Southampton is under an hour from base and fully covered. The bulk of its owner-occupied housing is 1930s semis and post-war houses in Bitterne, Sholing, Shirley and Bassett, with hipped roofs that take a 3.5 kW system cleanly and a garage or side return for a battery. The Victorian terraces of Portswood, Freemantle and Inner Avenue are narrower, often north-south, and are where we are most likely to say a smaller system or a battery alone is the better buy.
Southampton has a large rented sector and a lot of flats, which is where the EV chargepoint grants do most of their work: £500 per socket for renters and flat owners with a parking space, and £500 per socket for landlords across up to 200 sockets a year. Commercial solar on the industrial units around Nursling, Millbrook and the airport is sized from the bill and pays back in around five years.