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It might also surprise you to know that nearly 15% of Australian households have solar panels on their roofs. That’s the highest number of solar panels on people’s roofs per capita anywhere in the world. – Energy Minister Josh Frydenberg, speaking on Q&A on March 22, 2106.

Solar photovoltaics (PV) technology produces electricity directly from solar energy. When you see a solar panel on a household roof, it’s most likely solar PV technology at work within those shiny blue or black, silver-framed plates. (If not, they’re likely to be solar hot water system panels.)

Solar PV has made a valuable contribution towards reducing Australia’s very high per-capita greenhouse emissions from electricity generation.

Energy Minister Josh Frydenberg’s told Q&A viewers that Australia has more household solar panels, per head of population, than anywhere in the world.

Let’s check the claim against the available evidence.

Checking the source

When asked for a source to support his assertion, a spokesman for the minister clarified he was talking about solar PV systems only (not solar hot water).

He referred The Conversation to a document produced by the Energy Supply Association of Australia (which has since been folded into the new Australian Energy Council). The document said that:

Australia clearly leads the world in the installation of household scale distributed solar PV. Australia has double the residential solar PV penetration rates of the next country (Belgium), and more than three times the penetration of Germany and the UK … By 2015, more than one in seven Australian households had installed solar PV. This is a 15% penetration rate across all Australian households.

We can check this assertion independently using a combination of data from:

the Australian PV Institute’s database of PV systems less than 10 kilowatts registered with the Australian Clean Energy Regulator and;

a March 2015 data set from the Australian Bureau of Statistics (ABS) called Household and Family Projections, Australia.

Note that the kilowatt (kW) capacity here refers to the size of the PV system, and represents the maximum power (Watts) the system generates in the middle of a sunny day.

A typical PV panel is rated at around 250 Watts (0.25kW). A typical residential PV system in Australia is sized somewhere between 1.5-5kW, or 6 to 20 panels. As a basis for comparison, a typical air-conditioner typically consumes around 1-2kW when running.

For our calculation, we assumed that all systems less than 10kW are installed on household premises (although, in fact, a few are installed on small businesses and community buildings such as surf clubs and schools).

Here’s what the data show:

So Frydenberg has actually likely slightly underestimated the proportion of Australian households with a PV system. It’s not 15% – it’s more like 16.5%, according to the latest data.

PV systems are not evenly distributed across Australia’s residential sector, as the Australian PV Institute’s live PV map shows:

Is Australia the world leader when it comes to household solar PV per capita?

Yes. Australia does likely have the highest proportion of households with PV systems on their roof of any country in the world.

But to be clear, Australia does not have the most PV rooftop capacity installed per person. By that we mean there are a number of other countries that currently generate a higher proportion of their total electricity from PV than Australia.

Those countries may also have larger commercial and industrial PV systems (often tens to hundreds of kilowatts in size) or utility PV plants (which can be a megawatt – 1,000 kilowatts – to tens of megawatts in size).

PATRICK PLEUL EPA/PATRICK PLEUL

Australia is unusual in that some 85% of its installed PV capacity is small systems less than 10kW.

Indeed, the latest International Energy Agency (IEA) Photovoltaic Power Systems Programme Task 1 trends report ranks Australia fourth or fifth for overall PV capacity, based on 2014 data:

Note, however, that not all countries with high PV penetrations are included in the IEA report. Greece, for example, gets around the same proportion of its electricity from solar PV as Germany.

There are also a number of small island developing states with a high percentage of households with stand-alone solar home systems. For example, around 17% of households in Kiribati have a solar home system (based on 2013 data).

However, this isn’t really comparable with Australia because these PV systems in Kiribati are so tiny they can only power lighting and small appliances. Also, Kiribati’s population is only just over 100,000 people and many people on remote islands have no access to an electricity grid.

In 2014, Germany had more than nine times the installed PV capacity of Australia, yet around the same number of household PV systems spread over more than three times the population.

Italy had more than four times the PV capacity of Australia, yet less than half the number of household PV systems. Japan had around 15% more residential PV systems, but more than five times the population of Australia. Belgium has a population around half that of Australia, but only around one fifth the number of PV systems. Greece has less than a tenth of Australia’s PV capacity of small (<10kW) PV systems.

Therefore, all of these countries have a significantly lower proportion of households with PV systems than Australia. They do better than Australia when it comes to total energy produced from solar; they do worse than Australia when it comes to household rooftop solar only.

So Frydenberg was right to say Australia has the highest proportion of households with PV systems on their roof in the world (well, that is if we don’t consider tiny countries like Kiribati).

Why is household rooftop solar so popular in Australia?

Australia’s unique PV market focus on households has come about through a combination of factors:

Policy support from federal and state governments has historically focused particularly on PV systems less than 10kW, including the Solar Credit Multiplier available over 2009-2012 through the former Labor government’s revised Renewable Energy Target. There were also the various state-based feed-in tariffs over the same time period, which were generally restricted to small PV systems. A large proportion of Australian housing comprises stand-alone dwellings with relatively large roof spaces suitable for PV systems. Most of Australia has an excellent climate for PV systems with plenty of sunshine. Australian households have to pay very high residential electricity prices compared to many other countries. PV systems can be a very cost effective way to reduce household electricity bills. Australia’s relatively high rates of owner-occupier home ownership allows the benefits of the PV system investment to be captured by the home owner, who also pays the electricity bills.

What does the future hold?

One final note: Australia may be at risk of losing the top ranking when it comes to household solar PV systems.

A growing number of countries are setting ambitious PV targets.

In Australia, some key electricity industry stakeholders here in Australia – including the distribution network utilities that own and operate the wires that run to your house – are looking to restrict future household PV connections in some areas, or reduce the money that households can save by installing PV systems.

Household PV does raise a number of technical challenges for these businesses, and their revenue under current electricity tariffs.

Verdict

Josh Frydenberg was correct. Australia almost certainly has the highest proportion of households with PV systems on their roof of any country in the world (again, not including tiny nations like Kiribati). His assertion that nearly 15% of Australian households have solar panels on their roofs was, indeed, perhaps a slight underestimate.

However, there are a number of other countries that currently generate a higher proportion of their overall electricity from PV than Australia.

Unlike these other PV markets, the great majority of PV systems in Australia are small-scale installations on household rooftops. If Australian governments are keen to see Australia retain its world leading position, greater policy, retail market and regulatory efforts will be required. – Anna Bruce and Iain MacGill

Review

This is a sound analysis. The author has provided evidence that clearly demonstrates that over 15% of Australian households have photovoltaic solar power, and that, excepting tiny island nations, that this is the highest percentage in the world.

The author’s conclusion that there are also other countries with a much higher capacity (in terms of power per person) and higher fraction of their electricity from photovoltaics is also accurate and justified.

The high proportion of households with PV power on their roofs is due to our high electricity prices and sunny climate, making PV especially attractive to consumers in Australia.

As the author notes, the market where Australia is currently missing out is large-scale solar.

As photovoltaic power prices continue to fall, solar farms will become more and more economically attractive, especially in regional areas. Nevertheless, the countries that are leading the way in large-scale solar - China, the US and the UK - all have supportive policy frameworks. – Kylie Catchpole

AAP Image/Australian Renewable Energy Agency

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