Solar panel direction, angle and shade in Melbourne

Which direction should solar panels face in Melbourne?

North, if you can. CSIRO notes that the best alignment for a year’s output faces the equator, which here means north. PVGIS, the European Commission’s solar model, puts a 6.6 kW system on a 20° north roof in Mount Waverley, Melbourne at 9,368 kWh a year. North-east and north-west lose only about 4%, east and west about 13 to 14%, and south about 31%. The table runs every direction at three roof pitches.

Two patterns stand out. The gap is a winter one: in June, east and west make about 36 to 37% less than north, but in December east makes 1,090 kWh to north’s 1,086. And the flatter the roof, the less direction matters: on a 10° pitch, east or west lose about 8% against north; on a 30° pitch, 17 to 18%. Laid flat, every direction makes the same 8,293 kWh.

Estimate output for your roof

What is the best angle for solar panels in Melbourne?

Facing north, about 35° from horizontal makes the most power over a year: PVGIS’s own optimiser picks 35° for Mount Waverley, Melbourne. The top of the curve is flat, though. Any tilt from 20° to 45° makes at least 97% of the best, and laid flat panels still make 86%. That is why panels on a pitched roof usually sit flush with it. CSIRO’s guide “Solar photovoltaics: optimising performance” says special tilt racking can reach the optimum, “but the small gain in output may not compensate for the aesthetic and economic costs of the racking”.

Should panels be steeper for winter?

Steeper panels face the low winter sun more squarely. At 60° a north array makes 35% more in June than at 20°, but 30% less in December and 6% less over the year. Unless winter output is what you need most, the roof’s own pitch, or a modest tilt on a flat roof, is the better trade.

West or east-west roofs, time-of-use tariffs and the free midday hours

Since 1 October 2026, Victorian retailers with 1,000 or more household customers must offer the Midday Power Saver: grid power is free from 11 am to 2 pm, up to 24 kWh a day, with a solar soak rate from 2 pm to 4 pm and a peak rate from 4 pm to 9 pm. The Victorian Default Offer’s time-of-use tariff has the same 4 pm to 9 pm peak. On a plan like that, solar made in the free hours saves little, while solar made before 11 am or after 2 pm replaces power you would pay for, most of all in the 4 pm to 9 pm peak.

So we summed PVGIS’s hourly model of 2005 to 2023 into the Midday Power Saver’s periods, on Melbourne clock time (the free hours don’t move with daylight saving).

• West makes 1,312 kWh a year less than north, but 635 kWh more in the 4 pm to 9 pm peak.
• North-west gives up only 370 kWh a year and gains 483 kWh in the peak. CSIRO gives this as its example of a roof chosen to produce “the most power later in the day”, when people are home.
• East makes 37% of its power before 11 am, which suits a household that runs its appliances in the morning.
• Half east, half west makes about 86% of north’s yearly output, much the same in the peak (1,170 kWh against 1,145) and less in every other period. Its case is roof space, not timing.

A west roof comes out ahead only if the household uses that late power itself: Solar Victoria says homes with solar panels alone use around 25% of what they generate, and what they export earns only the feed-in tariff. A battery does the same job from any roof, by storing midday solar for the evening.

Free midday power with solar

What exported solar earns

Shade: what it costs and how design works around it

Panels are wired in series, so shade on part of the array costs more than its share. CSIRO puts it plainly: “compromising the output of one module or even one cell can affect the performance of the entire string.” Modern panels have bypass diodes that “limit the risk of overheating, but shading can still severely limit output”. And shade “is often more of a problem in winter, when the sun stays lower in the sky”: a tree or a neighbour’s second storey that misses the roof in summer can cover it in June.

