How Much Rooftop Solar Power Can Be Installed In Australia?

Rooftop solar power in Australia

Ever wondered how much rooftop solar panel capacity could in theory be installed in Australia given the rooftop real estate available in this country? Here’s an answer.

A new report authored by the Institute for Sustainable Futures (ISF), the School of Photovoltaic and Renewable Energy Engineering (SPREE) at UNSW and the Australian PV Institute (APVI) puts a number on it:

179 gigawatts

That’s around twenty times more than the total capacity of all small-scale solar power systems currently installed in Australia (~8.6GW – Clean Energy Regulator, April 2019). There are also 100kW+ rooftop commercial solar systems that have popped up around the place and a bunch of non-rooftop solar farms. APVI figures indicate that as at the end of September last year, there was 10.1GW of solar PV capacity installed across Australia (all types).

A Lot Of Solar Panels

How many solar panels is 179 gigawatts? Based on a module capacity of 300 watts, around 596.6 million panels – approximately 24 solar panels for each woman, man and child in Australia (and  ~ 7 kilowatts per capita).

So, where is the potential and what’s the breakdown? More than half is in residential zones:

Zone PV Potential (GW) Annual Energy Output (GWh)
Residential 96.0 1,30,153
Rural / Primary Production 33.9 46,680
Industrial /Utilities 19.0 26,464
Commercial /Business 9.3 12,601
Special Use 6.7 9,357
Mixed Use 4.0 5,584
Community Use 3.9 5,371
Unknown 2.2 3,052
Conservation /National Park 2.1 2,884
Recreational /Open Space 1.7 2,346
Transport /Infrastructure 0.6 774

There’s a number missing in the report’s table at the time of publishing for Annual Energy Output for the Residential zone classification – perhaps it should read 1,300,153 or 1,301,530 – in any event, it’s a lot.

179 gigawatts of rooftop solar could generate (very) roughly around  261,340 gigawatt hours of electricity a year – or 261.34 terawatt-hours (the report pegs it at 245 terawatt-hours). That’s more than current annual consumption in the NEM plus Western Australia’s SWIS1 says the report, which is just under 220 TWh  per year.

Realising The Potential Of Rooftop PV

Just because you might be able to do something, it doesn’t mean you should. The study report isn’t suggesting Australia should (or could) source all its electricity from rooftop solar panels and of course there are caveats and assumptions relating to the figures it notes says APVI. But these initial findings serve to indicate we’ve really only just begun to tap into the potential of rooftop PV in this country.

The full report: How Much Rooftop Solar Can Be Installed In Australia?, which includes methodology, can be downloaded here..

On a related note, APVI released a report last year detailing the potential for rooftop solar in the Central Business Districts (CBDs) of each Australian capital city.


  1. The NEM – National Electricity Market – consists of Queensland, New South Wales, ACT, Victoria, Tasmania and South Australia. The SWIS is the South-West Interconnected System, which stretches from Albany in the south of WA, to Kalbarri in the north and Kalgoorlie in the east of the state. It also includes the Perth metropolitan area.
About Michael Bloch

Michael caught the solar power bug after purchasing components to cobble together a small off-grid PV system in 2008. He's been reporting on Australian and international solar energy news ever since.


  1. How much of the excess could actually be used. meaning how would it be delivered backwards through the system to be able to be used.
    Meaning the more people that have it, the further it has to travel backwards to be able to be used somewhere.
    So if everyone in a suburb had solar, all the exports from them would have to travel backwards through and then forwards through transformers to be re-used.
    Given that inverters are only sending out around 230volt power, its going to be hard to get it to travel any distance.

    • Denis Cartledge says

      “So if everyone in a suburb had solar…”

      They wont! Using the “law of averages” (or whatever “law” one chooses, no suburb will ever be saturated with ……, choose you item.

      What it does mean thought, and I am no Electrical Engineer, is that there must be a certain installation % whereby all or most of the town/feeder area is being locally supplied during the day. So the draw-down from the Grid becomes minimal, as does the distance transmission, hence costs of and losses from the Poles and Wires. This has to reduce those overheads.

      Admittedly there is still the issue of amortising the capital costs of the Grid.

      However, doesn’t “Market forces” come into play here?

      If an Industry Model is no longer viable, shouldn’t it be just let go?

      Horse transport industry 100 years ago.
      Coal Gas manufacture and supply to residential and business 50 years ago
      Motor vehicle manufacturing industry 5 years ago.

  2. Anthony Willis says

    I have been considering expanding my existing system, but I am put off by the rumor that energy companies are considering charging solar users for exporting power back to the grid.

    • Ronald Brakels says

      Fortunately, you won’t be charged for sending solar electricity into the grid. (This may be possible for short periods with unusual plans that pay you the wholesale price for electricity, but you will still be paid for excess solar power sent into the grid overall.)

      • The rumblings are from the Distributors such as Powercor (who are often “Gentailers as well ): they claim managing the poles and wire infrastructure needs additional investment for household solar to be accommodated. ( There are already grid restrictions in many areas) Their costs appear on our bills as service charges and whilst regulated (in Victoria anyway) the scope is there to further erode home solar cost savings.

        • Denis Cartledge says

          My take on them trying to emulate Council S&W charges, if access goes past the property, you pay an charge, would be that many of us “oldies” would refuse to pay that charge and instead say “take so Court”.

          We would then represent ourselves and clog up the Courts for years.

          The other “threat” that can be used in that case, that of bad Credit Ratings, is also a hollow log (bad metaphor, but who cares). I am 71, almost without a Mortgage, most of my income is independent of govt and am never going to borrow again.

          How hollow (a threat) is that? 😉

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