Partnering to achieve Net Zero today

We make Net Zero a reality now, not in the distant future, because neither the climate nor your business can afford to wait.

Taking your business, and the planet, to Net Zero

Onnu diagram

Businesses are struggling to balance affordable energy with reliable green initiatives to reduce emissions and reach their ambitious Net Zero goals.

Onnu builds and manages hubs that manufacture biochar using breakthrough pyrolysis technology. Our operations generate excess energy, and if our hubs are situated close to an energy partner, it can be delivered as a fully sustainable, carbon negative heat or cold energy source for industry.

Why partner
with us


Each of our Hubs can annually avoid 1,500 tCO2e emissions and remove 2,000 tCO2e.

Affordable, stable prices

Secure competitive energy rates for up to 10 years.

Managed service

We’ll build and operate the whole thing, so you can concentrate on your buiness.

Stable, sustainable onsite energy

Pyrolysis diagram

Green Energy Hubs are pyrolysis plants co-located with energy customers and owned and run by Onnu as a fully managed service.

We take local waste biomass and manufacture biochar, enabling us to offer you secure, green energy that is affordable now, and future proofed against price rises in the future.

How is this possible? The production of biochar creates a large volume of excess heat - a typical plant produces up to 2MW of thermal or cold energy - which can be delivered to you as a carbon negative source of energy. Not only this, but the process of manufacturing biochar qualifies for carbon removal credits, which further help to finance the operation and lower the price at which we can supply energy to you.

Can Onnu energy work for you?

Let's see if there is a fit.

Find out more

Green Energy

Our Green Energy Hubs produce large amounts of excess heat which can be delivered as a fully sustainable, carbon negative energy source for your business.

More green energy


Biochar is a long-term store of carbon, and an effective soil additive improving plant yields and health. We are committed to producing it on a large scale to make a real difference in the fight against climate change.

More biochar


We build our plants with the most advanced technology from the worlds leading manufacturers, ensuring reliability and optimal performance.

More technology

Impact calculator

What do you currently pay for energy?


£ - per kWh

What are your energy requirements?


- kW


Over 10 years
(accounting for inflation)

Energy Savings

£ -

CO2 captured


tons CO2e

Emissions avoided
(from fossil fuels)


tons CO2e

Biochar manufactured



Waste diverted



Sustainable development goals achieved

Sustainable development goals affordable and clean energy
Sustainable development goals industry, innovation and infrastructure
Sustainable development goals sustainable cities and communities
Sustainable development goals responsible consumption and production
Sustainable development goals climate action

Carbon removal

Onnu is registered with both Verra and Puro.Earth. We follow the VCS or Puro’s Biochar methodology depending on which is best for the project, both of which secures the highest value Carbon Removal Credits for organisations looking to voluntarily offset their carbon footprint.

Latest insights

Our COP27 Preview - what we are hoping to see in Egypt

Our COP27 Preview - what we are hoping to see in Egypt

Carbon removal
Climate news

With the world distracted by war and economic troubles, here are the key developments we are hoping to see to keep the fight alive.

Read more
Carbon avoidance, carbon removal and CCUS explained

Carbon avoidance, carbon removal and CCUS explained

Carbon removal

Reaching Net Zero will take a number of approaches to reducing CO2 in the atmosphere. Here we explain what they mean.

Read more
How feedstock choice impacts biochar production

How feedstock choice impacts biochar production


Biochar can be made from a wide range of source feedstocks. Here we explain how they can affect the final product.

Read more

Our partners