How Many Solar Panels Does It Take to Run a Shed?

The method in four lines

One: list every load, its wattage, and its daily hours; multiply and total to get daily watt-hours. Two: decide your worst month of real use — December for year-round sheds, perhaps March–October for fair-weather hobbies. Three: divide daily watt-hours by that month's yield per panel watt — in the UK, roughly 0.6–0.8Wh per panel watt per day in December, 2Wh in March or October, 4Wh+ in June — and add 30% for charging losses and cloudy-run margin. Four: size the battery for two to three days of autonomy at your chemistry's usable depth of discharge. That is the entire discipline; everything else is shopping.

Loadout one: the hobby shed

Two LED battens (10W each, two hours most evenings), a USB charging point (10W, two hours), and a small Bluetooth speaker. Daily total: 60Wh, used year-round. December sizing: 60Wh ÷ 0.7Wh-per-watt × 1.3 margin ≈ 110W of panel. A single 100W panel is marginally under; a 150W panel (about £15 more) clears it comfortably and that is the correct buy. Battery: 180Wh of autonomy-doubled storage means even a modest 50Ah AGM (≈300Wh usable) is generous — the cheapest tier on the battery page genuinely suffices here. Total spend lands near £180.

Loadout two: the bike workshop

Four LED battens (40W total, two hours), a 60W track-pump compressor used briefly, cordless tool charging (65W charger, two hours), a radio (10W, three hours), and a 40W heated dryer pad for wet kit in winter (two hours). Daily total: about 400Wh, heavily winter-weighted — which is the trap, because the wet-kit season is the no-sun season. December sizing: 400Wh ÷ 0.7 × 1.3 ≈ 740W of panel. In practice we would spec 2 × 350W residential-size panels if the roof takes them, or accept 400–500W and plan for the dryer pad to skip the darkest fortnight. This is the honest trade-off sizing always surfaces: the last 20% of winter capability costs more than the first 80%.

Battery: 800–1,200Wh usable wants a 12V/100Ah LiFePO4 (≈1,100Wh usable). At 24V the same capacity halves the system current — at 740W of panel, that is the better architecture, as explained in the kit guide. Budget: £1,100–£1,400 self-installed.

Loadout three: the craft studio

A sewing machine (90W, three hours), an overlocker (120W, one hour), good task lighting (60W total, four hours), an iron — the budget-killer — at 1,800W for twenty minutes, and a laptop (50W, three hours). Daily total: roughly 1,180Wh, March-to-November use. Sizing on a 2Wh shoulder-month figure: 1,180 ÷ 2 × 1.3 ≈ 770W of panel — two 400W panels. The iron also dictates the inverter: 1,800W continuous demands a 2,500–3,000W pure sine unit, which at 12V would mean 250A of battery current. This loadout is 24V by force, not preference, and the 100Ah/24V lithium battery (≈2,100Wh usable) covers a full day with margin. Budget: £1,600–£1,900 — and the iron alone accounts for perhaps £350 of it. Swap to a 30W mini craft press and the whole system drops a tier, which is the kind of substitution worth knowing about before buying, not after.

What the three examples share

In every case the panel count came out higher than the kit listings suggest, because listings quote June and sheds get used in December. And in every case one or two specific appliances set the architecture — the dryer pad, the iron — not the total. Run your own list before spending anything; if you would like a second pair of eyes on it, send it through the contact form and we will size it properly. Costs for every tier mentioned here are itemised on the costs page.