Based on a Technology Deep Dive presentation by Jim Mann, CEO of UNDO, in February 2023
Overview
- Enhanced rock weathering (ERW) removes CO2 from the atmosphere by spreading large quantities of selected and finely ground rock material onto extensive land areas.
- ERW mimics and accelerates (50,000 x) the natural weathering processes of silicate rocks.
- The carbon removal takes place over a 50-year “weathering curve”; with approximately 13% of removals taking place in the first year, and 90% over 20 years.
- The rock is a waste by-product of mining and quarrying – it needs to be ground to dust.
- Basalt generally has low heavy metal content and can be spread on agricultural land.
- Other approaches use olivine that weathers more quickly but contains heavy metals.
- Suitable locations depend on: rock mineralogy, weathering conditions and proximity of quarry/mine to suitable land.
- The UNDO ERW value chain includes: quarry/mine owners, haulage companies, agricultural contractors and land-owners/farmers.
Scalability
UNDO has the ambition to contract a GT of removals by 2030. Scale possible because:
- rock waste is a vast resource – <10% of basalt mined annually needed to get to GT scale
- uses existing mining, quarrying and agricultural processes and infrastructure
- offers significant co-benefits (increased crop yield, jobs in rural areas, use of waste, ocean alkalinity)
| PROS | CONS |
| Leverages existing infrastructure | Open system makes it hard to measure |
| High permanence | Extensive analysis of rock mineralogy needed |
| Huge scalability potential | Removal takes place over multiple years |
| Cost reduction – potential to get to < $100/T | All OPEX costs are upfront – negative cash-flow |
| Very low energy requirements | Validation hard because science is new |
| Abundantly available rock | Long education process for buyers |
| Clear co-benefits | |
| Use of by-product | |
| Can be developed in Global South |
Costs (UNDO)
- Currently from $101/T to $160/T, excluding MRV
- Current MRV costs are $70-80/T, but targeting single $/T costs once models validated
- Targeting a selling price of <$150/T within the next few years
- UNDO has undertaken a project to define a pathway to $100/T
Co-benefits/SDGs
| Co-benefit | SDG# | SDG |
| Silicate rock powders increase crop yield (up to 40%) and help to mitigate soil nutrient depletion. | 2 | Zero Hunger |
| Projects can done with small-scale farmers and provide a cheap alternative to traditional fertilisers. | 8 | Decent work/economic growth |
| Can bring agronomic benefits for farmers, supporting regenerative practices, and recycles mine waste | 12 | Responsible consumption & production |
| Scalabale, affordable, permanent carbon removal | 13 | Climate action |
| Assists with ocean alkalinisation and improve the nitrogen cycle. | 14 | Life below water |
| Improves soil health and mitigates land degradation associated with BAU farming practices. | 15 | Life on land |
Market maturity
- A dozen companies globally working on ERW
- UNDO is market leader having sold approximately 30,000 tonnes of (pre-methodology) removals.
- The rest of the market has sold approximately 6-7KT of removals (Lithos, Eion, Greensand).
- Buyers are “climate forward” companies (eg Stripe, Microsoft and XTX Markets) and resellers, including SuperCritical, Wren, Ceezer and Cur8.
- UNDO is aiming to contract approximately 1MT of removals by the end of 2024 and spread enough rock to capture those 1MT by the end of 2025.
MRV
- Standards are critical to identify high quality projects, offer assurance to buyers, identify bad actors.
- Measurement is done through a modelling process, reflecting many different scenarios. Model outputs need to be calibrated, or “trued up” with field data.
- Life-cycle analysis (LCA) accounts for grinding, transport and spreading to get net removals.
- Measuring carbonate storage in solid form is easier; measuring dissolved bicarbonates is more challenging – UNDO is working on measurement innovations.
- Current MRV costs are high – associated with truing up the model; insurance can lower costs.
- Identifying third-party verifiers with the right background is a challenge.
