Anyone else finding their solar completely useless this January?

We're about three weeks into the new year and I'm genuinely starting to question my whole setup. I've got two 200W panels on the roof facing south-ish (maybe 15° off due to the van layout) and a 200Ah lithium battery, and I'm getting maybe 10–20Wh on a good day right now. Yesterday was completely overcast and I generated a grand total of 4Wh. Four. The fridge alone is pulling around 30Ah a day.

I knew January would be rough but I wasn't quite prepared for this. I've ended up running my engine for 45 minutes every couple of days just to keep the battery above 30%, which feels like a massive defeat. I've got a Victron SmartShunt so at least I can see exactly how bad things are in real time, which is both useful and deeply depressing.

Just wondering what everyone else is doing to get through the worst of winter — are people using shore power when they can get it, running generators, just accepting the engine idling situation? Or have any of you added extra panels specifically to help with the low-angle winter sun? Thinking a ground-mounted panel on a tilt frame might help but not sure it's worth the hassle for just a couple of months.

@Kate1970 January on a boat is brutal for solar, I'll tell you that much. Even perfectly south-facing panels are giving me maybe 20-30 minutes of genuinely useful output mid-day if I'm lucky. The low sun angle is the killer — panels rated at 200W assume optimal conditions, not a sun that barely clears the treeline at noon.

The 15° offset isn't your problem, honestly. It's barely worth worrying about this time of year.

What's your battery chemistry? If that 200Ah is lead-acid you're effectively working with 100Ah usable, which disappears fast. Swapped to a Fogstar Drift 100Ah lithium last winter and it transformed things — not because of the solar, just because I could actually use the full capacity.

Shore power or a small genny becomes a necessity in Jan/Feb for most of us. Solar's basically a supplement until March.

Hey @Kate1970, don't despair! January in the UK is genuinely the worst month for solar - low sun angle, short days, and seemingly endless cloud cover. Your 15° offset will cost you a bit but honestly it's not your main problem right now, it's just the time of year.

What's your battery state looking like by morning? And have you got any backup charging - shore power, alternator, wind? This time of year I'd treat solar as a supplement rather than your primary source until at least late February.

Worth checking your panels are clean too - surprising how much a layer of grime or even just condensation residue knocks things back. Mine picked up noticeably after a quick wipe down last week.

Hang in there, the days are already getting longer! 🙂

@Kate1970 genuinely curious — what's your battery capacity versus your daily consumption? Because I wonder if the solar is trickling something in but you're just burning through it faster than you realise in January.

My static caravan setup was the same last winter — panels doing something but felt like nothing because the fridge, lighting and phone charging were all chewing through it. Turned out I was pulling about 80Ah more than I thought daily 🙈

Have you got a decent battery monitor? My Victron BMV-712 was a proper revelation for actually understanding what's going in vs coming out. Without one you're basically flying blind and assuming the worst.

Also — are you running any 12V LED lighting or still on older bulbs? That made a surprisingly big difference for me over winter.