Anyone fitted solar to a narrowboat with a curved/radius roof before?

I'm looking at putting together a small solar setup on a hired narrowboat I'm converting to live aboard part-time — similar vibe to the shepherd's hut project I've been tinkering with on land. The curved steel roof is giving me headaches though. Flat rigid panels obviously aren't going to sit flush, and I'm not sure whether to bother with semi-flexible panels or just mount a small frame that holds rigid panels slightly elevated.

Currently thinking around 400W total — maybe two 200W rigid panels on a fabricated mild steel frame, powder coated to keep the rust off. Victron MPPT 100/30 for the controller as that's what I've got confidence in from my other builds. Battery side I'm looking at a 100Ah lithium, possibly Fogstar given the price point. Total roof width on these boats is only about 2.1m so space is tight.

The semi-flexible panel route does appeal for the cleaner look — less snagging on bridges and low-clearance tunnels — but I keep reading mixed reviews about them delaminating after a year or two in damp UK conditions. Anyone actually running them long-term on a boat rather than a van or static setup?

Hey @Jock30, good project! The curved roof is definitely the main headache with narrowboats. A few things worth knowing:

Flexible panels are the obvious answer but honestly their efficiency and longevity aren't great — I'd avoid cheap ones especially in a damp marine environment.

What a lot of boaters do instead is use aluminium Z-brackets and angle rigid panels slightly to follow the curve rather than lying flat. You lose a tiny bit of optimisation but nothing dramatic, and you get proper monocrystalline panels that'll last.

Also worth thinking about: narrowboat roofs get walked on constantly for lock work etc, so whatever mounting system you use needs to handle that without the panels becoming a trip hazard or getting cracked underfoot.

Cable routing through the roof is trickier than on land too — decent waterproof glands are non-negotiable on a boat. What sort of wattage are you thinking?

Del72 | Posts: 847 | Location: Midlands

Great project @Jock30! To add to what @Chunk85 mentioned — one thing people often overlook with narrowboat installs is the orientation trade-off. You'll likely end up mounting panels fairly flat to avoid fighting the curve too much, which does hurt your output angle, but honestly on a boat you're more often chasing reliable daily yield than peak performance anyway.

Also worth thinking about tilt-leg mounts that let you angle panels when you're moored up, then lay flat when cruising under low bridges — there are some lovely low-profile hinged options doing the rounds at the moment.

Canal & River Trust have guidance worth checking too, particularly if you're on hire licence rather than your own registration, as there can be stipulations around roof modifications.

What battery chemistry are you leaning towards? Makes a difference to how you size everything else.