https://www.cenergysolutions.com/biogas-digesters - 1 m³ biogas = 6 kWh thermal energy #### Fuel [[work cart - village living]] - biogas has 22MJ energy / m^3 - ~30% engine energy efficiency - 5 MJ/hour - 1 hr / 1.0 m³ #### Water Heating - 1 m³ 10 liters of water from 20°C to 60°C - high efficiency system: - biogas pipeline loss = 2% - water heater combustion efficiency = 95% - heat transfer and water heating efficiency = 95% - distribution efficiency = 90% - overall efficiency = ~ 80% - 6kWh/m³ × 0.8 = 4.8kWh/m³ - Energy to heat water = `Q(kWh)=m(liter/kg water)⋅c(Wh/kg°C)⋅ΔT(°C)` - 1⋅1.16⋅(60−20)= .0464kWh to heat 1 liter of water from 20 -> 60 - 4.8 (kWh/m³) / .0464 (kWh/L) = 103 liters of water per m³ - 100 L/m³ - 3.785 L / 1 Gallon - 40K gallons hot water per day x 3.785L/Gall / 100 L/m³ = 1514 m³/day - 1m³ to boil and sustain 4.67 gal water from 140°F #### Cooking - 0.25m³/meal - 3000 meals per day = 750m³/day - 4 meals/m³ #### Electricity - ~35% efficiency generators - 1 m³/day × 6kWh/m³ × 0.35 = 2 kWh/day - 2 kWh/m³ #### Generation [[waste management - village living]] - 1.3-2.0 kg of organic waste per person per day (urine + feces) - ~1000 kg daily society production - ~.04 m³ of biogas is produced per kg of human waste, - 40m³ of biogas per day #### Generation [[livestock - village living]] | **Animal** | **Daily Waste (kg)** | **Biogas Yield (m³/day)** | | ---------- | -------------------- | ------------------------- | | **Pig** | 2-4 kg | 0.15-0.30 m³ | | **Cow** | 25-30 kg | 1.0-2.0 m³ | | **Sheep** | 1-2 kg | 0.03-0.05 m³ |