Previously, I had attempted to fix a roof leak under a solar panel from beneath the tiles. It failed.
Back to the drawing board. I decided to get on the roof and look under the solar panel again after all. I checked out the repair done by the electrician and immediately found issues.
Complicating the situation, there was an old antenna anchor. Immediately behind the anchor the tile had cracked, which was hidden by the silicone on top. I had previously attempted to repair the leak using black silicone and a dentist's mirror, but the silicone wasn't in good condition anymore and there were opportunities for water to get around it and into the crack. An electrician had also added some in an attempt to fix it (white silicone).
The solution: dump in more silicone. This was a bit tricky, I had to lie between the two rows of solar panels without the sharp corners of the panels biting my butt. And then smooth the silicone down so that hopefully it would actually keep water out of the roof space.
In two days Bureau of Meteorology is predicting a downpour, so fingers crossed 🤞😅😬
Update: We had 9 mm of rain on 2 August and no leaks found! 🥳