Anaerobic digestion of food and green waste yields ~0.22 toe/tonne of biogas, and manure yields up to 0.04 toe/tonne [1]. (toe = tonnes of oil equivalent)

Australia wastes 300 kg/year/capita of food [2] (across the entire supply chain, from farm through fork)

Americans generate 90 kg/year/capita of yard waste [3]

That's 1.07 kg/day, for 0.24 kg of oil equiv.

The average adult produces ~0.4 kg/day of manure [4], for 0.02 kg of oil equiv.

All up that's 0.26 kgoe/day, or 0.3 L [5] of petrol.

The most efficient scooter I could find (Honda Activa-i) does around 70 km/L (165 mpg)

So optimistically, you could generate 21 moped kilometers per day of biogas. In more normal units, that 3 kW/h or 11 MJ.

[1] https://www.iea.org/reports/outlook-for-biogas-and-biomethan...

[2] https://www.environment.gov.au/protection/waste/food-waste

[3] https://www.waste360.com/mag/waste_yard_waste_4

[4] https://www.emedicinehealth.com/ask_how_much_does_poop_weigh...

[5] 1 kgoe = 1.16 L of petrol