Rooftop solar on its own is already affordable enough to be a smart choice for virtually any Australian home with an unshaded roof and some daytime electricity usage. This is true even in the absence of generous, state-backed solar feed-in tariffs and the (slight) reduction of the up-front incentive for solar available through the federal Renewable Energy Target. In fact, Aussie homes have been installing solar at a steady pace long after the most generous incentive programs were closed to new applicants.
The key to getting the most out of a solar PV system these days is to use as much of the energy as possible directly, within the home (‘solar self-consumption‘). Self-consuming solar energy helps the home to avoid purchasing energy from the grid, thereby saving between about $0.20-$0.30 per kilowatt-hour (kWh) depending on where they live and their electricity retailer. The rate solar households are paid to send their excess solar in the grid, on the other hand, is about 8-15c/kWh.
Solar system installation prices have been steady for the past few years- we know because we keep track of them in our Solar PV Price Index. No sudden reductions (or increases) are likely to be on the horizon; the market has stabilised after the initial turmoil of its first few years.
Lots of things have changed in recent years with regard to solar power for homes. The business case for going solar – the investment-worthiness of solar panels – has quickly progressed through roughly three stages since the solar panel boom began in Australia in around 2008.
Making a long story short, these stages were:
Stage 1 (until about 2011): High solar system prices, high incentives. Lots of people installed solar despite relatively high prices thanks to government incentives on the federal and state level. “Solar is a no-brainer, and there’s a deadline!”
Stage 2 (2011-2013/2014): Falling solar system prices, falling incentives. System prices fell, but so did incentives, creating a landscape of uncertainty. “Is solar still a good idea?”
Stage 3 (2014-present): Relative stability. Solar PV system prices come down significantly, and upheavals in the solar incentive sphere cease.
At this point, it seems fairly clear that residential solar power is here to stay in Australia. Over 2 million homes already have a solar PV system, and there is now more than one panel installed per human being in the country. Virtually all industry analysts and investment houses – both within and outside Australia – are predicting that solar (and battery storage) are the future.
The strongest evidence for the permanence of solar as a household fixture in Australia is the solar system price trends witnessed over the past several years.
The chart below offers a glimpse into how average prices have changed since 2012. Systems cost about 50% less to install in February 2019 than they did in August 2012, according to the data that we’ve been keeping track of.
Several years ago, it was common for most homes to install 1kW, 1.5kW and 2kW solar systems. As prices have come down, however, the average solar system size has increased – and these days, 3kW, 4kW, 5kW and even 10kW solar systems are not uncommon. In fact, the larger system sizes almost always offer better value for money than smaller ones.
Generally speaking, it’s important for homes to choose a solar system sized appropriately for their situation – meaning that they can use at least 30% of the energy it produces directly. However, if they can use even more (e.g. 50%), then the business case gets even better. According to our data, with a self-consumption rate of 30%, payback times for 5kW solar systems are under 6 years on average, nationally; in Adelaide, Brisbane, Darwin, Perth and Sydney they’re easily under six years, as per the table below. The internal rate of return (IRR – a metric for comparing investments similar to ROI but more comprehensive) for a solar system in each city is easily over 15% – on average 18% but as high as 32% in Adelaide.
Note that the table below uses average system prices to be conservative. Solar system owners may see even shorter payback periods and better IRR if they find systems for less without compromising quality, or if they manage to increase their self-consumption rates above 30%.