OpenIDEO is an open innovation platform. Join our global community to solve big challenges for social good. Sign Up / Login or Learn more

Four-Season Carbon-Negative Urban Farms, Powered By Biochar!

Use biochar stoves to burn waste biomass and create both heat and Biochar, a carbon-negative (wow!) fertilizer. The heat allows for year-round growing, and the Biochar would be used to build more productive soil. It's a closed-loop double whammy.

Photo of DeletedUser
3 3

Written by DeletedUser

Urban Biochar Farms will create vibrant economies, right in the heart of blighted urban areas. The farms will use local labor and sell their produce in CSA (Community Supported Agriculture) boxes year round, providing a much needed source of healthy food to urban food 'deserts' and creating a profit. The boxes will be complete with recipes drawing on the heritage of participants and stories around those meals.

The farms will be able to grow food all year long by having simple greenhouses that are heated by the burning of waste biomass and production of biochar either in a small simple stove made with parts from a hardware store (similar to the Geo Biochar Stove, designed by fellow OpenIdeo member Sai Bhaskar Reddy Nakka ) or by purchasing a larger kiln from RE:Char . The biochar will then be mixed with compost and used in the soil to boost soil productivity by increasing water and nutrient retention and cationic exchange capacity (fancy phrase for healthy soil).

The Biochar is carbon-negative because it’s formed of carbon taken out of the air by photosynthesis and captured in a super stable charcoal form in the soil. The farms will therefore be able to sell carbon-negative crops at a premium to local restaurants interested in the latest eco-foods.

Urban Biochar Farms on rooftops are also very lightweight which makes it easier to get permits to place farms on roofs. Utilizing lightweight growdomes would be a perfect match .

What resources (money, time, people, technology, etc) will your concept need to be successful?

One full-time project fellow would be able to get this project off the ground by :Establishing a demo in a current urban farm :Partnering with existing farms who would like to be founding members :Setting up the Crowd-Sourced Toolkit :Securing Press :Building an online presence to spread the Urban Biochar Farm solution. This fellow would be funded and found through a kickstarter campaign that allowed people to fund the project, and advertise for the position. Local supporters of the kickstarter could pre-order their CSA boxes and local restaurants could pre-order carbon negative produce. Partnerships with biochar stove designers, biochar application experts, and urban farm advocates would ensure the success of the project.

What steps could you take to implement this idea today?

We could partner with existing urban farms and provide them with the information they need to make their own low-tech biochar kiln that will heat a greenhouse and produce a powerful fertilizer/soil amendment. These partnership would be the founding members of our crowd-sourced toolkit described below.

How can your idea be scaled so that it's implemented in cities around the world?

A crowd-sourced toolkit could be easily and cheaply built using a site like This is similar to what WindowFarms has very successfully created ( This community could share biochar stove designs, biochar application tips, greenhouse designs and other urban farming tips in order to build a comprehensive toolkit for newcomers. The community could connect virtually and celebrate each others victories utilizing this low-capital platform.


Join the conversation:

Photo of DeletedUser


You are the designer of the "Joy to the World" institutional scale biomass heater?

It is an extraordinary simple, clean and intense heater.

View all comments