Rooftop solar marches on as large scale renewables stranded | RenewEconomy

Rooftop solar marches on as large scale renewables stranded

New data highlights how policy certainty affects two big renewable energy markets in Australia: Rooftop solar is growing, large scale renewables at standstill.


New data from the renewable energy industry highlights just what impact policy certainty – or the lack of it – is having on the small and large scale markets.

Rooftop solar – largely funded by the balance sheets of Australian households and businesses – continues to surge ahead. That’s helped by the fact that federal incentives – which are paid upfront – are locked in by legislation.

This graph below shows the trend in small-scale rooftop solar systems, both residential (below 10kW and in green), and commercial scale systems (between 10kW and 100kW and in blue) over the past year. After sharp falls caused by the winding back of various staste-based feed in tariffs, the deployment of solar by homes and  businesses has steadied, and is now growing solidly.

According to Green Energy Markets, more than 155,000 small-scale solar systems have been added across Australia in 2014, an average of more than 15,000 a month. In October, 16,729 systems were added, or a total of 75MW (the average size if 4.2kW), taking the total for the year to 657MW.

GEM solar october

Meanwhile, construction in the large-scale renewable energy market is at a virtual standstill, thanks to uncertainty about the future of the large-scale target, which has caused banking finance to dry up, and its share of generation is also going backwards.

This is partly due to lower wind speeds, and lower hydro production as the incentive to generate more hydro is removed because of the dumping of the carbon price and the fall in the value of LGCs (certificates), due to the policy uncertainty. In October, the share of renewable generation (not including rooftop solar) was 13.1 per cent. This was down from 14.2 per cent in September and 18.3 per cent a year earlier.


In the past month, just four small solar power stations and a small hydro generator were approved in October.

gem power plantsSo far this year, it has been a sorry story for new developments. As this graph to the right show, less than 200MW of large-scale renewable plants have been accredited in 2014.

Of these, two plants, Boco Rock wind farm and the Portland wind farm extension, were committed last year, as was the 20MW Royalla solar farm which makes up the bulk of the solar total. The rest of the solar component include rooftop solar projects of more than 100kW, so too big to qualify for the small-scale scheme. Both Portland and Royalla have been supported by other schemes such as the Clean Energy Finance Corporation and the ACT government’s solar auction.

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  1. Alan Baird 6 years ago

    Frankly I wouldn’t be so half-hearted about “uncertainty” as the present state of affairs. When it comes to a choice between alternative and fossil energy, the Federal Govt is about as uncertain as ISIS is about about how to treat people who don’t agree with them. The only difference is the violence they’re prepared to use. Otherwise, there is absolutely NO doubt about what they’re contemplating.

  2. Peter Campbell 6 years ago

    “…and the SCT government’s solar auction” should be ACT not STC

  3. Ronald Brakels 6 years ago

    I guess this means South Australia would be up to around 580 megawatts of rooftop solar capacity now. If it puts out 77% of its full capacity at around noon that would come to about 447 megawatts on a cloudless day. While I don’t know that the 77% figure is correct for South Australia, it seems reasonable to me given the typical performance of rooftop solar systems. However the figure may be dropping as current low feed-in tariffs prompt people installing new solar to maximise self consumption over total kilowatt-hours.

    • David Osmond 6 years ago

      Hi Ronald, according to the APVI map, on a sunny day, SA seems to be getting just over 60% of full capacity at noon. I suspect the mixture of array alignments & shading effects all contribute to the lower figure.

      • Ronald Brakels 6 years ago

        Thanks for that, David.

        I would expect a typical new north facing rooftop solar system to produce about 80% of its rated capacity at noon with most of the loss coming from heat reducing the efficiency of the panels, and an east or west facing system to have a total output of about 80% of a north facing system, but at noon they would only be producing half as much as a north facing system. So if half our panels were facing north and half east and west, then at noon they would only be producing about 60% of rated maximum. Now half of systems facing directly east or west is an exageration but there’s still a large number not facing directly north. Also many systems will be limited by the size of their inverter at around noon and in the past inverters weren’t as efficient as they are now. And older systems will have undergone some degradation but installations only really took off from 2008 so this won’t be much of an effect. Shading wouldn’t be a problem at around noon.

        So I guess I should lower my estimate of much South Australia’s rooftop solar will produce at noon, although I am still a bit surprised the APVI map tends to gives a noontime output of only about 60%, though I do see though that at one point they were briefly up to 69% in the early afternoon.

  4. Miles Harding 6 years ago

    A proliferation of rooftop PV and ultimately storage at the household and community level is possibly the worst outcome for the incumbent players.
    I have no pity for them, as they have had no small part in creating this situation through their lack of vision and failure to engage with their customers.

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