TTCR (willow coppice with very short rotations) in Brittany
Conference support for the 4th Biomass meeting “What resources for the biofuels of tomorrow” organized by Valbiom in November 2007.
The willow TTCR, what is it?
- A perennial culture, lifespan of 15 - 20 years
- Planting in spring (15 cuttings / ha)
- Winter after planting, coppicing
- Harvest every 2 to 3 years
- Yields: 8 to 12 t DM / ha / year
- Energy recovery
- Purification of soil and sludge
The TTCR in Sweden, example of the municipality of Enköping.
- Municipality of 20 inhabitants
- 75 ha of TTCR for the treatment of wastewater and the heating of housing estates
- Input by effluents: 330 mm / year, 250 kg N / ha / year and 16 kg P2O5 / ha
- Performance of the purification system proven since 1994
TTCR in Brittany, Wilwater program
Experimental program Wilwater, TTCR 100 ha to demonstrate the purifying interest of the culture of willow TTCR, and the economic and environmental interest of this purifying system.
Wilwater Project Results
a) Crop adapted to a treatment of weak and balanced effluents
b) Encouraging results for the use of TTCR as tertiary treatment and to delve into the role of soil in effluent treatment
(c) More nuanced interest in the application of sludge:
- exports comparable to those of annual crops, with more extensive management
- Reserved for special cases, where the interests of willow cultivation are multiple (non-food cultivation, energy recovery, etc.)
d) The interest of culture as a whole: do not forget that the TTCR is above all a culture intended for the production of energy!
Our opinion on TTCRs
Both technical and financial difficulties limit the development of this sector. Especially since there are more interesting alternatives such as high-growth plants such as miscanthus since it allows annual harvests and requires much less load per hectare and finally, its dry matter yield is greater. .