Energy consumption would be pretty much determined by the outside vs preferred temp-delta, so brewing heat loving Belgian beer in the dead of winter would make those heaters run all the time I suppose, even with serious insulation. Northern Germany‘s climate doesn’t make cooling an issue for anything else than food most of the year, but I’ll keep that in mind, thanks.

My batch size is limited by the size of my equipment, I can’t really go beyond 20, maybe 25 Liters.