Went to move a heater at a house I rewired last year and noticed they'd had pv panels fitted on the roof of their house and the roof of their holiday let. I had a look at the install inside and found this. The RCD 2 way board is fed from a circuit in a dual RCD d.b. This is all I took pictures of, there was way more rough elements! The owner said that they did the 2 installs in 3 hours! No wonder!!
(sorry if the pictures are the wrong way!)
(sorry if the pictures are the wrong way!)