We are looking at installing solar PV panels on the roof, but we have a Eurotray roof like this https://archipro.co.nz/project/euroline-battenlok-standing-seam-roofing-peninsula-roofing-and-scaffolding   . The roof has totally concealed fixings where the roof trays are fixed with clips on the sides and has a batten over the  top of the clips. Apparently you can't drill through the trough of the tray. The roof is supported on a plywood substrate and apparently the roof trays have a lot of movement and expansion as it has a long span. I am guessing they would have to fix into the sides of the fixing clips, through the batten covers that cover the clips. Anyone done this and know how it is best to fix it. I don't want to install solar and then have an issue with the roof leaking down the track, because that will likely negate any saving  in installing solar. 

I can see that you can get laminated PV cells that stick to the roofing tray, as shown at https://www.facebook.com/watch/?v=562557377676363 But not sure how much of a thing they are these days. I have seen a roof that had these installed about 10 years ago but I don't think it was very efficient and I think all the power just went back into the grid..

I am guessing many solar installers wouldn't have much of an idea and will likely just drill fixings straight into the roofing tray troughs and use a lot of sealant etc if not advised. Also the house is on triple phase power so not sure if that is an issue.