Project Erica: The Continued Saga of the Solar

It is incredible (even inconceivable), not to mention slightly ridiculous, how much time has been spent on the question of the solar panel. It should have been so easy:

 Okay, perhaps I didn’t think it would be *quite* this simple…

The latest instalment in the saga is that before ordering the new solar panel, from a company called Photonic Universe, I sent them a few technical queries, one of which was really just a point of clarification. In their installation instructions for their ordinary flexible panels, they mandate that you must fill in all of the ridges in the roof so as to provide a flat surface for mounting, but in the instructions for the reinforced panel (which is what we’ve bought) this is only a recommendation, going on to say “spaces between ridges on a vehicle roof can be filled in […] this will make mounting easier and quality of bond better.” I just wanted to check that ease of mounting and quality of bond were the only reasons to fill those gaps, because to my mind it’s advantageous to leave them open (ventilation; no chance of rain water being stuck under the panel, rotting Erica’s body if there is any defect in her paint layers).

I really didn’t expect the answer I got, which was that we did need to fill those gaps, because otherwise the panel would flex where unsupported risking damage to the solar cells. I had a few issues with this answer:

1. It wasn’t the answer I wanted!
2. Surely having the panel firmly bonded either side of the 45mm gaps (with the bonding covering of 75% of the panel’s area) wouldn’t give scope for damaging flexion?
3. This is a reinforced panel, into which is integrated a sheet of anodised aluminium, which is sold as being one of the most robust flexible solar panels on the market – what’s the point in doing that if it still can’t cope with spanning small gaps?
4. The difference in wording of the instructions between the ‘normal’ semi-flexible panel and the reinforced one was marked: ‘you must’ versus ‘you can’ fill the gaps.

So, this morning (after another period of taking measurements on Erica’s roof and drawing diagrams; if any of our neighbours have witnessed our antics with our cardboard replica panel, they must be wondering what we’re up to) we had a phone call with the Product Advisor, feeling sure by that point that he must have thought we were referring to the non-reinforced panel.

But no – the answer still came back that we had to fill those gaps, otherwise we would risk invalidating the warranty. Or we could bond a solid sheet of something to the roof to provide a flat base before bonding the panel to that. “So what’s the point of selling a reinforced panel if that reinforcement doesn’t perform any useful function?” we asked and “Why do your instructions state this is optional if not doing it would invalidate the warranty”?

We got as far as the advice that “It’ll probably be fine if it’s not more than a 45mm gap it has to span”, before he went off to consult an engineer. Finally a definite and sensible answer: there is no problem with mounting the panel spanning the gaps; it will not cause it any damage.

Thank goodness for that! We took delivery of the panel this afternoon and our fingers are crossed that the forecast for a dry day on Saturday holds, so that we can finally get it mounted*.

(*If only we can make the decision as to whether to mount it along Erica’s length (fewer dips to span, but a longer cable run required) or across the width (more dips to span, but a shorter cable run).