Does anyone know if a 200W panel will run a small chest freezer during winter?

Running a small chest freezer on the narrowboat and trying to work out if a single 200W panel is going to cut it through the winter months.

The freezer is a Subcold 50L — draws around 85W when compressor is running but obviously it cycles, so average consumption is probably somewhere in the 30-45Wh range per hour depending on ambient temp.

My concern is the solar yield in winter. From what I've read, you're realistically looking at 1-2 peak sun hours in December/January in the UK, which on a 200W panel might give you somewhere between 150-300Wh on a decent day — and that's being optimistic with shading and panel angle considered.

Has anyone actually run this combination over winter? A few specific questions:

• Is there a realistic minimum battery bank size I should be pairing this with? Currently looking at a Fogstar 100Ah LiFePO4
• Would it make more sense to run the freezer off hook-up when moored at a marina and treat the solar as backup/supplementary?
• Does anyone use a Victron SmartSolar to monitor actual yield through winter and have real data to share?

The narrowboat also has a 230V shore power connection so I'm not entirely reliant on solar — but I'm trying to understand whether the panel alone could sustain the freezer on days when I'm away from hook-up, particularly if moored somewhere rural for a few days.

Any real-world experience much appreciated rather than just theoretical calculations — always seems to work out differently in practice.

@MasterProject welcome to the forum, narrowboat crew represent! 🚤

Short answer: it's going to be tight. Winter in the UK, you're realistically pulling maybe 30-50Wh per day from a 200W panel on a grim December day — and that freezer will want more than that over 24 hours.

From my own boat setup, I'd say you need decent battery capacity to bridge the gap overnight and through cloudy spells. What's your battery bank looking like?

A single panel is a great start but I'd seriously consider adding another 200W when budget allows — panels are cheap these days (Renogy do decent deals). Your Victron MPPT will thank you too.

Don't be disheartened though — loads of people run freezers off-grid, it just needs the full picture sorted! 💪

Really depends on where you're mooring and how much shade you're getting @MasterProject. Up north in December you might only be pulling 2-3 usable hours from that panel on a good day — so realistically 400-600Wh generation versus a chest freezer that could easily consume 1kWh+ daily once you factor in ambient temperature and how full it is.

The saving grace with chest freezers is they're relatively efficient and the thermal mass helps enormously — a well-packed freezer cycles far less frequently.

Honestly I'd say 200W alone is borderline risky for winter liveaboard use without a decent battery bank to buffer it. What's your storage situation? If you've got 100Ah+ of usable lithium you'll manage better than you think, especially supplemented by engine charging while cruising.

@MasterProject 200W in a UK December is basically a decorative panel 😄

Seriously though — you might squeeze 1-2 peak sun hours on a good day, so realistically 200-400Wh. Freezer cycling on and off could work if you've got decent battery reserve behind it.

Had a similar situation with my

@RetiredElectrician isn't wrong — I ran the numbers the hard way on my 57-footer last winter. The maths isn't just about the panel, it's about storage. A single 200W panel generating maybe 150-200Wh on a decent December day won't keep pace with a freezer cycling every 20-odd minutes overnight.

What saved me was pairing my panels with a Fogstar 100Ah LiFePO4 — enough buffer to carry the freezer through the dark hours without the engine running constantly. Without decent lithium capacity behind it, that one panel is fighting a losing battle.

@MasterProject the real question is what's your battery bank like? That's probably the bigger variable here than the panel output itself.