The project on converting ‘verge grass to biogas’ has advanced to the next scale of verge harvesting research and development.
In 2017 Lincolnshire County Council secured a grant to design and build a UK specific prototype verge harvester and to test aspects of the unit design and harvesting / logistics. The trial was carried out in 2018 with three participating Anaerobic Digestion plants. Together these entrepreneurs have formed a joint venture called Lincolnshire Verge Harvesting Ltd. LVH Ltd matched the grant and thus amassed a viable budget to design, build and test the prototype machine.
The machine began trials in the early summer. Notwithstanding the inevitable need for several workshop ‘rest periods’ whilst modifications were made the machine worked throughout May, June and July. Cut and collection was successfully carried out over three parts of Lincolnshire. Each harvest area was within 10 km of the receiving Anaerobic Digestion plant. A total of 360 t of verge biomass was harvested from approximately 760 km of grass verge. A very cold spring (the beast from the east rampaged through Lincolnshire in March) lowered soil temperatures and plants had barely begun to recover before the accumulating moisture stress of the summer heat wave stunted their growth. The extent of the effect became clear when the 2016 trial data was used to predict biomass yields and indicated it should have been nearer to 1,000 tonnes. Nonetheless the machine’s performance improved throughout the trial period as the modifications were incorporated and driver confidence and experience increased.
With these experiences LVH Ltd will be undertaking further harvesting trials and machinery demonstrations in 2019.