A good design works around shade in four ways:

• Map it across the year. The SAA Technical Requirements (version 1.9, February 2026) require a site-specific design that covers all shading, orientation and tilt. CSIRO says a competent installer should be able to describe a system’s shading risk in detail, using sky images and the sun’s path for difficult sites.
• Leave the shaded spot empty. CSIRO says partial shading “must be avoided where possible”, so panels go where the sun reaches them for most of the day, and a heavily shaded corner stays bare.
• Separate the strings. Each roof face, or a shaded section, goes on its own maximum power point tracker (MPPT); every inverter on our solar inverters page has at least two.
• Panel-level electronics. Microinverters or optimisers let each panel give its own best output, which helps most where shade crosses part of the array for hours.

Look, don’t touch: you can check shade from the ground. Note where shadows fall on the roof in the morning, at midday and in the afternoon, ideally in winter, and tell your installer. Don’t climb onto the roof to look.

Microinverters for shaded roofs

Cloudy days, winter and night in Melbourne

Cloud cuts output but rarely stops it: as CSIRO says, a system “can continue to produce some power when the sun is shaded by clouds”. To show how much, we added up PVGIS’s hourly model of a north-facing 6.6 kW system in Melbourne day by day, for 2005 to 2023.

A dull December day still beats an average June one, and an average December day makes about 2.4 times an average June day. Winter brings shorter days and a lower sun as well as cloud, which is why direction and tilt matter most then. Cold itself doesn’t hurt: CSIRO notes that output falls slightly as panels heat up, and that they run cooler in winter.

At night panels make nothing. A battery stores daytime solar for the evening: Solar Victoria says homes with a battery use around 50 to 60% of their solar, against 25% without.

Solar batteries for the evening

Tile, metal and flat roofs: how panels are fixed

Most roofs take solar. What changes is the fixing, and the SAA Technical Requirements (version 1.9, February 2026) make the designer responsible for a mounting frame installed to comply with the wind standard, AS/NZS 1170.2. Here is what a good installer does on each kind of roof.

Look, don’t touch: you can tell your roof type from the ground or a photo. Never walk on a roof to check: Solar Victoria lists brittle roof sheeting, skylights and corroded metal among the fall hazards even trained installers plan around.

Tile roofs

Stainless steel tile hooks screw to the timber under the tiles and come out between them to carry the rails (one racking maker’s tile interface is specified for a tile roof with timber purlins). The SAA rules require tiles to sit flat again after the brackets go in, so they keep out the weather as before, even if the underside of a tile has to be ground, and they require a collar flashing where the cable passes through a tile or steel roof.

Metal roofs: Klip-Lok and Trimdek

Lysaght’s Klip-Lok is clip-fixed: hidden clips hold the sheets, and it suits near-flat and low-pitched roofs. Racking for these concealed-fix roofs can use clip-on clamps that need no holes through the roof. Trimdek is pierce-fixed, with its screws through the sheet. On screw-fixed roofs the racking does the same: each bracket screws through into the purlin below, over a rubber seal (2 mm EPDM on one metal-roof bracket). The racking maker’s guide also makes the installer responsible for keeping the roof watertight, choosing the right flashing and avoiding corrosion between different metals.

Flat roofs and tilt frames

Panels laid flat make about 86% of the best tilt’s output, and CSIRO says rain cleans panels reasonably well only above about 5°. So flat roofs usually get tilt frames: one racking maker’s adjustable legs set panels between 10° and 60°. Facing north, a 10° tilt lifts output to 93% of the best and 20° to 98%. A frame is part of the mounting, so it is engineered for wind like any other.

Wind loads

One racking maker’s installation guide says its parts meet AS/NZS 1170.2:2021 when installed as the guide sets out. The installer works out the wind region and the terrain category (suburban housing is category 3), and the maker’s certificate sets how far apart the fixings may be. For a site outside terrain categories 2, 2.5 and 3, that maker issues a project-specific engineering certificate. The installer also checks that the rafters or purlins can carry the array.

