Marine algae have the scale to make a meaningful difference to climate change. Beneficial coastal algal blooms feed almost all fisheries on our planet and already contribute 20% to photosynthesis-based global atmospheric CO2 reduction every year (more than all forests combined). By replicating these blooms year-round in hot, coastal deserts, our algae can significantly contribute to ‘additional’ plant-based carbon fixation and storage without displacing existing agricultural land or ecosystem resources, even at the gigaton scale.
Our approach combines the affordability of nature-based systems with the durability and measurability of engineered systems.
An algal starter monoculture is grown in the lab. This is where we precisely control environmental conditions and kick-start the ‘Bloom’ phase – a state in which algae grow exponentially.
After 10 days in the lab, the blooming algae are transferred into a greenhouse. This offers some protection and means the organisms can acclimate to the natural environment without sacrificing growth rate.
After the greenhouse we move the organisms into outdoor ponds, where they spend the remaining five days growing rapidly in the large outdoor production ponds. Due to the exponential growth, nearly 90% of the total biomass is produced in these last 2 days.
The dried algae is collected, weighed, and put into specially lined landfill sites located above projected future sea levels.
The landfills are designed to slowly remove any leftover moisture from the algae and salt mixture. We continuously monitor them so that any unexpected release of emissions is detected and accounted for.
Storing carbon in this way has several benefits:
1) The storage sites are co-located with our biomass production, so the transport of material is straightforward.
2) We follow established regulations to responsibly manage the landfills.
3) The biomass is available for physical verification, making it easy to demonstrate that it is durable and has not degraded.
Half of the CO2 removed by system is taken directly from the atmosphere above the ponds. The rest is taken from the bicarbonate in the seawater that is pumped into them.
Our process does not change the seawater's alkalinity or chemistry. When the seawater is released back to the ocean, it quickly restores its bicarbonate pool, removing the second half of the CO2 from the atmosphere. 85% of this rebalancing takes place with four days, and we confirm it through direct measurements and computer modelling.
The algae are filtered out of the final pond by passing the water through screens. These retain a concentrated biomass 'slurry' whilst allowing filtered seawater to pass through. The filtered water that returns to the shallow ocean surface is de-acidified and promotes biodiversity restoration.
We pump the biomass slurry produced at harvest up a drying tower, which sprays the mixture into the hot, dry desert air. The particles rapidly dry as they float back to the ground and take the form of a dry, salty powder.
The dried algae is collected, weighed, and put into specially lined landfill sites located above future sea level projections. It remains highly stable over time because it has a high salt content and other physical properties that prevent degradation.
We employ a ‘triple lock’ mechanism to guarantee that buried biomass remains stable. The buried composite is dry and has low water activity, which inhibits degradation. It is also extremely salty and naturally acidic. Long-term storage has been shown by naturally preserved biomass that has remained stable for thousands of years under similar conditions. This means it can be permanently stored in simple desert landfills.
Sign up to our newsletter to keep up to date
