I'm sure it said recovery was 2 every 20 mins originally and several people have written articles saying this, yet now it's 2 every 6 mins. If that's per house that's a maximum energy increase of 12 per 6 mins - which is a lot.
In addition it seems you can change residence. Is this true because I assumed from the statement that you couldn't go back to being a nomad that you couldn't change residence "Once a citizen becomes a resident of a city, they can no longer turn back to their “nomad” status." Does it just mean you must move to another residence?