Not every off-grid power need is about the house. Plenty of rural NSW properties have a shed, workshop, machinery bay or converted outbuilding that needs its own power — sometimes because it's too far from the house to run cable economically, sometimes because the owner would rather keep workshop loads (welders, compressors, power tools) completely separate. A standalone shed system is a genuinely different design problem, and the key insight is this: a shed using just 3–4 kWh a day can still need a 5kW-plus inverter if it runs a welder, because surge — not daily energy — sets the size.
Running underground or overhead cable from a house system to a distant shed isn't cheap — trenching, cable sizing for voltage drop over distance, and conduit work can rival the cost of just putting solar and a small battery on the shed itself, especially beyond 50–80 metres. Beyond cost, a standalone system means workshop loads never compete with household loads for battery capacity, and a welder tripping a circuit doesn't touch the lights in the house. The trade-off is that a standalone shed system needs its own sizing discipline — you can't quietly borrow capacity from the house battery bank when running a compressor and an angle grinder at once.
Start with the surge, not the average. As with pumps, the peak instantaneous demand — starting a compressor, firing up a welder — usually dictates inverter size well before daily energy use does. A shed that "only" uses 3–4kWh a day might still need a 5kW-plus inverter if it runs welding equipment.
Battery sizing depends on use. A shed used for occasional weekend projects has very different needs to a workshop running machinery daily. Be honest about actual use patterns — oversizing a rarely used shed wastes money, undersizing a daily-use workshop means constant frustration.
Panel placement is often easier than for a house. Shed roofs are frequently simpler, unshaded and well-oriented compared to a house roof cluttered with vents, valleys and tree shading — which can make a shed system more efficient per panel than you'd expect.
| Use | Typical setup |
|---|---|
| Lighting & small tools only | 1–2kW array, 5–10kWh battery, small inverter — covers LED lighting, charging, a bar fridge |
| General workshop with power tools | 3–5kW solar, 10–15kWh battery, 5kW+ inverter with good surge handling — including occasional welding |
| Heavy-use farm workshop / machinery bay | Larger system closer to a small home, sometimes with its own backup generator connection |
For sheds close to the house (generally under 30–50 metres), it can make more sense to extend the house system rather than build a second standalone one — it depends on cable-run cost versus duplicate equipment. For anything further out, or where load independence matters, a standalone system is usually the more sensible and durable choice.
Surge, not daily energy, sets the size. A shed using only 3-4 kWh a day can still need a 5kW-plus inverter with good surge handling if it runs a welder or air compressor, because those loads pull a large start-up surge.
For sheds within roughly 30-50 metres it can be cheaper to extend the house system. Beyond about 50-80 metres, or where you want workshop loads kept separate from the house, a standalone shed system is usually the more sensible and durable choice.
A shed or workshop system is a smaller job than a full off-grid home, but not a trivial one — surge-heavy equipment like welders and compressors catches out a lot of DIY and undersized setups. Matching the inverter and battery to your actual equipment avoids a system that looks fine on paper but frustrates you every time you switch on the welder.
Calculate your needs: planning power for a shed, workshop or machinery bay separate from the house? Get a tailored sizing recommendation through the quote wizard at blueenergysolar.com.au, or call 0421 458 217 / email sales@blueenergysolar.com.au.
