We build technologies that fix the climate.

Engineered carbon removal. Built and operated in the UK.

Black and white illustration of a geometric shape with curved lines and a square grid overlay.

At Nellie, we're driven by a singular purpose to mitigate the negative effects of climate change.

We've developed bioengineered carbon dioxide removal at speed and at scale. We use proprietary biomass growth, processing and sequestration channels to remove carbon dioxide from ambient and point sources which we then turn into biochar and biogenic aggregates to offer exceptional additionality and permanence.

High-Integrity Carbon Removal

Purchase high-integrity carbon dioxide removal directly from Nellie.

Our engineered carbon removal is produced in the UK using our proprietary microalgal systems, with captured carbon converted into durable PhycoChar® biochar for long-term storage.

Purchase available carbon removal directly through our CORC Shop, or contact us to discuss larger volumes, forward purchases and multi-year offtake agreements.

LEARN MORE

A chalkboard sign with a wooden frame that advertises fresh, captured carbon credits available at Nellie, written in green, yellow, and white text.

1000 tCO₂ Annual Capacity

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200+ Year Permanence

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UK Production

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Patented Systems

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1000 tCO₂ Annual Capacity | 200+ Year Permanence | UK Production | Patented Systems |

Award Winner 2025

Award Recipient 2024

2024 & 2025 Nominee

Award Winner 2024

See what we do.

Our friends at Razor were kind enough to feature Nellie and our carbon dioxide removal systems as part of their recent film on innovative clean technologies.

Have a look at our pilot site and the science behind fixing the climate.

A man, dressed in black, using a ladder near large containers with a sign that reads "Nellie Mwyndy Cross Carbon Dioxide Removal Facility." The scene is outdoors, next to a factory with a gray wall and brick exterior.

Our first DAC site.

We're operational from our first hybrid DAC / BECCS site located at Mwyndy, South Wales, United Kingdom. Find out more about the technology we’ve built to remove carbon dioxide from the air.

Aerial view of Nellie's factory, surrounded by green grass, trees, and a winding pathway. There are vehicles and storage units visible near the factory.

We use proprietary biological and mechanical engineering to capture carbon dioxide by producing biomass at speed and at scale. We then process and sequester this in biogenic aggregate channels.

Growth

We build photobioreactors and we build them big. Inside them, we have a unique (and patented) set of ingredients and tools that create biomass very quickly. As the biomass grows, it removes carbon dioxide from the gaseous inputs.

Processing

Once the biomass has reached its optimal growth, we remove it from our photobioreactors and process and treat it using a variety of methods to make sure it's suitable for our long-term carbon dioxide sequestration channels.

Sequestration

The processed biomass feedstock is then put through one of several systems to generate either a biogenic aggregate or biochar. This end product is then used in the agricultural and construction supply chains and the captured carbon is stored away for over a thousand years.