As im aware, Refinery doesnt have any function ingame like a storage tank, so one of the idea is quite basic and heavily inspired by how it was in CNC
For refinery - 1st Idea is the team that has control of it, will get constant income of certain amount of cash in certain time period (dunno if including first time capture bonus cash is good or not), for example mission makers can change amount of money that faction will get and in what time (just like factory produce time)
That extra cash would probably split up between all players in team, similar to how it would when someone donate funds
2nd idea is like it was in Generals, where refinery would give a player a discount on units, in NO it could be done the same but for team wide bonus, so for example mission makers could edit how much % discount team will get for owning that refinery will it affect munition/aircrafts. While effects from various refineries wont stack, but refinery with bigger % will work primary
For Storage tank - its quite tricky, because right now fuel is not restricted and refueling not cost you anything. So like before, first time capture would give a team cash bonus, while holding it would reduce build time of units in the factory (how much time is reduced can be changed)
Im not certain about "passive" effect for storage tank, would it be useful or not, so feel free to suggest your ideas