Does anyone actually get usable solar through a UK winter, or is it basically pointless?

I've been running a 400W panel setup on my T5 (two 200W mono panels, Victron 100/30 MPPT, 200Ah lithium) since spring and it's been brilliant. Topped up every day without really thinking about it. But now we're heading into November and I'm starting to wonder what to realistically expect.

Last week I got maybe 10–15Ah on a clear day, which honestly surprised me on the upside. But we had four days of solid grey overcast before that where I barely saw the Victron move off float from the previous charge. I'm in the East Midlands if that makes any difference.

I'm mainly using the van at weekends — fridge running 24/7 (roughly 30Ah/day), a bit of lighting, phone charging, the usual. Has anyone got actual figures from December/January running a similar setup? Wondering whether I need to accept I'll be hooking up to shore power on longer trips, or if panel angle makes enough difference to bother rigging something more adjustable.

@T5Build winter solar in the UK is genuinely grim but not completely pointless — just set your expectations accordingly.

On my static van in the Midlands, December/January I'm getting maybe 15-30 minutes of "proper" sun equivalent per day. Your 400W setup might yield 100-150Wh on a decent winter day, basically nothing on overcast ones.

The real problem isn't just low irradiance — it's the angle. Panels flat on a van roof are basically useless when the sun barely clears the treeline. If you can tilt them even 45° you'll notice a difference.

I run a small Honda genny as backup October through February, no shame in it. Lithium helps massively over AGM for partial states of charge, so at least you've got that sorted. Don't expect the Victron to be doing much heroic work though.

@T5Build on my shepherd's hut setup I'd say December/January you're looking at maybe 20-30% of what you got used to in summer. Some days genuinely nothing usable.

That said, a few things helped me massively:

• Tilt angle — steepen your panels for winter sun, makes a real difference
• Panel cleanliness — low sun angle means grime hits harder
• Fogstar lithium holds voltage better in cold than my old AGMs did

Worst case scenario for me is a gloomy week in January where I'm running the genny for an hour or two. But I've never had a dead system.

Your 200Ah should buffer you fine if you're not running mad loads. Just don't expect your Victron app to look anything like it does in July 😄

Really echoes what @FX_Power is saying from my own experience. The killer isn't just the shorter days — it's the sun angle. Even on a clear December day the sun barely gets above 15-20° here, so your panels are working at a steep disadvantage unless you can tilt them right up. I've found manually adjusting panel angle seasonally makes a noticeable difference, something like 60° in winter versus 30° in summer. Also worth knowing that overcast days still produce something — just don't expect it to cover heavy loads. Plan your usage around it rather than against it, keep an eye on your state of charge, and maybe have a backup charging option (vehicle alternator, hookup, small genny) for the really grim weeks. Your lithium will handle the partial cycling fine at least.

@T5Build what the others haven't mentioned yet is how transformative keeping your panels clean becomes in winter. Low sun angle means any film of grime, moss, or even just road muck from motorway runs absolutely kills your output — far more than in summer when the light's hitting more directly. I scrub mine down every couple of weeks through December-January and genuinely notice the difference the next day. Also worth checking your MPPT settings; some benefit from adjusting absorption voltage slightly in cold temps, and actually cold clear days can push panel output above rated wattage briefly. Not enough to solve the fundamental problem, but every amp counts when you're scraping 15-20Ah on a grey Tuesday in January.

@T5Build one thing nobody's touched on yet — cold temperatures actually help your panels perform better when you do get sun. Lithium efficiency drops in the cold, but crystalline panels genuinely produce closer to their rated wattage on a crisp clear January day than they ever do baking in August heat.

The real winter killer on a mobile setup is parking angle. At home I can tilt my panels to compensate for the low sun angle @RayCross mentioned, but a flat roof mount loses you significant harvest. Even propping panels at 50–60° in December makes a measurable difference — I've seen my Victron VRM logs go from 180Wh to 450Wh on identical days just from repositioning.

Your 200Ah lithium capacity is actually decent insurance here. Size your winter consumption to reality, not summer habits.

Really good point from @LDVCamper there. Building on that — it's worth setting realistic expectations around what you're actually asking your system to do. In summer you're probably barely noticing consumption because generation masks everything. Winter forces you to actually audit your usage properly, and most people find they can trim quite a bit without real discomfort. LED lighting, a decent sleeping bag instead of an electric blanket, timing any heavier loads around midday if you do get a decent window. Your Victron setup gives you great data — spend a week genuinely watching the app and you'll quickly see where the power's actually going. Winter solar isn't pointless at all, but it shifts from passive to active management.