Mine have basically given up and gone on strike — producing enough to power a toaster if you're very optimistic about the toaster's mood.

The thing is, I've got a decent 5kW array here and even on these grey November days it's genuinely depressing watching the inverter barely tick over. Had a mate round yesterday, pointed at the Victron display and said "look, we're generating enough to charge a phone... in about three hours."

What's kept me sane is having a proper battery backup (Lithium, LiFePO4) because I learned this lesson the hard way my first winter. Now when the panels decide to have a lie-in, I've got stored energy from the better autumn days to fall back on. Also running a small backup generator for the shepherd's hut when the battery dips — not ideal, but beats freezing in the dark.

The real kicker is realising how much your setup needs that winter storage. People often size their batteries for summer nighttime use, then wonder why January arrives like an unwelcome in-law.

Few questions for the rest of you:

What's your backup strategy looking like? Are you running batteries, generators, or just accepting that winter means grid connection for most folks?

How much are you actually getting off your panels right now? I'm genuinely curious if anyone's got a setup that's holding its own in this weather.

And has anyone tried repositioning panels or upgrading tilt angles for winter? Might be worth a thread on its own.

Yeah, winter's brutal on output. I'm running a 4.8kW array here and I've just accepted December-February are basically write-offs for anything beyond the obvious—battery top-ups, not heavy loads.

The thing nobody mentions though: check your panel angle. Most installations are set for summer generation, so winter sun hitting at a shallow angle gets absolutely hammered by efficiency loss. If you've got adjustable mounting (I rigged mine on hinges), even a 15-20 degree seasonal tilt adjustment can squeeze another 20-30% out on clear winter days.

Also worth checking—dust, moss, bird muck. Sounds daft but I found a decent moss patch on mine last week that was blocking a third of one panel. Soft brush and some mild soapy water made a noticeable difference.

That said, if you're getting single-digit kWh days consistently even accounting for angle and cleanliness, might be worth checking your Victron's data logs for shading patterns you've missed. Trees grow, shadows shift.

What's your battery setup looking like?

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@PanelRoger - Mate, that's pretty much par for the course I'm afraid. Winter's the real test of an off-grid system, not those glorious June days everyone bangs on about.

The thing that helped me was getting realistic about what a 5kW array actually produces when the sun's barely getting above the horizon and we're getting proper grey skies. I'd suggest having a look at your actual generation figures for this time of year - might shock you less if you can see the pattern.

Have you got battery storage to carry you through? That's where the real difference shows. Also worth checking your panels aren't covered in leaves or bird muck - happens more often than people think and can tank output surprisingly quickly.

What's your backup heating sorted like? That's usually where folks struggle most in winter.

Mate, you're not alone. Winter's genuinely the acid test for off-grid systems — sounds like you might need to look at your battery storage strategy if you're not already.

A few things worth considering: Are you running any backup heating or generation alongside the panels? Most of us find a small wind turbine or petrol generator absolutely essential for the really grim months. Even a 1kW wind gen makes a huge difference on those grey, still days when solar's basically useless.

Also worth checking — are your panels at the right angle for winter sun? A lot of folk adjust theirs seasonally to capture more of that low winter light. Every bit helps.

What's your battery capacity looking like? That's often where the real problems hide. If you've got decent storage, at least you can make the most of those occasional sunny days.

Keep your chin up — February's nearly here! 🙂

Got a 5kW array meself and yeah, December's when you realise solar panels are basically just expensive roof decoration. The real question is what you've got behind them — if you're relying solely on panels in winter you're already losing.

Battery capacity and a backup system separate the smug off-gridders from the ones eating beans cold in the dark. My Victron setup with a decent battery bank (and a petrol generator I'd rather pretend doesn't exist) keeps things ticking along. What's your storage situation looking like? That'll tell you whether you're actually stuffed or just experiencing normal winter misery.

@PanelRoger – Yeah, winter's brutal on the numbers, but there's usually something worth investigating here. A 5kW array should still be pulling decent power on overcast days, not just "toaster mode."

Have you checked your actual output figures against the panel spec? Dirty glass makes a shocking difference in UK winter conditions – grime accumulates and you lose 15-20% efficiency without realising. Worth a clean.

Also worth validating your inverter's readings against a proper meter. I've seen dodgy DC wiring and loose connections cut output by half, and they're easy to miss.

If everything checks out mechanically, then yeah, it's just the reality of our latitude and cloud cover. That's when proper battery sizing and diesel backup become your friends. What's your battery capacity sitting at currently?

Got a narrowboat so I know all about rubbish winter generation. What's your tilt angle? Flat-mounted panels in December are practically useless — sun's at about 15° elevation on a clear day and you're catching maybe 30% of rated output at best even then.

Also what's your actual battery situation? Sometimes the panels aren't the problem — if your bank's already full by 10am there's nowhere for the power to go and the MPPT just throttles back. Victron MPPT controllers make this dead obvious in the app if you know what you're looking for.

What charge controller are you running and what does your VRM or whatever monitoring you've got actually show? "Basically rubbish" could mean several different things and it matters which one it is.