Methane loss comparison. Left panel: summary box-whisker plots highlighting the range in methane emission factors (%) from indicated functional elements. Right panel: summary box-whisker plots highlighting the range in methane emission factors (%) from various functional elements for site which utilized agriculture feedstocks. Bars left to right with corresponding colours: purple - Digester, yellow - cogeneration system of heat and power (CHP), green - upgrade units, blue - digestate storage, orange - feedstock storage.