Managing the increasing amount of waste generated in urban spaces is a common challenge to cities worldwide.
Since March 2017, Stockholm has been working to address this problem by opening the first large scale biochar plant. Stockholm Biochar project uses park and garden waste to produce biochar and renewable energy. Residents provide garden waste to the city, which produces biochar – a charcoal-like product that sequester carbon in soil for thousands of years.
Biochar is a great soil conditioner that retains water, air and nutrients in the soil. Once in the soil, biochar is a carbon sink that contributes to a greener city and that decreases the levels of carbon dioxide in the atmosphere for hundreds to thousands of years. The city becomes greener while the residents make an important contribution to the environment and the climate. The energy becomes heat for the city's district heating network within Open District Heating TM – a project to recycle excess heat in Stockholm city.
So far, there is only one plant for transforming biochar into fertilizer (located in Stockholm, Sweden) - it has been internationally recognized and awarded for its innovative thinking. Four additional biochar plants are planned to be completed in the following years. These five plants are expected producing 7 000 tons of biochar by 2020, sequestering 25 200 tons of CO2 (the equivalent of taking 3 500 cars off the road) and producing corresponding 25 200 MW/hour of energy (the equivalent of heat for 400 apartments). Within eight years the project will deliver a revenue on the city’s investment estimated approximately over 854 000 EUR.
Biochar is a great soil conditioner that retains water, air and nutrients in the soil.
Once in the soil, biochar is a carbon sink that contributes to a greener city and that decreases the levels of carbon dioxide in the atmosphere for hundreds to thousands of years.
Stockholm Water and Waste (SVOA), Stockholm Exergy and the City of Stockholm.
Bloomberg Philanthropies, Stockholm Water and Waste (SVOA), Stockholm Exergy and the City of Stockholm.
Stockholm Biochar Project's goal is to produce heat for 400 apartments and to create a carbon sink corresponding to the yearly carbon dioxide emissions from 3500 clean cars - a small but important action to save the world. Using biochar in green areas of the city, carbon sinks, plants grow easily, and storm water infiltrates efficiently, helping to manage flooding. Furthermore, a greener city contributes with a whole array of auxiliary benefits such as cleaner air, increased biodiversity while combating heat island effects.
Stockholm City has received many requests from other cities and organizations that are interested in replicating the program. As a result, the Biochar team has published a replication manual and checklist for reference. Investigations are already underway into how to develop this system using other kinds of waste (e.g. by-products from forestry and agriculture, straw, sewage sludge and horse manure) and to extend the use of biochar to other applications (e.g. building materials).
Tech trend: Bioengineering,
Societal trend: Local networking, Sustainable responsibility, Circular society
This case can be linked to SDG no. 7 - Affordable and clean energy - as biochar is a renewable energy source, no. 11 - Sustainable cities and communities - by contributing to carbon sinks, more efficient infiltration of stormwater, etc., as well as no. 13 - Climate action - as a greener city contributes to cleaner air, increased biodiversity while combating heat island effects.
No interview - using online information only.
https://www.stockholmvattenochavfall.se/en/current-projects/development/biochar/
https://nordregio.org/sustainable_cities/stockholm-biochar-project/