Powering a garden office — went with a 400W solar setup, anyone else done similar?

Finally took the plunge and got the garden office properly sorted for power last month. Went with two 200W panels on the roof (south-facing, slight pitch), a Victron SmartSolar 100/30 MPPT, and a single 100Ah lithium from Fogstar. Total spend came to about £650 all in, which I thought was reasonable enough given what some installers were quoting me.

Day-to-day it's handling a laptop, a couple of monitors, LED lighting, and a small fan heater on the lower setting without much drama through summer. I'm seeing around 1.2–1.5kWh coming in on a decent day, which more than covers my usage. Where it starts to get a bit sketchy is the winter months — I'm in North Yorkshire so we get some properly grim weeks where the panels are barely doing anything useful.

Thinking about adding a second 100Ah battery to give me more buffer for those grey spells, or possibly a small wind turbine to complement the solar. Has anyone gone down the wind route for a garden setup? Feels like it could be more hassle than it's worth given the faff with mounting and noise, but I'd be interested to hear from anyone who's actually tried it.

Also curious whether anyone's found a sensible way to integrate a grid hookup as a backup without making the whole thing overly complicated — ideally something I can just forget about unless things get desperate.

Nice one @MoorRoger! Very similar setup to what I did for my workshop last spring. One thing worth mentioning — with two 200W panels you'll want to check whether you've wired them series or parallel, as it makes a real difference to how the SmartSolar handles low-light mornings. I went series and found the controller started harvesting noticeably earlier on cloudy days, which here in Yorkshire matters quite a bit! What battery capacity did you go with? That'll likely be your limiting factor come December rather than the panels themselves. Also curious what you're running off it — kettle and monitors are very different beasts!

Great setup @MoorRoger! One thing I'd add that nobody's mentioned yet — keep an eye on your battery state of charge during those grey November-February stretches. Even with a south-facing pitch, I was surprised how little I was generating through mid-winter on my similar setup. I ended up adding a small mains hook-up as a backup charger for the really grim weeks, just runs through a cheap Victron IP22. Means I'm not stressing about the laptop dying mid-Teams call when there's been a week of solid overcast. The SmartSolar is a cracking bit of kit though — the Victron Connect app gives you lovely data to obsess over! What battery chemistry did you go with? LiFePO4 makes a massive difference to usable capacity if you're still running lead-acid.

Been running something almost identical for my shepherd's hut for about 18 months now — same Victron SmartSolar controller, love how it integrates with the app for monitoring.

One thing I'd add specific to garden offices: if you're running a monitor or laptop charger, watch out for the surge draw when everything powers up simultaneously in the morning. Caught me out a few times early on until I staggered things a bit.

Also worth considering Fogstar Drift lithium if you're still on lead-acid — the difference in usable capacity is significant, especially through those grim November/December weeks when the panels barely see direct sun. My 100Ah lithium genuinely outperforms the old 150Ah AGM I had before.

What battery are you running @MoorRoger?

Great setup @MoorRoger! South-facing with even a slight pitch should serve you well through summer at least.

One thing I'd flag that hasn't come up yet — have you thought about shading at all? This time of year the sun sits lower and things like nearby fences, trees, or even the office guttering can cast shadows that really hammer your output disproportionately, especially with panels wired in series. Worth getting out there on a clear winter afternoon and just watching what falls where.

Also curious what battery chemistry you went with? That'll make a big difference to how you manage things through the darker months. @SophieHobbs74's 18 months of experience with the same controller is reassuring — Victron kit tends to just get on with it quietly, which is exactly what you want!

Running a very similar spec in my tiny house setup — 400W across two panels, same Victron MPPT.

One thing worth flagging that hasn't been touched on: cable sizing between your panels and the MPPT is often undersized in these installs. At 400W you're looking at potentially 20A+ depending on your panel voltage configuration, so make sure you're running appropriate 6mm² DC cable for any runs over about 3-4 metres. Undersized cable kills efficiency quietly — you won't notice it immediately but your harvest figures will be consistently disappointing.

Also worth checking whether your panels are wired series or parallel — with a 100/30 controller, series gives you higher voltage/lower current which actually reduces those cable losses significantly, provided your open-circuit voltage stays within the controller's 100V limit (check your panel spec sheet carefully for cold-weather Voc).