Powering a Garden Office with Solar
A garden office is the hardest case in shed solar: it needs power every working day, through the exact months when panels produce least, for loads that cannot brown out mid-meeting. It is absolutely doable — but only one of the two routes suits most full-time users, and it is worth being honest about which.
What a working day actually consumes
Start with the real load profile, because it is gentler than most people fear — right up until heating enters the room. A laptop draws 30–65W, a 27-inch monitor about 25W, a mesh Wi-Fi node 10W, LED lighting perhaps 20W on a dark afternoon, and phone charging is a rounding error. Call it 120–150W continuous, or roughly 1–1.2kWh across an eight-hour day. A desktop workstation with twin monitors doubles that; video calls add little.
Then winter heating arrives and rewrites the budget. Even a well-insulated 3m × 3m garden room wants 500–1,000W of heating for much of a January day — 4–8kWh, four to eight times the entire IT load. No realistic shed-roof array delivers that in December, when UK panels yield barely 0.6–0.8kWh per day per kW installed. Every honest garden office design therefore makes a decision about heat first and electronics second.
Route one: off-grid, for part-time and fair-weather use
If the office is used two or three days a week, or mostly outside deep winter, an off-grid system is clean and quick. A sensible spec is 800W–1.2kW of panel, a 24V/200Ah LiFePO4 battery (roughly 5kWh usable), a 40A MPPT controller, and a 2kW pure sine wave inverter — £1,500–£2,500 in 2026 component prices, self-installed where you are comfortable with the low-voltage rules. That setup runs the IT load indefinitely from March to October and survives winter weeks with a small backup heater plan: many off-grid office owners burn a few hours of a 500W panel heater on bright days and accept a flask-and-fingerless-gloves approach on the darkest ones.
The discipline that makes off-grid offices work is separating heat from electricity wherever possible. Insulation beyond Building Regs minimums repays itself in battery capacity you no longer need; so does a heated seat pad (40W) doing the job people reflexively assign to a 2kW fan heater.
Route two: grid-tied, for the five-day-a-week office
For daily, year-round use the better answer is usually mains power to the building plus solar feeding the house — not solar pretending to be the grid. Run an armoured cable spur (a notifiable job for a registered electrician, typically £600–£1,200 including the trench), then put 2–3kWp of panels on the garden building or house roof through an MCS-certified installer. The panels offset the office's annual consumption across the year, surplus summer generation earns Smart Export Guarantee payments, and the 0% VAT rate on domestic installations until 31 March 2027 takes a meaningful slice off the invoice.
The combination costs more up front — £3,000–£5,500 all in — but it removes every winter compromise: heating, kettle, and a workstation all just work, while the array quietly pays the running cost back. Annual generation from 3kWp in the UK is around 2,550kWh; an office consuming 1,500kWh a year leaves a healthy exported surplus. Detailed figures, including the payback arithmetic, sit on the costs page.
Which route are you?
Use off-grid if: occupancy is part-time, you can be flexible on the coldest days, there is no easy cable route, or you want the office to be genuinely independent of the house. Use grid-tied if: you work from it five days a week, heat electrically through winter, are likely to add equipment over time, or simply want SEG income and zero-rated installation. If you are between the two — a common place to be — send your weekly pattern through the contact form and we will give you a straight recommendation. The kit guide covers the underlying architectures in more depth.