Tiny home solar: how many panels do you need?
Updated 4 Nov 2026. Solar sizing comes down to three numbers: how much energy you use each day, how many peak sun hours you get, and your system losses.
1. The formula
Panel watts needed ≈ daily Wh ÷ peak sun hours ÷ 0.75. The 0.75 allows roughly 25% for losses from heat, wiring, the charge controller, the battery and the inverter. Peak sun hours are often about 2 to 3 in winter at high latitudes and about 5 to 6 in sunny summer climates. Check local solar data for your site.
2. Worked example (estimate)
| Daily use | Summer (5 sun hours) | Winter (2.5 sun hours) |
|---|---|---|
| 2 kWh | ~530 W (2 × 300 W panels) | ~1,070 W (about 3 to 4 panels) |
| 4 kWh | ~1,070 W | ~2,130 W |
| 6 kWh | ~1,600 W | ~3,200 W |
| 10 kWh | ~2,670 W | ~5,330 W |
Example: 4,000 Wh ÷ 2.5 h ÷ 0.75 ≈ 2,130 W, or about 5 × 430 W panels, to cover a typical winter day. Sizing for summer only means relying on a generator or shore power in winter.
All figures on this page are estimates for planning. Real use depends on climate, appliances and habits.
3. Practical tips
- Tilt and orientation: face the equator (north in the Southern Hemisphere, south in the Northern Hemisphere). A steeper tilt helps in winter.
- Shading: even partial shade cuts output sharply. Mount panels clear of trees.
- MPPT controllers harvest more than PWM. See MPPT vs PWM.
- Roof vs ground mount: a tiny roof often fits only about 1 to 2 kW, so a ground array can add more.
- Portable panels plus a power station suit small or mobile setups. See How many solar panels?, solar blankets vs suitcase panels and AC vs solar charging speed.
Tiny home rules by country (summary)
General information only, checked against official sources on 4 Nov 2026. Rules change and vary by state, province and council, so always confirm locally.
| Country / region | Key rule | Official source |
|---|---|---|
| New Zealand | A tiny house that is immovable and lived in long term is generally a building needing consent. Since 15 Jan 2026, a new single-storey standalone dwelling up to 70 m² can be built without building consent if it meets the exemption conditions, uses licensed professionals, and you get a PIM first and notify council at the end. | MBIE tiny houses · MBIE granny flat exemption |
| Australia (NSW) | A tiny house on wheels is usually a moveable dwelling/caravan. Approval exemptions are limited (for example short stays of up to 2 days in a row and 60 days a year). Otherwise expect a development application and Local Government Act s68 approval. | NSW Moveable Dwellings Regulation 2021 |
| Australia (Victoria) | A fixed "small second dwelling" up to 60 m² on a lot with an existing home often needs no planning permit, but a building permit is always required. | Victorian Building Authority |
| United States | Permanently occupied tiny houses fall under the International Residential Code (Appendix AQ, 400 sq ft or less, where adopted locally). Wheeled units built as Park Model RVs (ANSI A119.5, up to 400 sq ft) are for recreational or seasonal use, and local zoning decides where they can stay. | ICC tiny house white paper · RVIA |
| Canada | Year-round tiny homes must meet the local building code and zoning. RV-certified units (CSA Z240 RV) are not for permanent residence. | City of Calgary example |
| United Kingdom | A unit can legally be a "caravan" if movable and within 20 m × 6.8 m (3.05 m internal height). Living in one as a separate home usually needs planning permission. Ancillary use by the same household in a house's garden may not. | Caravan Sites Act 1968 s13 · GOV.UK caravan definition |
| France | A tiny house without foundations, quickly removable and used as a main home at least 8 months a year can count as a "résidence démontable", which still needs a planning declaration or permit. | Ordre des architectes (cites Code de l'urbanisme R111-51) |
| Germany | A permanently lived-in tiny house, even on wheels, is generally treated as a building that needs a permit under the state building code. | City of Munich guide (PDF) |
| Japan | A trailer house counts as a vehicle rather than a building only if it can be moved at any time and is legal on public roads, with no fixed stairs and only quick-disconnect utilities. Otherwise it needs building approval. | Hamamatsu City (Japanese) |
Electrical work: in most countries, mains wiring and grid-connected solar or batteries must be installed and certified by a licensed electrician. NZ example: WorkSafe DIY solar.
FAQ
How many solar panels does a tiny home need?
Divide daily Wh by peak sun hours, then by 0.75 for losses. A 4 kWh/day home in a 2.5 sun-hour winter needs about 2,100 W, or about 5 × 430 W panels.
Roof or ground mount?
A tiny roof often fits only about 1 to 2 kW. A ground mount adds space and lets you set the best tilt.
Do I need permission for solar?
Often not for the panels themselves, but electrical connection rules apply. See the rules table above.
Where to buy
Portable power and solar kits: Power stations at ALLPOWERS (US & CA) (affiliate link).
Home batteries, inverters and solar panels: we're still waiting on approval from more brands. Until then, use a reputable local installer.
Tiny home power guides: Overview · Solar · Batteries · Power supply · EV & e-bike charging