Said in my first post i found this interesting, I'm even more interested now!
The whole point of my meeting with my accountant was to discuss these issues. He does not feel it is an issue to split the solar side as it turning out to be run in a completely different way to the rest of my business. I won't go into detail further about that. It is completely legit, you don't get the contracts we are getting if it is not. But I will not put out there the business model.
My accountant has said though that if I am going to split, it is advisable to do so sooner rather than later. There is an interim period between having a business sideline and then that becoming a business all on its own. Particularly with solar, my accountant and I feel that for now, we are running things correctly.
Spc in the UK is such a new industry that no one really knows yet if it will take off initially and then implode. There is no point setting up a company for it to go bust a little further down the line. That said, we realise that if we are to split, it is advisable to do so sooner rather than later because as some have you have said, the legal lines become a little blurry.
Personally, I have always worked as legit as I can and this solar thing will be done with equal diligence, if it happens.