Batteries continue to be deployed at all levels, from concurrent battery and solar PV installations on households to utility-scale batteries directly connected to the transmissions network. State schemes play a key role in uptake at the residential level. Batteries can increasingly be economically integrated into the electricity system providing essential grid stabilisation abilities at crucial times. This has assisted in the growth of community and grid-scale batteries.

There were 7563 concurrent solar PV and battery installations in 2019, a 33 per cent increase in the 5689 battery installations in 2018²⁰. Most concurrently installed batteries are installed on solar PV sized between five and 10 kilowatts. This combination of technologies unlocks the most additional value by storing excess electricity generated during the day for use during peak evening hours.

Figure 7: Number of concurrent battery installations by solar PV system size and battery capacity

When consumer-owned energy storage devices are combined with rooftop PV, they can be aggregated and operate together as virtual power plants. The central management of these aggregated systems allows dispatch or consumption of electricity to manage local voltage or frequency variations, providing flexibility and stability to the electricity grid. The South Australia virtual power plant exemplified these traits. In October 2019, during an unexpected outage of the largest generating unit in the National Electricity Market, Kogan Creek in Queensland²¹. Subsequently the power system frequency immediately dropped below the normal operating range. The South Australia virtual power plant detected this frequency variation and responded immediately to inject power into the system to assist in frequency recovery.

The early success of the South Australia virtual power plant in demonstrating frequency control capabilities across multiple unexpected outages has underpinned the expansion of the state’s virtual power plant from 1,100 to a planned 50,000 systems²². This success has led to further trials in New South Wales and the Australian Capital Territory.

Ballarat Energy Storage System. Photo: Consortium comprising AusNet Services, Spotless, EnergyAustralia and Fluence.

Domestic battery. Photo: Jonathan Mandl, Clean Energy Regulator.

Footnotes

20. This is based on data disclosed voluntarily to the Clean Energy Regulator on batteries installed concurrently with solar PV.
21. Australian Energy Market Operator, AEMO Virtual Power Plant Demonstration, March 2020.
22. South Australia Department of Energy and Mining, South Australia’s Virtual Power Plant.