Storage combined with solar is still extremely limited in most markets. But in Australia, experts believe the economic conditions are ideal for enabling explosive growth.

“Solar and battery storage is simply unstoppable,” said Kobad Bhavnagri, head of Bloomberg New Energy Finance in Australia, in a recent analyst note. Bhavnagri predicted that 33 gigawatt-hours of battery storage, plus 37 gigawatts of solar PV, would be installed in the country by 2040. The technology set already beats Australia’s expensive grid electricity prices, he wrote.

However, regulatory uncertainty is a major problem for storage in the country. 

In its 2015 Emerging Technologies Information Paper, the Australian Energy Market Operator (AEMO) is far more cautious about storage paired with PV, predicting just under 8 gigawatts by 2035.

Due to varied rate structures and interconnection policies across the different regions of Australia, AEMO’s Stuart Allott cautioned that “the integration of storage is still very much in its infancy in Australia.”

But there are plenty of signs that the Australian residential storage industry has favorable growth prospects. For example, one in four households installing new solar arrays are also investing in battery energy storage.

Luke Osborne, co-founder of Reposit Power, which supplies control software for residential storage products, identified three factors contributing to those numbers.

First, Australia has an extraordinary solar resource, which allows systems to achieve twice the output that they would in Europe.

The country also has high electricity prices -- a consequence of an over-build of the grid system -- that make solar and storage a sound economic choice. 

Finally, said Osborne, the national electricity market is fairly well designed. "Despite consumer participation being fairly new, the market can accommodate it," he said.

There are numerous companies eager to serve the Australian market, including AGL Energy Limited. The company has developed a battery system called the PowerLegato, which retails at AUD $9,990 (USD $7,300) to retrofit an existing solar system.

The system includes the 7.2-kilowatt battery itself, provided by Taiwanese firm AU Optronics, as well as a 3-kilowatt inverter, plus the installation -- both of which seem to be missing from Tesla's Powerwall pricing. In addition, a 10-year guarantee is included.

AGL has gone to great lengths to develop a product tailored to the needs of the Australian market, says the company. It argues that the Powerwall’s 2 kilowatts will not be enough for households that want to run their air conditioners and dishwashers in the evening, and also want to keep the lights on. (In fairness, Tesla has promised to increase the Powerwall's capacity to 5 kilowatts in response to "negative feedback.")

Unlike the Powerwall, AGL’s PowerLegato energy storage system is available now. According to company spokesperson Kathryn Lamond, AGL will also be offering solar-plus-storage bundles at attractive prices in the near future.

Despite having 2,000 existing energy customers already signed up to buy storage packages, AGL’s analysis of the current market is pragmatic.

“The residential market for batteries will remain fairly niche for the next few years, with early adopters of solar PV being the primary customer segment showing interest," said Lamond. "It will take time for the cost of battery cells and balance-of-system costs to come down to the point where battery storage takes off in any significant volume."

Another player in the growing market is LG Chem. Its first shipment has already reached Australia, and its 6.4 kilowatt-hour battery storage unit is being sold for AUD $6,898 (USD $5,100).

According to GTM Research energy storage analyst Brett Simon, the LG Chem offering is a "significant step" for the Australian market. "There are currently players in the residential solar-plus-storage market, but LG’s system is significantly cheaper," he said.

And unlike AGL, LG already offers solar and storage as a bundle, as well as including an inverter and an energy management system for about AUD $24,000 (USD $17,600).

If that weren’t enough, there are a whole bunch of other organizations that are betting on Aussie energy storage by offering their own residential systems. These include Samsung SDI, BYD, Panasonic and startup Squirrel Energy.

Their willingness to invest in Australia is a strong indicator that solar-plus-storage is about to take off down under.