24/25 🌍 Mammoth – Iceland's Giant Direct Air Capture (DAC) Plant Covert Carbon Dioxide into Stones

🧭 Brief

Mammoth is currently the world's largest operational direct-air-capture-and-storage facility. It features innovative modular DAC design, geothermal-powered operations, and mineral storage in basalt. While it's an important tech demonstration and a step toward gigaton-scale carbon removal, it is still early in performance and cost optimization.

Operator: Climeworks (Swiss) in partnership with Carbfix (Icelandic)

🔧 Key Facts

• Groundbreaking: June 28, 2022; core build completed within ~18 months
• Operations Begin: First CO₂ capture started May 8, 2024; ramp-up continues through 2024
• Capacity:
  • Projected Performance: 36,000 t CO₂/year (≈9× larger than Orca)
  • Full deployment: 72 collector "snap-in" containers; 12 initially online in May 2024, the rest will be operational gradually

⚙️ Technology & Operations

1. Air Capture: Fans pull in ambient air through modular collector units to adsorb CO₂.
2. Energy Input: Powered by low-temperature heat and electricity from the nearby Hellisheiði geothermal plant via ON Power.
3. Storage: CO₂ dissolves in water and is injected about 700 m underground into basalt rock, where it permanently mineralizes into stone through Carbfix's mineral storage process.
4. Verification: Third-party certification independently confirms the trustworthiness of carbon removals.

🎯 Strategic Role

• Represents a major milestone toward Climeworks' "megaton by 2030, gigaton by 2050" ambitious plan.
• Aims to deliver certified, high-quality CO₂ removal capacity to corporate customers (e.g., Microsoft, Stripe, JPMorgan).

💡 Context & Constraints

• Scale: Removing 36,000 t/year makes a local impact, roughly equivalent to removing about 7,800 gas cars each year, but it is very small compared to the roughly 35 billion t of global emissions.
• Cost: Current capture costs remain high (≈$1,000/t), with goals to reduce to $300‑350/t by 2030 and $100/t by 2050
• Performance Issues: A recent Icelandic probe found Mammoth captured only about 750 ton gross (around 105 t net) in its first 10 months, well below its projected capacity. However, Climeworks attributes this to the early ramp-up phase and mechanical issues that are now being addressed.
• Critic Concerns: Many experts caution that direct air capture should complement, not replace, aggressive emissions reductions.