Methane (CH4) = sum ((n small scale*EFs) +(n mediunscale * EFm)+(n big scale * EFb)); the convert to C02 (using GWP); 4m3 = 4ton CO2e. 1,500 bio-digester plant per year (include:\small=1450; medium= 45; large=5) >contributing people s livelihood as well as better economy. USD 12,750,000. Benefit in term of gas or fuel-wood reduction (250 USD/4m3plant /year/HH and get slurry (1,5-2,0t/4m3plant/HH).