Far beneath Iceland’s rugged surface lies an energy source that could transform the global green transition: geothermal heat. Researchers in Iceland and Norway are now racing to multiply the power of geothermal wells by fivefold—or more—by tapping “supercritical water,” an extreme state of water occurring at over 374 °C and pressures more than 200 times that of the Earth’s surface.
Iceland already leads the world in geothermal use: over 99% of its electricity is renewable, with nearly half of its heating demand met by geothermal energy alone. Yet globally, geothermal still accounts for under 3% of electricity generation, mainly because traditional wells can’t reach the deeper, hotter zones efficiently enough to be profitable.
The Iceland Deep Drilling Project (IDDP), supported by partners like SINTEF and Equinor, has made significant advances and faced dramatic setbacks. The first two experimental wells hit promising high temperatures but failed structurally because the outer well casings could not withstand the combined effects of extreme heat, corrosive fluids, and intense pressures. The latest phase, the EU-funded COMPASS project, aims to solve this by developing robust, flexible, corrosion-resistant casing systems and advanced simulation tools.
One innovation is a laser-applied protective coating on the casing, designed to withstand the harshest underground environments. Another is SINTEF’s “Casinteg” simulation tool, which models the immense stresses and chemical reactions inside the well, enabling engineers to design stronger, longer-lasting structures at lower cost.
If successful, this new generation of deep geothermal wells could produce five to ten times more electricity than conventional wells—potentially enough to elevate geothermal’s share of global electricity to over 8% by 2050, while cutting CO₂ emissions by more than two gigatonnes annually.
Beyond power generation, researchers see geothermal wells playing a future role in carbon storage, hydrogen production, and thermal energy storage, extending each well’s lifespan and sustainability.
As the COMPASS team prepares to drill its third experimental super-well, Iceland remains a living laboratory for how deep-earth heat might power a cleaner energy future—one that’s always on, nearly CO₂-free, and locally sourced.
Closest global competitors:
While Iceland’s ambitious geothermal projects push the boundaries of deep drilling and supercritical energy extraction, several major players worldwide are advancing geothermal technologies in parallel. Companies like Ormat Technologiesand Enel Green Power are leaders in commercial geothermal power plants, operating significant facilities in the United States, Italy, Kenya, and Indonesia. Calpine Corporation runs The Geysers, the largest geothermal complex in North America. Kenya Electricity Generating Company (KenGen) is expanding Africa’s geothermal footprint in the Rift Valley. Chevron Geothermal and Pertamina Geothermal Energy continue to develop Indonesia’s vast underground reserves. In the Asia-Pacific region, Star Energy Geothermal and Contact Energy contribute to robust geothermal grids in Indonesia and New Zealand, respectively. Technology providers such as Toshiba Energy Systems & Solutions supply high-efficiency turbines tailored for extreme geothermal conditions. Together, these companies and technology innovators represent Iceland’s closest global competitors in the quest to unleash geothermal’s massive untapped potential and redefine renewable energy’s role worldwide.
Photo: Geothermal Research
