It depends on the green waste and things like water content.
For a biogas reactor digesting poop the power is something like 6.9 kWh per litre of biowaste
Just copy pasted from some spreadsheets we had on modelling biogas production for a population of 50k maybe…
Biogas production
110,348.44 kg/day [5]
220,696.88 l/day
6.90 kWh/l biogas
1,522,808.50 kWh/day
1,522.81 MWh/day
63.45 MW power production
9.69 kWh/person/day
other research [6]
0.5 m3/kg TS
55174.2 m3/day
biogas producing rate (humans - poop) [6]
5 dimensioning a biogas reactor http://www.sswm.info/sites/default/files/reference_attachments/BRC%20ny%20Design%20Biogas%20Plant.pdf
6 POO DENSITY http://www.ircwash.org/sites/default/files/321.4-85EM-2161.pdf