Geothermal energy CCS

Carbfix and ON Power are currently up-scaling the CCS implementation for ON Power's plants - which will result in the world's first near-zero carbon footprint geothermal power plant.

Carbfix operations at ON Power geothermal plants

Carbfix operations at Hellisheiði have considerable scale-up potential, providing a significant impact on emission reduction within Iceland’s geothermal sector. Carbfix received a grant from the EU Innovation Fund to commission a full-scale CO₂ capture and mineral storage facility at Hellisheiði through Project Silverstone. Project Silverstone is a CO₂-optimized capture plant that increases capture efficiency to 95% of the total CO₂ emissions, expected to reduce emissions by 500,000 tons of CO₂ over a 20-year equipment lifetime.

Carbfix's pilot CCS plant, which commenced operations in March 2023 at ON Power's geothermal plant in Nesjavellir, Iceland, successfully initiated the injection of CO₂ and H₂S at the site. There is potential for relocating the pilot plant to various sites for future Carbfix pilot projects. The pilot plant captures all H₂S that flows through it and up to 98% of CO₂. It has an annual capture capacity of 3,000 tons of CO₂ and 1,000 tons of H₂S, which represents approximately 20% of the power plant's annual emissions. The pilot phase will be followed by full-scale CO₂ capture and storage before 2030.

Both Hellisheiði and Nesjavellir Carbfix sites are Geothermal Emission Control (GECO) EU funded research projects. Reykjavík Energy has set itself the goal of neutralizing carbon emissions of its operations by the year 2030 and is a signatory of the climate change declaration, issued by the City of Reykjavik.

Carbfix and the GECO Project

The Geothermal Emission Control (GECO) project aims to make net-zero geothermal energy production standardized through the utilization of Carbfix’s carbon capture and mineralization storage technology. Funded by the European Union’s Horizon 2020 research and innovation program, the GECO project aims to apply the Carbfix method to four demonstration sites across Europe:

1. Basaltic reservoir in Nesjavellir, Iceland,
2. Basaltic reservoir in Hveragerði, Iceland, substituting for Castelnuovo, Italy
3. Volcano-clastic reservoir in Kızıldere, Turkey
4. Sedimentary reservoir in Bochum MULE, Germany.

GECO will implement lessons learned at the first Carbfix demonstration site (Hellisheiði) to the four new field sites, where emissions will be captured for reuse or mineralization storage.

Subsequent monitoring of carbon and sulfur mineralization reactions occurring at the four GECO field sites will enable future predictions on the chemical behavior of a variety of geothermal systems utilizing the Carbfix method. The developed monitoring tools will decrease the cost and risk associated with geothermal energy projects in the future.

The GECO project is led by a consortium of experienced industry members and coordinated by Carbfix-Reykjavík Energy (OR). There are a total of 18 industrial partners spanning Europe and the Middle East. For more information on the consortium partners see here.

Global applications

There is vast potential to apply Carbfix’s CO₂ capture and mineral storage to the global geothermal sector. Worldwide geothermal emission rates of CO₂ and H₂S greenhouse gases have been coupled to sequestration capacities (net CO₂ and H₂S drawdown) for annual emissions of suitable countries, generalized by appropriate rock types and associated geothermal systems. Marieni et al´s. (2018) study demonstrated that the Carbfix method may be applied to silicic rocks, such as dacitic and rhyolitic glass, in addition to the already proven use of Icelandic basalt.

Significant potential has thus been identified in the following countries: USA, Mexico, Nicaragua, El Salvador, Costa Rica, Italy, Japan, the Philippines, New Zealand, Indonesia, and Kenya. Notably, the sequestration capacities calculated are based on experimental conditions. Potential application of the Carbfix technology outside of Iceland is already underway with the development of the GECO project’s demonstration sites (see above).

Interested in Science?

If you are interested in Carbfix's scientific background, we have available Scientific Papers the Carbfix team has published over the years, as well as PhD, MSc, and BSc theses here.