Anyone else finding their panels completely useless this past week with all this grey weather?

Yeah it's been pretty grim hasn't it. My cabin setup has been absolutely crawling along this week — normally pulling decent amps even on overcast days but the past few days have been something else entirely.

Running a Victron SmartSolar 100/30 and I've barely seen it break 4-5A at peak. Panels are facing south-southwest which usually helps catch the afternoon light but when there is no light, there's no light 🤷

Had to actually think about what I'm running for the first time in a while. Cut back the laptop usage and been a bit more careful about the lights in the evening. Not a disaster but it's a reminder that you can't just assume the batteries will be topped up.

Fogstar cells in my DIY battery pack are holding up fine — the storage capacity is doing exactly what it's supposed to do during these lean patches, which is reassuring.

Bit curious though —

• Has anyone done the maths on whether a small wind addition is actually worth it for UK conditions?
• Or do most of you just overbuild the battery bank and ride it out?

Feel like wind turbines always look attractive on paper but then you read the real-world output numbers and they're... underwhelming unless you're somewhere properly exposed.

Hopefully next week brings a bit more brightness. The forecast looks marginally better but I'll believe it when I see 15A on the controller again.

@LesCrane — worth being precise about what "useless" actually means here. Panels don't stop working in grey weather, they derate. The question is how much.

Been monitoring my shepherd's hut array closely this week. 400W of panels (Renogy mono) running through a Victron MPPT. Even on the worst days I'm still seeing 8-15% of rated output — so roughly 30-60W. Not glamorous, but it's not zero.

The real issue is cloud type. Uniform grey stratus is actually more predictable and consistent than partial cloud, which causes weird voltage spikes and sags that can confuse cheaper charge controllers.

If you're genuinely seeing near-zero output, I'd check:

• Soiling on the panels (this time of year, algae and grime accumulate)
• Controller logs for any fault codes
• Whether your battery SOC is affecting acceptance rate

What controller are you running?

@SomersetVanLifer is technically correct but also nobody asked for a physics lecture, mate.

My static on the Isle of Sheppey has been generating enough to run a phone charger and absolutely sod all else — genuinely considered just plugging into shame and running an extension lead from the neighbour's garage.

Fogstar battery sat at 43% for three days straight, Victron BMV giving me the kind of readout that makes you question your life choices.

Bottom line: yes, grey weather makes panels "useless" in the way that a chocolate teapot is technically still a teapot. Pedantically functional, practically pointless. If you're not running a decent battery bank you'll feel every cloud personally.

@SomersetVanLifer has a point worth finishing though — diffuse irradiance still matters, and actually where your panels are pointed becomes disproportionately important in these conditions.

My shepherd's hut runs 400W of Renogy mono on a tilt-adjustable mount. Steepened them to about 70° last November and I pick up meaningfully more in December/January grey than my neighbour's flat-mounted setup does. High angle catches what little sky brightness there is rather than just staring at cloud base.

That said — this week specifically has been genuinely dire. Fogstar 48V lithium sitting at 40% and I've had to be sensible about the kettle. Victron Cerbo showing daily yields around 180Wh where I'd normally expect 600+ even in dull conditions.

So yes, useless is an exaggeration, but significantly compromised is entirely fair. Tilt your panels if you can, and accept that January in the UK requires a backup plan.

Yeah the boat's been suffering too. Fogstar cells are holding up but I'm barely seeing 10-15% of what I'd normally pull on a cloudy-but-bright day.

@SolarJunkie curious where you're going with the diffuse irradiance point — I've wondered whether panel angle matters more in these conditions. Mine are pretty flat on the cabin roof which I suspect isn't helping when the light's that scattered.

Victron app's just been depressing to look at all week tbh.

Feel for you all — it's been a rough week for sure. Worth checking if you've got any partial shading making things even worse than they need to be; wet leaves and general grime on the panels can stack up surprisingly fast this time of year and really kill what little light there is. Gave mine a wipe down yesterday and picked up a noticeable improvement even in these conditions. Also if you're not already, keep a close eye on your battery state of charge and ease off non-essentials before you go too deep — recovery time in this weather is brutal. @Fogstar_Fan 10-15% sounds about right for what I'm seeing too. Just one of those weeks where the generator earns its keep, I'm afraid!