Which way should solar panels face in Darwin?

Panels facing (15° tilt)	Per kW, per year	6.6 kW system	vs north	Summer / winter per kW
North	1,543 kWh	10,186 kWh	100%	309 / 434 kWh
East	1,471 kWh	9,706 kWh	95%	329 / 373 kWh
West	1,439 kWh	9,500 kWh	93%	319 / 367 kWh
South	1,356 kWh	8,948 kWh	88%	340 / 299 kWh

Modelled AC output from a typical weather year for central Darwin (2005–2023 PVGIS data), 14% system losses plus inverter losses, no shading.

Is east or west better in Darwin?

East, by a little. In Darwin east facing panels make about 95% of a north facing roof and west facing panels about 93%. In Darwin's typical weather year the mornings are sunnier than the afternoons, so the east side comes out ahead.

On a clear summer day in Darwin, north facing panels peak around 13:00, east facing panels around 12:00 and west facing panels around 13:50 (local standard time, so add an hour during daylight saving where it applies). If you use most of your power in the afternoon, or you want a battery full before the evening peak, west facing panels line up with that better than the annual numbers suggest.

Are south facing panels worth it in Darwin?

Usually, yes. South facing panels at 15° make about 1,360 kWh per kW a year in Darwin, which is 88% of the same panels facing north. At the Solar Choice price index figure of $0.88 to $0.95 per watt installed, that energy works out to roughly 2.8c to 3.0c per kWh over 25 years. That is around what retailers typically pay for exported solar, and a small fraction of what grid power costs, so extra panels on the south side generally pay their way.

In summer the sun rises and sets well to the south of east and west, and in Darwin it climbs almost straight overhead at midday. So south facing panels actually make slightly more than north facing ones from December to February, then drop to about 69% of north in winter.

Flatter is better on a south facing roof. At 5° a south facing layout in Darwin makes about 94% of a north facing system at 15°. Check that your inverter has room for the extra panels and how much your network lets you export before you commit.

What is the best tilt for solar panels in Darwin?

Facing north, the tilt that makes the most energy over a year in Darwin is about 19°, but it makes almost no difference compared with a 15° roof. A common 22.5° pitch gets 100% of the best possible. In other words, use the roof pitch you have. Tilt frames on a pitched roof almost never pay for themselves. The Solar Panel Angle Calculator shows the full picture for any direction and tilt.

How much does solar output change through the year in Darwin?

Less than you might think, and the other way round to the southern capitals. North facing panels in Darwin make about 434 kWh per kW over winter, the dry season, and about 309 kWh over summer, the wet season. Cloud does more to Darwin solar than the sun angle does.

Where do these numbers come from?

They are modelled with the same engine as the Solar Panel Orientation Comparison, using a typical meteorological year from PVGIS, the solar database run by the European Commission Joint Research Centre. Each hour of the year is worked through for every panel direction, then reduced for panel heat, 14% system losses and a 96% efficient inverter. Your own roof will differ with shading, panel brand and exact location, so treat these as a guide rather than a quote.

Other cities

See the same comparison for Sydney, Melbourne, Brisbane, Perth, Adelaide, Canberra and Hobart, or read which way solar panels should face in Australia for the national picture. Outside Australia, there are city by city results for the UK and the US.

Common questions