Hi,
we have an off grid property (which will cost in excess of
£80k 
to grid tie so thats not going to happen) with an existing if bodged pv install (non fit registered) with batteries and diesel gen, space for panels isnt a problem as we have our existing 12 * 65watt panels mounted on the side of our barn (Lat 50°56'33.42"N lon 0°21'59.02"W) and there is still loads of space available.
We require a MCS install so we can claim FIT payments and reduce the cost of runny the genny
many thanks
Tim