They key here is that it was dried out. Thats part of the problem with biomass producing energy. The amount of energy it takes to dry it so it can burn is greater than the energy output of the now dry mass.
If its producing methane gas, a comparable example would be the LA city or county WWTP. It produces enough methane each day that burning it through their energy plant basically allows it to be energy neutral in that it produces enough energy to offset its use of energy.
I remember watching farmers in Turkey drying cow pies on the roof of their home and every space not used for anything else. It took a long time for it to sun dry.