You already have a whole bunch of holes in the roof and if they are sealed up properly they do not leak. The same applies to any new holes you might create. There's no reason to expect a new hole to create a new leak if you used the right sealant and an appropriate cover plate. For me, that means a generous application of Dicor lap sealant and some kind of cable entry plate like Winegard makes or a similar piece of plastic/metal large enough to cover the hole(s) plus an inch or two. Many are able to feed the solar output wires down the fridge vent and then into the basement creating no new holes other than where the solar panels are "caulked and screwed" to the roof.