The panels set limits too. Canadian Solar’s manual wants clamps at four or more points on two opposite sides, inside the ranges its tables set for the load, and REC’s wants a clamp in each of four marked zones on the frame, so the rails must suit the panel as well as the roof. Clamps outside those zones are one of the install faults an inspection looks for.

Asbestos cement roofs

Asbestos was common in Australian building from the 1940s to the late 1980s, and guidance for solar installers from Solar Victoria and WorkSafe Victoria says a home built or renovated before 1990 is likely to contain some. Drilling, grinding or cutting it releases fibres, and the guidance puts removal first, by a licensed asbestos removalist. Fixing panels means drilling into the roof, so an asbestos cement roof, Super Six sheeting included, needs re-roofing before solar: the removalist takes the old sheets off, then the panels go on the new roof.

Is your roof ready? Age, leaks and re-roofing first

Solar Victoria expects panels to last more than 25 years, so the roof under them should too. If it will need replacing soon, re-roof first, or the panels have to come down and go back up (removing panels for a re-roof). On steel, BlueScope asks for corroded roofing screws under the array to be replaced first. The SAA rules require a collar flashing where the cable passes through a tile or steel roof, and a later leak at a bracket or cable entry is a question for the installer’s workmanship warranty.

A skillion roof is one plane, so its slope sets the panels’ direction. On one that slopes south at 10°, flush panels lose about 17% against north; tilt frames turned north win most of that back. On metal sheeting, the metal-roof fixings above apply.

Coastal homes and steel roofs: corrosion

BlueScope’s TB-36 bulletin says stainless steel, lead, brass and copper should not touch COLORBOND or ZINCALUME steel, or connect to it electrically, conductive washers and seals included. The roof under the panels also misses the rain’s rinse, so it asks for a gap of commonly more than 75 mm above the ribs and a fresh-water rinse of that strip at least every 3 months in coastal or industrial areas (6 elsewhere): a job for a professional.

Near the sea, Canadian Solar’s Australian manual sets panel rules by distance from the high-tide line: up to 20 m, Type II anti-corrosion panels must be used; 20 to 100 m, Type I anti-corrosion panels must be used; 100 to 500 m, Type I anti-corrosion panels are recommended; more than 500 m, the general instructions apply. That matters for homes close to the water in bayside suburbs, on the Mornington Peninsula and the Bellarine, and in Geelong and Warrnambool. Ask for the model’s salt mist rating and check where the inverter can go.

No suitable roof? Ground mounts and carports

If the house roof is shaded, faces south or is too small, panels can go on a ground frame or a carport. STCs still apply: the Clean Energy Regulator’s STC paperwork records a system as “Building or structure” or “Ground mounted or free standing”. What changes:

• Wind. The frame is engineered to AS/NZS 1170.2 for its own site.
• Permits. Victoria’s Building Regulations exempt a freestanding carport from a building permit only up to 10 m² of floor area (as the City of Monash and the building regulator’s practice note explain), and a 6.6 kW array of the panels in our panel guide covers about 28 m². So expect a solar carport to need a building permit: a building surveyor or your council can confirm, and say whether a planning permit applies too.
• Cabling. The cable to the switchboard, which may run underground, is a licensed electrician’s job, to the wiring rules (AS/NZS 3000) that Energy Safe Victoria lists for solar.

What a good design for your roof shows

Direction, tilt, shade and roof type all end up in one place: the system design behind your quote. Under the SAA Technical Requirements (version 1.9, February 2026), the system designer is responsible for:

1. A site-specific design that covers all shading, the orientation and the tilt.
2. An estimate of the average daily output in kWh for each month.
3. An array that fits the roof space.
4. A mounting frame installed to comply with the wind standard, AS/NZS 1170.2.

On top of that, ask how the panels will be fixed to your roof type, whether the wind certificate covers your site, and, for a home built before 1990, whether the roof has been checked for asbestos. Ask for the same in any solar quote, ours included.

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Panel direction and angle: your questions