30
Home biogas: turning food waste into renewable energy
(theconversation.com)
everything about energy production
It's a quote from the article, not "my" family.
I think any such numbers are really subjective and depend on your cooking style. If you want to cook lentils for hours each day then the gas is probably insufficient.
My mistake, sorry!
I was more thinking of the 2kg of food waste per day he's apparently generating, because that... seems like a lot.