Its first large project is the production of biomethane from the medium-maturing H133 biomass sorghum, a very robust hybrid which requires low amounts of inputs. Sorghum is a genus of many tropical grass species often associated with semi-arid regions. There are grain, sweet, fiber and now hybrid sorghums bred specifically for biomass production. These hybrids have been made to thrive in European conditions. The H133 grows to a height of 4 to 4.5 meters (13-15ft). Contrary to maize, miscanthus, switchgrass or other energy crops, the hybrid sorghum requires no irrigation and less fertilizer but trials show it yields between 30 and 40 tons of dry matter biomass per hectare (12 – 16 tons/acre) (graph, click to enlarge).
According to Energreen the H133 sorghum is highly suitable for the production of biogas, yielding around 14,000 to 16,000 cubic meters per hectare. Depending on the CH4 content of the gas, this amount of biogas, when upgraded to natural gas quality comes down to an average of 7600 cubic meters of methane, enough to power a car for 80,000 kilometers. This is much more useable energy than can be obtained from converting biomass into liquid fuels. One hectare of H133 sorghum based biogas provides enough renewable, carbon-neutral fuel to power five average French passenger cars for an entire year: