The ability of rooftop solar PV and solar hot water to displace fossil fuel generation has been underlined by the latest annual review by the Clean Energy Regulator, the body that oversees the federal renewable energy target.
The report says that more than two million installations of rooftop solar PV and solar hot water across the country has the capacity to generate or displace around 6,882 gigawatt hours of electricity a year.
By way of comparison, that is equivalent to a 1,000MW coal-fired power station operating full-pelt, although the impact on generators is far greater than that because solar steals revenue during the day-time period, the most profitable time of generation for fossil fuel plants, and so has caused much more than this to be closed or mothballed.
As this graph below highlights, the contribution in generation from small‐scale rooftop solar PV has trebled in the past three years to 3,766GWh. Combined with other small scale generation such as wind and hydro, this adds up to 4,182GWh. Solar hot water systems have displaced a further 2,700GWh of otherwise required generation.
The CER said this had reduced emissions by 20 million tonnes over the past decade. It is forecast that if the RET stays in place, then it would likely displace 100 million tonnes of CO2-e in the current decade.
The CER says that under the small‐scale component of the RET, some 238,769 small scale renewable energy systems were installed in 2013, taking the total beyond two million. This graph shows the surge in growth in recent years.
In 2013, the greatest number of solar panel installations was in Queensland (36 per cent) followed by New South Wales (17 per cent) and Victoria (16 per cent). In the last year, and despite the reduction in federal incentives and state-based feed in tariffs, an average of 15,460 small generation (mostly solar PV) were installed each month across the country, along with 4,250 solar water heaters.
The CER says the current capacity of accredited renewable energy power stations in Australia is approximately 18,600 megawatts. These power stations are able to generate around 16,000GWh of renewable electricity in a typical year, although this can depend on weather events, including rainfall in catchments that feed into hydro power station storage dams.
Graph 2 shows large‐scale renewable electricity generation increasing since the commencement of the schemes.