Mounting panels to metal roof

[Supervstech]

Is Your Metal Roof Suitable for Solar Panels? - Roofrite

Solar Panel Issues on Metal Roofs Are you thinking of having solar panels installed on your galvanised metal roof? Read on to see why this isn’t such a great idea… So, you’ve done all the research you can to work out the best deal for your situation: you’ve worked out the kilowatts required per...

www.roofrite.com.au

While I am sure galvanic plays a part, the runoff from the water will do exactly the same thing.

I'm glad my metal roof is aluminum...

 

[Supervstech]

Get a large sheet of plywood or anything that can collect water, and have the end of it dump onto the sheet metal.
Where the water contacts the roof the zinc will wash off and you will have a rust spot.

 

[Supervstech]

Even better, get a piece of metal roofing and place it under the gutter downspout...
Same effect.
And, yes the aluminum gutters would also have the galvanic effect, so use plastic gutters and downspouts...