Project Dates: 01.02.25 to 01.08.25

Flete Field Lab‘ s Biochar project turns waste wood from Flete Estate’s normal woodland management processes (such as trimming hedges and coppicing) into biochar that can be used as an alternative to synthetic fertiliser to enhance soil quality and reduce run-off and river pollution.

The project has so far processed 2,500kg of charcoal into biochar, which is the equivalent of 7,500kg of Co2 removed from the atmosphere, however there is scope for much more carbon to be sequestered if locally produced biochar could be produced and applied more efficiently.

Biochar has to be crushed to the right size to be incorporated properly to benefit the soil. There is an absence of appropriate mid-scale biochar crusher technology, with existing options being much larger (and more expensive) industrial-scale machines, so Flete Field Lab has designed an affordable biochar crusher to fill this UK gap.

DEF’s grant will support this new piece of equipment to be built and prototyped for use at the Flete Estate, South Devon to benefit neighbouring farmers, enabling them to add nutrients to their soil from local woodland waste. Once the design has been proven to work, it can be replicated to enable more farmers across Devon and the UK to benefit from using locally produced biochar.

Huge thanks to Olympus Power for generously donating to DEF to enable Flete Field Lab to develop this biochar crusher and increase the amount of carbon sequestered into local soil.

Image credits: Flete Field Lab

IMPACT SUMMARY October 2025

Project Activities:

• The project has developed a biochar kiln which was design was developedin-house, fabricated locally, and tailored tosmall-scale production needs.
• The finished machine has proven far more robust than expected, built from heavy-gauge steeland substantial components. This requiredextra assistance during assembly, but thetrade-off is a unit of exceptional durability. It isdesigned to withstand continuous use, roughhandling, and outdoor conditions, giving it along working life with minimal maintenance. While this required extra help with assembly, itmeans the crusher should provide many yearsof reliable service.

 

Project Outcomes: 

• The project has delivered a highly functionaland long-lasting machine, and has creatednew opportunities for knowledge-sharing andreplication with other biochar producers.
• A key achievement is solving a frustratingbottleneck in biochar production: breaking theproduced charcoal into particle sizesappropriate for incorporation into the soil.
• The crusher design could be sharedwith other community biochar groups,or there is potential to produce pre-builtcrushers as a product for other biocharmakers.