Im with you on rooftop PV, but Rooftop power isn't enough and will never be enough. That JLR plant is a good example, they out in a huge array and it's only a small fraction of their power drawn. They need more.
And ground mounted PV is absurdly cheap power. Rooftop PV is something like 2-3x more expensive per W.
A little is better than nowt and, for the average domestic consumer, roof-sited PV would be ample for a lot of their use.
The issue is still cost though.
Many skint themselves for "the house of my dreams", so they'll have no chance of buying PV too.
And renting your roof out to a PV provider is fraught with issues IIRC, especially if and when you come to sell the house.

