25 Years of the RET: The Quiet Policy That Put Solar on 4 Million Roofs

This year marks 25 years since Australia’s Renewable Energy Target began operating. Most people have never read a word of it, yet it has probably touched your life more than almost any other energy policy: it is the reason more than four million Australian rooftops now carry solar, and it is the discount quietly built into every solar and battery quote you have ever received.

We have a particular fondness for this anniversary. Rainbow Power Company had already been designing and installing solar for 14 years when the RET switched on in 2001. We watched the scheme arrive, evolve, survive the odd political storm and transform our industry. So here is the story of the RET in plain English: where it came from, what it achieved, and what it still does for you today, in the handful of years it has left.

Where the RET came from

The idea was announced in 1997 and became law as the Renewable Energy (Electricity) Act 2000, with the scheme commencing on 1 April 2001. The original version, the Mandatory Renewable Energy Target, had a modest goal by today’s standards: an extra 9,500 gigawatt-hours of renewable generation a year by 2010, roughly two per cent of the nation’s electricity at the time.

The design was elegant, and it has barely changed in a quarter of a century. Renewable generators earn a certificate for each megawatt-hour of clean electricity they produce. Electricity retailers are legally required to buy and surrender a set number of those certificates every year. That creates a market: the certificates have value, the value flows back to whoever built the clean generation, and the whole thing is funded through the electricity market rather than government handouts. No annual budget fights, no grant rounds. Just a steady, legislated pull towards cleaner power.

A quarter-century in five milestones

• 2001 – The Mandatory Renewable Energy Target commences on 1 April with a 9,500 GWh target, among the first schemes of its kind in the world.
• 2009 to 2010 – With bipartisan support, the target is expanded to the equivalent of 20 per cent of Australia’s electricity by 2020, and soon after is split into two parts: the Large-scale Renewable Energy Target (LRET) for wind and solar farms, and the Small-scale Renewable Energy Scheme (SRES) for household solar.
• 2015 – After a period of political uncertainty, the large-scale target is settled at 33,000 GWh by 2020, restoring investment confidence.
• 2019 – The Clean Energy Regulator confirms enough capacity has been built to meet the 2020 target, more than a year ahead of schedule.
• 2025 – The SRES mechanism gets a new job: delivering the federal Cheaper Home Batteries discount, which has made batteries the fastest-growing part of our industry.

What it actually achieved

When the RET began, renewables supplied around a tenth of Australia’s electricity, and almost all of it was hydro built decades earlier. Today renewables supply well over a third and climbing, on the way to the current national goal of 82 per cent by 2030. The RET did not do that alone, but it did the crucial early work: it made wind farms bankable, it dragged solar from a niche product into a mainstream one, and it built an industry, with the installers, engineers, standards and supply chains that everything since has relied on.

The number we find most remarkable is the small-scale one. More than four million Australian homes and small businesses now have solar on the roof, one of the highest rates in the world. Every one of those systems was helped over the line by the same certificate mechanism written into that 2000 Act. For a policy most Australians could not name, that is an extraordinary legacy.

The part you can still use: STCs

Here is where the anniversary stops being history and starts being practical. When you get a quote for solar, there is a line on it, sometimes labelled “STC discount” or “government incentive”, that knocks thousands of dollars off the price. That is the RET at work. Small-scale technology certificates are created based on the electricity your system is expected to generate between installation and the end of 2030, and your installer typically claims them for you and passes the value on as an upfront discount.

For a typical 6.6 kW system in our part of the world, that is currently in the order of 45 certificates, commonly worth around $1,700 to $1,800 depending on certificate prices at the time. You do not fill in a form or wait for a cheque; it is simply baked into the quote.

Since 1 July 2025, the same rails have carried the federal battery discount under the Cheaper Home Batteries Program, which takes roughly 30 per cent off the installed cost of a home battery. The program was expanded in December 2025 after demand far outstripped expectations, and its settings were adjusted from 1 May 2026, with the discount now stepping down every six months rather than yearly.

The clock built into the scheme

The RET was never designed to run forever. The small-scale scheme is legislated to end on 31 December 2030, and because certificates are calculated on the years remaining until then, the discount on a new solar system gets a little smaller every 1 January. A system installed in 2026 earns certificates for five years of deemed generation; wait until 2028 and the same system earns them for only three. The battery discount now steps down even more often.

We are wary of countdown-clock sales tactics, and solar stacks up on its own economics these days. But it is a plain fact of the scheme’s design that the incentive is at its largest right now and shrinks from here. If solar or a battery is already on your list, the certificate maths rewards doing it sooner rather than later.

Older than the scheme itself

Rainbow Power Company was founded in Nimbin in 1987, back when solar meant a panel, a battery bank and a long way to the nearest powerline, and 14 years before the RET existed. We have now worked under the scheme for its entire 25-year life, through every rule change, multiplier and review. That history is worth something practical: schemes come and go, but a well-designed system keeps delivering long after the incentive that helped pay for it is gone. That is how we build them.

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