Solar panels on a narrowboat — flat or tilted?

Flat's the only sensible choice on a boat unless you fancy adjustable panels that'll rattle themselves into the canal by March. Winter angle loss is real but honestly, you're already getting shaded by bridges half the time anyway — might as well accept the compromise. I've got 400W flat on my static caravan setup and even that's a faff to keep clean without climbing on the roof constantly; on a moving vessel you'd go mental. The real win with flat is you're not creating a wind catch that'll have mooring ropes under tension, and you can actually walk across your roof without tripping over brackets. Stick a decent Victron MPPT controller on it and it'll squeeze what it can from whatever angle the sun bothers to show up at.

Flat's practical but you'll definitely notice the winter hit. I've been running 400W on my setup (mix of Victron and Renogy) and the angle loss is real — talking 20-30% less generation Dec-Feb depending on cloud cover.

Thing is, tilted adjustable rigs do exist without being total nightmares. Seen a couple boats with proper hinged brackets that don't rattle. Not cheap though, and you're adding weight to the roof which matters on narrowboats.

Honestly? Go flat unless you're genuinely bothered by winter performance. Simpler = fewer things to fix when you're moored up. The real gains come from having enough panels rather than obsessing over angles. I'd rather have 500W flat than 300W tilted.

@CopperSparky — winter generation near Brum is grim no matter what. Just plan your battery depth-of-discharge accordingly.

Been through this exact dilemma on my van conversion, and it's similar enough. Flat's your friend on a boat—anything tilted becomes a maintenance nightmare and catches wind like a sail. Yes, winter output dips, but I've found a modest tilt (15-20°) on adjustable brackets sorted mine without the rattle risk @HeatherWalker mentioned. Worth the occasional tweak rather than losing half your generation November through February.

What's your power budget looking like? On my garden office I went flat initially, but the winter performance was grim. Since boats move around, could you get away with portable panels you angle manually when stationary? Might be worth the hassle if you're moored for stretches. What's your typical usage—heating, refrigeration, electronics?

Flat's the way on a narrowboat—tilted mounts are a nightmare for headroom and canal bridges. Winter's rough either way, but flat lets you stack panels efficiently. I'd prioritise battery capacity over panel angle. Victron's MPPT handles the variable angles well enough. What's your actual power draw looking like?