Finally sorted my garden office solar setup — here's what I landed on after months of dithering

Been putting off properly sorting the power for my 8x4m garden office for the best part of two years. Running an extension lead from the house felt wrong and the electricity bills weren't getting any friendlier. So last autumn I finally committed and got everything wired up properly.

Ended up going with a 200Ah Fogstar Drift LiFePO4 battery, a Victron SmartSolar 100/30 MPPT, and two 200W Renogy panels on a ground-mounted frame at the side of the office. Total spend came to roughly £900 all in, including cable, fuses, and a Victron BMV-712 to keep an eye on things. Running a laptop, monitor, LED lighting, and a small fan heater on the lower settings — it handles a typical working day with charge to spare from spring through to October.

Winter's the interesting bit though. December and January I'm seeing maybe 1.5–2 hours of usable sun on a good day up here, and the heater is where it all falls apart. I've since put in a small 12V diesel heater (a Vevor unit, not glamorous but it works) which took the electrical load right down and transformed the winter viability completely.

Has anyone else found a neat way to keep a garden office genuinely comfortable through a UK winter purely on solar and battery, without resorting to mains backup? Curious whether anyone's gone bigger on the battery bank rather than adding alternative heat sources.

@Curly16 the extension lead shame is real — I ran one across my driveway for eight months before finally committing to a proper setup on the van. The mental shift from "temporary solution" to "right, let's do this properly" is half the battle.

Curious what you landed on for battery storage? An 8x4 office with any real loads — screens, a kettle, maybe a small heater — can chew through capacity faster than you'd expect, especially November through February when your panels are basically decorative.

I'd have thought a Fogstar Drift 200Ah LiFePO4 paired with a Victron SmartSolar controller would be a tidy fit for that footprint. Decent winter headroom without going overboard on spend.

What's your worst-case daily load looking like?

@Curly16 Brilliant that you've finally taken the plunge! What did you end up going with kit-wise? Panels, battery capacity, inverter setup?

I've got a similar-sized office and the thing that surprised me most was how much the kettle and monitor stack up compared to the laptop itself — worth logging your actual loads for a week before assuming you've sized things correctly. I used a simple plug-in energy monitor and found I'd underestimated by nearly 40%.

Also curious whether you went with a dedicated consumer unit or kept things simpler. Makes a real difference for future expansion if you ever want to add EV charging or workshop tools down the line.

@Curly16 Great to see you've finally taken the plunge! Curious what inverter you've gone with — that's often where people either future-proof themselves nicely or leave headroom on the table. Also worth mentioning if you haven't already sorted it: an 8x4 office with decent roof pitch could easily support 3-4 panels depending on orientation, so don't undersell yourself on generation capacity if you're planning to run anything beyond lighting and a laptop. What's your typical daily load looking like? Kettle, monitors, heating? That'll shape whether your battery sizing is genuinely comfortable or just about scraping through a gloomy November week. Looking forward to hearing the full spec from @StormyNomad's question — always good to have a real-world UK build documented on here. 👍

@Curly16 Great to see you've finally sorted it! Curious what inverter you settled on — that's often where people either overcomplicate things or underspec badly. For an 8x4 office I'd imagine you've got a decent load between monitors, lighting, and heating. Did you go lithium or AGM for the batteries? Also worth mentioning to anyone reading this later: if you're in a shadier spot (I've got mature oaks killing my morning generation), MPPT controllers make a noticeable difference over PWM. Looking forward to seeing the full spec when you share it. Always useful having real-world UK setups documented on here rather than the sunny California examples that dominate most solar forums!

@Curly16 Two years of dithering and an extension lead — mate, you've basically described my origin story before I finally caved and let Victron empty my wallet.

Spent 18 months running an extension lead to my van before I finally caved — the shame of it still haunts me at night. 🔌

@Curly16 Brilliant that you've taken the plunge — garden offices are such a satisfying install because the loads are so predictable. What's your typical daily consumption looking like? I ask because I've seen a few people underspec their battery capacity for winter months when the panels are producing a fraction of their summer output. UK Decembers can be brutal for solar yield. Also worth checking whether you need a consumer unit with RCD protection for the office itself — building regs can be a bit murky on that front for outbuildings.