Syntholene Energy Corp. has completed Phase One effects testing at its geothermally-integrated Solid Oxide Electrolyzer Cell demonstration facility in Húsavík, Iceland, and initiated high-power operations for Phase Two.

The initial testing phase ran the integrated system over an extended period, gathering operational data across the Solid Oxide Electrolyzer Cell, proprietary Thermal Coupling Heat Exchanger, and balance-of-plant equipment.

Syntholene completed construction of the Húsavík facility in June 2026. The current Phase Two program is operating at or near the plant's full available power capacity to evaluate electrical efficiency, hydrogen production, and thermal integration under higher-load conditions.

“Phase One successfully operated the integrated system for an extended period, and generated novel real-world data required to characterize its performance,” stated Dan Sutton, Chief Executive Officer of Syntholene. “With that phase complete, our focus now shifts to high-power operations. Phase Two is intended to characterize the system at higher operating loads and provide a second operating dataset from which we can evaluate the wider capability of our thermal-hybrid architecture.”

“We are seeking to understand if Syntholene's geothermal integration can reduce or eliminate the need for battery electric and/or hydrogen storage, how effectively geothermal heat can displace electrical energy in hydrogen production, and what those results could ultimately mean for the economics of hydrogen and synthetic fuels,” stated Sutton. “High-power operations are an important next step in establishing that operating envelope.” — Dan Sutton, Chief Executive Officer

The company expects to conclude Phase Two high-power operations in the coming months. Following completion, Syntholene plans to submit the data from both testing phases to an independent third party for formal validation.

Independent technical reviews completed by Kellogg Brown and Root LLC in July 2026 estimated a levelized cost of hydrogen of approximately US$1.75 per kilogram under best-case Iceland geothermal scenarios. The platform supports Syntholene’s broader commercial target of producing synthetic sustainable aviation fuel, for which the company holds a non-binding Expression of Interest from Icelandair covering the potential purchase of 20,000 tonnes annually over 10 years.

Read the full announcement: Syntholene Completes Phase One of Effects Testing at Iceland Demonstration Facility, Advances to High-Power Operations