@odd All fair questions. So our panels are German but I take the point of the carbon footprint of solar panels in general. Roughly it takes about three years for carbon payback of a panel. 10 years for gross installation cost payback (in our case) and 30-40 years lifetime so maybe 35 years of energy production fully free of any carbon cost. Norway looks like you get roughly 1000kwh/m2. Thats half Spain but still not too bad. Finland is I think 800-950kwh/m2 and that gives us a payback time of ten years. So in other words tell your friend if he has the money up front and he has a roof with decent solar profile there is nothing to stop him. Phew!