Thanks, it's off grid but onto a temporary fix to feed a caravan while a bungalow is built. There's never going to be any grid connection so I'm thinking a smaller system not registered to MCS for the summer, then the rest of the panels on the roof and commissioned over the winter to whatever the Fit is then. That way he gets free electric over the summer (which is his main concern now) followed by 16p, maybe 14p by early next year (because the bungalow will be at least a C) rather than 8.9p if we register it before August.
Does that make sense? Strangely enough he's not really concerned about Fit but I'd like to get him the best deal we can, especially when he's got another 2 buildings going up next year he wants panels on.