, improving the overall economics of zero-emission e-fuels.
Syntholene expects to complete Phase Two operations in the coming months before submitting all operational datasets for independent third-party verification.