Biogas Production Calculator

Food waste yields about 600 cubic meters of biogas per metric tonne of volatile solids versus about 350 for crop residue, because food waste is more energy-dense and readily broken down by digester bacteria. Crop residue's higher lignin and cellulose content resists bacterial digestion, so a larger share of its volatile solids pass through the digester without converting to biogas within a typical retention time.

Total Biogas is directly proportional to Volatile Solids (%), since only the organic (volatile) fraction of the feedstock actually converts to biogas -- ash, grit, and other inert material contribute nothing. Raising Volatile Solids from, say, 60% to 80% while holding Feedstock (metric tonnes) fixed increases both Total Biogas and Methane output by the same proportion, since inert material is simply excluded from the yield calculation.

Yes, both. Each Feedstock Type carries its own methane fraction alongside its own biogas yield: animal manure produces biogas that's about 60% methane, food waste about 65%, and crop residue about 55%. Since Methane output is Total Biogas multiplied by that fraction, feedstock type affects the energy quality of the biogas, not just how much of it is produced per ton.

Electricity Potential multiplies Methane (in cubic meters) by 3.5 kWh per cubic meter, a figure reflecting typical combined-heat-and-power engine efficiency (methane has roughly 10 kWh of thermal energy per cubic meter, and around 35% of that converts to electricity in a standard biogas generator). CO2 Offset then estimates the emissions avoided by that much electricity displacing grid power at the U.S. average intensity of about 0.37 kg CO2 per kWh -- EPA's eGRID2022 summary tables put the actual U.S. national average total-output CO2 rate at 823.1 lb/MWh (0.373 kg/kWh); EIA's 2023 figure is close, about 0.367. More recent eGRID editions report a lower national average as the grid mix keeps shifting (eGRID2023: about 767 lb/MWh), so treat this as a snapshot tied to the eGRID2022 dataset rather than a permanently fixed factor.