Solar Panel Placement in Australia: Orientation, Tilt & Shading Explained

The Orientation Question: Why North Isn't Always Perfect

Australia is in the Southern Hemisphere, so the sun moves across the northern sky. That means north-facing panels get the most direct sunlight throughout the day, which is why solar installers default to north-facing orientation.

But north-facing isn't always best. It depends on your roof, your shading, your electricity consumption patterns, and where you live.

North-facing panels generate maximum overall annual energy in most Australian locations. They'll produce about 95-100% of theoretical maximum. But if your roof doesn't face north, or if you've got shading on the north side that you don't have on the east or west, other orientations might actually make more sense.

The Latitude Angle Equation

The angle you tilt panels (pitch) depends on your latitude. The rule of thumb is to tilt panels at roughly the latitude angle to capture maximum winter sun while minimising summer overheating.

Sydney (latitude 34°) ideally works with about 30-35° tilt. Brisbane (27°) is better at 25-30°. Melbourne (38°) works at 35-40°. Hobart (43°) benefits from 40-45° tilt. Perth (32°) sits at about 30-35°.

But here's the thing: you're usually not choosing the tilt angle. Your roof has a fixed pitch already (maybe 22°, maybe 35°, maybe 45°). Installers work with what you've got. And honestly, the difference between perfect tilt and your actual roof pitch is maybe 5-10% of generation, which is less critical than getting the shading right.

A north-facing roof at 22° tilt generates maybe 95% of theoretical maximum. A north-facing roof at 45° tilt might generate 98% in winter but potentially suffers slightly in summer (though this is marginal). The difference is real but not massive.

When East-West Split Makes Sense

Some homes can split their panels across east and west-facing roofs. This is genuinely smart for homes with:

• Time-of-use (TOU) electricity tariffs where morning or evening power is expensive
• Hot water systems you want to heat in the morning or late afternoon
• Swimming pools with pumps you want to run morning or evening
• High afternoon consumption
• East or west-facing roof with better structural condition than north

An east-west split generates slightly less total energy than north-facing (maybe 85-90% versus 95-100%), but the generation pattern is stretched across more daylight hours. Instead of a massive midday peak that you export, you've got generation in the morning (east), midday (if you've got roof space), and afternoon (west).

For homes with battery systems, this is less relevant because batteries flatten the generation curve. But for homes without batteries looking to self-consume more, east-west splits are genuinely smart.

Assessing Shading: The Critical Variable

Shading is often the most important factor in panel placement — more important than perfect north orientation. Shade on your panels is lost generation.

Your installer should assess shading using:

Physical obstructions: Trees nearby that are growing, buildings to the north or east, hills, or terrain that blocks low-angle winter sun. A tree that's 10 meters away and currently blocks 20% of winter sun will get taller and block more in 5 years.

Seasonal variation: Winter sun is lower in the sky, so trees and buildings to the north cast longer shadows. Summer sun is high, so northern obstructions cast short shadows. A good shading analysis accounts for both.

Growth projections: Is that tree going to get taller? Are your neighbours building something that will cast shade? Consider 10-year growth when planning panel placement.

A competent installer will use shade analysis tools (most use software like PVsyst or similar that models shade over the year). They'll take photos showing obstructions and model the impact on generation.

Avoid significant shade if you can. Even partial shade on one panel in a string of panels can reduce output by 25-50% because of how series circuits work (one weak panel pulls down the whole string). If your installer isn't using shade analysis tools, that's concerning.

North with Morning Shade vs Clear East

Here's a concrete example: a home with north-facing roof that's shaded by a tree until 10am, and a clear east-facing roof.

North-facing with morning shade generates maybe 85% of theoretical north-facing potential (shade is less critical in morning). That's still a lot.

East-facing, clear, generates maybe 70-75% of theoretical north-facing.

In this case, north-facing (even with some shade) is better. But if that tree grows significantly, the equation changes.

This is why your installer should actually visit and do proper analysis, not just assume north is best.

Multi-String Designs for Partial Shade

If your roof has shading challenges, good installers use multi-string inverter designs. This means dividing panels into separate circuits (strings) so one shaded panel doesn't kill the whole system.

Microinverter systems (individual inverters on each panel) are even better for shading because shade on one panel doesn't affect others. You pay slightly more, but if shading is genuinely complex, it's worth it.

String inverters with optimisers (like SolarEdge) offer a middle ground: lower cost than microinverters but better shading performance than pure string inverter systems.

Roof Condition and Placement

Your panels need a solid roof. If your roof is nearing end-of-life, you might want to plan panel placement around areas you'll be replacing anyway, or prioritise east-facing panels that might be less damaged than north-facing.

A roofer checking your roof before solar design is smart. You don't want panels installed, then the roof leaks and you're removing and reinstalling panels.

Wind Loading and Structural Concerns

Australia gets genuine wind. Panels create wind load on your roof, which needs to be assessed. Coastal areas are more exposed than inland. Exposed hilltops are more exposed than valleys.

Your installer should calculate wind loading based on your location's wind region (AS/NZS 1170.2) and design racking systems accordingly.

Roof structural capacity also matters. Old Colorbond roofs can sometimes be reinforced for panels. Some tile roofs need additional bracing. This is all part of proper design, not an afterthought.

Temperature and Ventilation

Panels in direct sun get hot. Temperature coefficient (efficiency loss per degree above 25°C) means hot panels generate less than cool panels. This is Australian reality — panels regularly hit 65-70°C on summer days.

You can't fight the physics, but proper installation with good airflow under panels helps marginally. Panels mounted with space underneath (rather than flat against the roof) stay slightly cooler.

This is a minor factor compared to shade, orientation, and tilt, but it's worth knowing that Australian heat reduces panel efficiency measurably.

The Final Placement Decision

Your installer will bring all this together: roof condition, orientation, tilt angle, shading analysis, wind loading, and space available. They'll spec a system designed for your specific roof and situation.

The best placement for your home depends on your specific circumstances. For most Australian homes, north-facing (or close to north) with minimal shade and proper tilt is ideal.

But if your roof doesn't face north, or if shading is complex, alternative orientations or designs might actually be better. That's why a good site assessment and analysis matters more than blindly following the "north-facing is best" rule.

Learn about panel sizing and system design

Explore inverter options for complex roofs

Check how to choose a quality installer