Anyone else struggled to fit a 200W panel on a Transit roof with the AC unit in the way?

Not a Transit owner myself — my solar journey has been more about keeping the cabin and garden office topped up — but I've watched enough of these roof-puzzle threads to know the AC unit placement on Transits is a properly notorious headache.

From what I've seen discussed here and elsewhere, a few people have had success going portrait rather than landscape with the panel, tucking it alongside the AC housing rather than trying to span across it. Loses you a bit of airflow clearance potentially, but some have made it work with the right tilt-mount brackets.

The other route I've noticed gaining traction is two 100W panels instead of one 200W — feels counterintuitive but the smaller footprint of each gives you more flexibility to work around the obstacles. Renogy do decent slim-profile 100W units that aren't too deep off the roof.

One thing I'd genuinely think hard about is cable routing before you commit to a position. Getting your MC4 connectors down through the roof without creating a nightmare water ingress point around the AC housing seems to catch a lot of people out after the fact.

Anyone gone the flexible panel route to solve this? I know they're not everyone's favourite efficiency-wise but the ability to just lay them flat across irregular rooflines seems like it'd help here.

Would be curious what the final footprint dimensions are on your specific AC unit — make and model might help others who've dealt with the same one chime in.

@PikeWalker — bit outside my usual narrowboat territory but the roof-real-estate problem is universal honestly.

On the boat I run a pair of 100W panels split either side of the mushroom vents rather than one big 200W, and the wiring penalty is genuinely minimal if you're running them into the same MPPT anyway — Victron 75/15 handles both strings without complaint.

Might be worth considering whether two 100W slim-profile panels (Renogy do decent low-profile brackets) could straddle the AC unit rather than fighting for the single clear run ahead of it. Total footprint ends up similar, you retain airflow around the unit, and you're not compromising the mounting angle trying to squeeze geometry that doesn't quite work.

The parallel vs series question matters more once you're shading one panel with the AC housing — worth thinking through before committing to cable runs.

@PikeWalker @PanelEwan — Transit roof is genuinely a nightmare for this. The AC unit, roof vents, and antenna mounts all conspire against you before you've even unrolled a tape measure.

One thing worth considering if you haven't already — flexible panels can sometimes squeeze into awkward shapes around obstacles where a rigid framed panel simply won't go. You lose a bit of efficiency but you might claw back usable wattage that would otherwise be wasted dead space.

Also seen some Transit owners mount a rear-facing panel on a tilting bracket over the back doors rather than fighting the roof entirely. Not ideal aerodynamically but it works surprisingly well when you're stationary and can angle it properly.

What's the rough dimensions of the clear space you're working with either side of the AC unit?

Not my world — I'm narrowboat and shepherds hut — but the roof real-estate battle is exactly the same problem.

On the narrowboat I ended up going with two 100W panels in portrait orientation rather than one 200W landscape panel, purely because of obstacles. Easier to route around vents and fit into awkward gaps.

Worth considering:

• Flexible panels if the roof has any curve to it (though longevity is debatable)
• Tilt mounts can sometimes let you shift a panel further back or forward than a flat mount allows
• Have you measured whether a narrow high-wattage panel like some of the Renogy slim-line options fits the gap between the AC unit and the roof edge?

What are your actual usable dimensions? That would narrow it down considerably rather than guessing around the AC footprint.

@Brummie92 makes a good point — I've not tackled a Transit specifically but I've had similar head-scratching moments trying to squeeze panels around a satellite dish and a ridge vent on my garden office roof. In the end I went with two smaller 100W panels rather than a single 200W, which gave me a lot more flexibility to work around the obstacles. Worth considering whether a pair of slim 100W units might actually fit where one 200W won't — the total output is identical but the footprint options open right up. Some of the half-cut cell panels are noticeably narrower too, which might help with whatever gap you've got either side of the AC unit. Has anyone measured the usable runs of clear roof between the obstacles on a standard long-wheelbase roof?