South Australia‘s annual electricity consumption has decreased significantly, with home solar power systems partly to thank.

A recent report released by the Australian Energy Market Operator (AEMO) states South Australia‘s consumption of mains grid supplied power decreased by approximately 5% (700 GWh) in 2011-12 and is around 10% lower than was forecast.

The AEMO now predicts consumption to grow by just 0.9% over the next decade.

Aside from consumer response to the rapidly increasing electricity prices, one of the factors leading to the consumption reduction is the uptake of rooftop solar power systems in South Australia.

Among the National Electricity Market (NEM) regions, South Australia has the highest percentage of rooftop solar panels, with approximately one out of five SA homes having installed systems by the end of February this year – representing a total capacity of  267 MW.

According to the AEMO, residential solar panel installations are estimated to have generated 306 GWh of electricity in South Australia in 2011-12, which is equivalent to 2.4% of the state’s annual energy.

While 20% of the state’s residential rooftops now sport solar panels, the future is continuing to look bright for South Australia’s solar industry.

The AEMO forecasts rooftop PV-generated electricity will increase to 900 GWh by 2021-22 under a moderate uptake scenario and over a 10-year outlook period, the average annual growth rate of rooftop solar panel installations is predicted to be approximately 8%.

South Australia’s electricity prices jumped by a massive 17% on 1 August 2011 and rose an additional 18% recently. With the state’s solar feed in tariff incentives currently totaling 25.8c per kilowatt hour minimum; it means a 5kWsolar panel system installed in Adelaide and in many other areas of the state can often wipe out a household’s electricity bill altogether.

Payback time on such a system currently on offer by some providers is approximately 5.5 years; after which, the system will continue to generate what is essentially free electricity for decades; with perhaps only the solar inverter needing replacing during that time.