Solar panel sizes for Melbourne roofs: how big, how heavy and how many watts

What size is a solar panel in Australia?

There is no single standard size: each maker sets its own, and the ranges on our list sit within 8 cm of each other in length and width. Going by their datasheets, a typical panel measures:

• Length: 1,722 to 1,800 mm, the side that runs up the roof when panels sit in portrait.
• Width: 1,134 to 1,205 mm. Four of the five ranges are 1,134 mm wide.
• Depth: 30 to 35 mm, the thickness of the frame.
• Area: 2.0 to 2.1 m² for each panel.
• Weight: 22 to 25 kg.

Longer panels exist. Canadian Solar’s Australian datasheets also list panels 1,961 mm and 2,382 mm long at the same 1,134 mm width, rated up to 540 W and 645 W. They are one way to a 500 W+ panel: a bigger panel rather than a more efficient one.

Dimensions and weight of the panels on our list

Every figure below comes from the maker’s own datasheet, checked October 2026. Our previous site listed these brands; which we fit today is being confirmed, and your quote names the exact model.

JA Solar was also in our previous range. We couldn’t read its current Australian datasheet from JA Solar’s own site, so its size isn’t listed; your quote confirms the model.

Compare the panels on our list

Solar panel wattage: what 440 W, 475 W and 500 W+ mean

A panel’s wattage is its output under Standard Test Conditions (STC): 1,000 W of light on each square metre, cells at 25°C and a light spectrum of AM 1.5. It is a laboratory figure for comparing panels, and a roof rarely sees those conditions. Canadian Solar’s datasheet shows the gap: its 475 W panel makes 359 W in the warmer, dimmer NMOT test (800 W per m², 20°C air, a 1 m/s breeze), about 76% of the label.

One panel size can carry several ratings. Canadian Solar sells the CS6.2-48TD at seven ratings from 445 to 475 W, all 1,762 × 1,134 mm. The higher ratings are simply the more efficient panels of the same size: 22.3% at 445 W, 23.8% at 475 W. Each of its ratings carries a tolerance of −5 W to +10 W.

• 440 W: the rating of a panel about 1.7 m by 1.1 m, such as the Phono Solar Helios.
• 475 W: the top rating in the ranges on our list (Canadian Solar TOPHiKu6 and Phono Solar Quasar), from panels much the same size as a 440 W one but more efficient.
• 500 W and up: none of the ranges on our list goes this high. Canadian Solar’s 520 to 540 W panel is 1,961 mm long and its 570 to 645 W panel 2,382 mm, so most of their extra watts come from extra length. AIKO’s Neostar 3P54 gets to 500 W at the usual 1,762 × 1,134 mm instead, with 25.0% efficient N-type back contact cells.

Each watt of panels makes about the same energy in the same spot, so a panel’s output rises in step with its rating. The PVGIS model for a north-facing roof in Mount Waverley, Melbourne gives about 625 kWh a year from a 440 W panel, 674 kWh from a 475 W panel and 766 kWh from a 540 W panel, before any inverter limit.

Estimate your solar output

The Canadian Solar TOPHiKu6

How much do solar panels weigh, and can your roof take it?

The panels on our list weigh 22 to 25 kg each, or 10.9 to 12.5 kg for every square metre of roof they cover. A 16-panel array, the panel count of our 6.6kW package, weighs about 352 to 400 kg in all, spread over 32 to 34 m²; the rails, clamps and roof brackets add to that.

Spread out like that, the panels’ own weight comes to about 107 to 123 Pa (pascals). The panels themselves are rated for far larger loads: Canadian Solar’s datasheet gives the CS6.2-48TD a wind load of up to 2,400 Pa and a snow load of up to 5,400 Pa, and points to its installation manual for the details. Those are the panel’s ratings, not your roof’s.

Clause 3.3.1 of the SAA Technical Requirements (version 1.9, February 2026) makes the system designer ensure that the array fits the available roof space and that the mounting frame installation complies with AS/NZS 1170.2, Standards Australia’s wind actions standard (Structural design actions – Part 2: Wind actions). Clause 5.1.1 asks for enough clearance under the array for the roof to shed leaves and debris.

If your roof is old, damaged or sagging, or its tiles are brittle, say so when you ask for a quote: we look at the roof at the free inspection before we design the array.

Bigger panels or more efficient panels?

A panel’s watts per square metre is its efficiency at work: at 1,000 W of test light per m², a 23.8% efficient panel rates about 238 W for each square metre. A bigger panel with the same efficiency gives more watts per panel, but not more watts from the same roof.

On 32 m² of roof, the ranges on our list add up to about 7.2 to 7.6 kW. The 645 W panel fits about 7.6 kW into the same space, because its watts per m² are much the same: fewer, heavier panels rather than more power from the roof. AIKO’s 500 W panel, at 250 W per m², fits about 8.0 kW: more efficient cells are what add power on the same roof. A long panel can also leave more of a small or broken-up roof unused. So when roof space is tight, compare watts per m²; when it isn’t, compare price and warranty.

Solar panel efficiency explained

How much roof does each panel take up?

Allow about 2.0 to 2.1 m² of roof for each panel: our 6.6kW package uses 16 panels, about 32 to 34 m² before the gaps and the clearances from roof edges, and our packages run from 6.6 kW (16 panels) to 28 kW (68 panels). The system size you need depends on your power use, your roof and your network’s limits, and the sizing guide works it through. Direction matters too: in the PVGIS model an east-facing roof makes about 13% less a year than a north-facing one, and a west-facing roof about 14% less.

What size solar system you need

Which way your panels should face

The 6.6kW system in detail

Solar panel sizes: your questions