Iceland’s Clean Energy Technologies: Geothermal Energy, CCUS and Carbon-to-Stone Technology

Context

India is exploring cooperation with Iceland to develop geothermal energy and carbon management technologies. The initiative aligns with India’s National Policy on Geothermal Energy (2025) and efforts to reduce emissions from energy-intensive industries.

1. Geothermal Energy

• Definition: Energy derived from the Earth’s internal heat for electricity generation and direct heating.
• Working: Underground heat warms water, producing hot water or steam that can drive turbines to generate electricity.
• Enhanced Geothermal Systems (EGS): Use engineered wells and water circulation to extract heat from hot rocks where natural reservoirs are inadequate.

• Other Applications: Geothermal heat can be used in greenhouse cultivation, food processing, aquaculture and ground-source heat pumps.

India’s Geothermal Potential

• Estimated potential: About 10.6 GW (theoretical).
• Survey: The Geological Survey of India (GSI) has mapped 381 hot springs and identified 42 promising geothermal sites.

• Geothermal Provinces: India has 10 identified geothermal provinces, including the Himalayan, Naga-Lusai, Andaman and Nicobar Islands, Son-Narmada-Tapi (SONATA) and Cambay Graben provinces.
• Potential Sites: Puga and Chumathang (Ladakh), Manikaran (Himachal Pradesh), Tapoban (Uttarakhand) and Tattapani (Chhattisgarh).

• Policy support: The National Policy on Geothermal Energy (2025) promotes research, pilot projects, international technology transfer, and the reuse of abandoned oil and gas wells.

2. Carbon Capture, Utilisation and Storage (CCUS)

• Definition: Technologies that capture carbon dioxide () from industrial emissions or the air, use it in industrial processes, or store it underground.
• Key Processes:

• Capture: Separating from industrial gases or directly from the air.
• Utilisation: Using in chemicals, building materials, and other products.
• Storage: Injecting into underground geological formations for long-term storage.

• Enhanced Oil Recovery (EOR): Injecting  into oil reservoirs to extract more crude oil. However, burning the additional oil can offset some climate benefits.
• Key Distinction: Carbon capture and storage (CCS) focuses on capturing and storing CO₂, whereas CCUS also includes its utilisation. Using CO₂ in products does not necessarily result in permanent carbon storage.

3. Carbon-to-Stone Technology: Carbfix

• Concept: Converts captured CO₂ into stable solid carbonate minerals for long-term underground storage.
• Working: CO₂ is dissolved in water and injected into basaltic rocks, where it reacts with calcium-, magnesium- and iron-bearing minerals to form solid carbonates.
• Carbfix (Iceland): Its pilot project demonstrated that over 95% of injected CO₂ mineralised within two years.
• Scientific Basis: This process is known as carbon mineralisation. It accelerates natural rock-weathering reactions that convert CO₂ into mineral forms.

Suitability for India

1. Potential Sites: The Deccan Traps, rich in basaltic rocks, may support carbon mineralisation, subject to site-specific studies.
2. Site Requirements: Suitable rock chemistry, permeability, water availability, and geological stability.
3. Technology Suitability: Carbfix-type mineralisation requires reactive rocks such as basalt; not all geological formations are suitable.

Significance for India

1. Reliable Energy: Geothermal energy can provide round-the-clock power, complementing variable solar and wind energy.
2. Industrial Decarbonisation: CCUS can reduce emissions from hard-to-abate sectors such as steel and cement.
3. Long-term Carbon Storage: Mineralisation converts CO₂ into stable solid minerals, reducing the risk of leakage.
4. Energy Security: Domestic geothermal resources can diversify India’s energy mix and reduce fossil-fuel import dependence.
5. Technology Transfer: Cooperation with Iceland can support research, pilot projects, and technology development in India.

Challenges

1. High Capital Costs: Substantial investment is required for deep drilling, CO₂ capture, and storage infrastructure.
2. Geological Limitations: Variations in underground rock formations can affect geothermal energy output and carbon storage capacity.
3. Water Scarcity: High water requirements for CO₂ injection may limit the deployment of Carbfix-type technology in water-stressed regions.
4. Regulatory Uncertainty: Inadequate clarity on environmental clearances, underground storage rules, monitoring, and long-term liability can delay projects.
5. Uncertain Climate Benefits: Energy-intensive capture processes, incomplete CO₂ capture, and potential storage leakage can reduce the overall emissions benefits.

Way Forward

1. Resource Assessment: Conduct geological surveys and pilot projects to assess feasibility and costs.
2. Technology Transfer: Partner with Iceland to improve drilling, engineering, and carbon monitoring.
3. Regulatory Framework: Establish clear rules for CO₂ storage, environmental safeguards, and long-term monitoring.
4. Targeted Deployment: Prioritise CCUS in hard-to-abate industries while expanding renewable energy and energy efficiency.

FAQs

Q1. What is geothermal energy?

Ans. Energy derived from the Earth’s internal heat for electricity generation and direct heating.

Q2. What is the difference between CCUS and carbon-to-stone technology?

Ans. CCUS covers carbon capture, utilisation and storage, while carbon-to-stone converts CO₂ into stable solid carbonate minerals.

Q3. Why are basaltic rocks important for carbon storage?

Ans. Basalt contains calcium, magnesium and iron-bearing minerals that react with CO₂ to form stable carbonates.

Q4. Does CCUS always reduce carbon emissions?

Ans. No, its climate benefits depend on capture efficiency, energy use and long-term storage security.