Tesla "slate" £1.50 each. Welsh slate can be ten times that. If every new build or extension had the tesla, sooner or later, we would have enough free energy to run the streetlights.......maybe?
I don't know, looking it up its about 40 USD a sqft plus the battery pack plus the additional installation cost and ancillaries by the sparkie. I'm not saying you wrong or anything but seems quite costly to me, not to mention how much will it cost to get rid of it when it's lifetime is up and how much emission created manufacturing it. Knowing how much sunny hours the UK got I don't think it's viable here, still if they offer grants and tax relief it might becomes more affordable.
I know lot of farmers got grants to put solar panels up on suitable land and buildings, councils were giving out planning on it easily, most was only interested in the feed back tariff
I might be completely wrong tho