Australia’s Leanings Towards Battery Storage Over New Transmission

It is no secret that power distribution firms worldwide are considering energy storage options in a big way to augment or even defer investments in transmission system updates. Part of the reason is the higher share of intermittent renewable energy, but another is simply the variable nature of power demand, where a network can be severely under, or over-utilised at some times of the day. With terms like “virtual transmission” in Australia and “GridBooster” in Germany, the pipeline of energy storage projects is growing bigger every quarter, after having been estimated at 3 GW at the beginning of this year.

For Australia, congestion on the transmission network has already led to some big moves. From the pioneering Hornsdale battery reserve, to the recent Victoria big battery, the country has picked to go with some of the largest battery storage projects so far. That is because network congestion in its largest cities, Sydney and Melbourne during the heat of summer, when temperatures often hit 50 degrees C, is a serious issue. Transmission lines running at full capacity can struggle to serve all the load during the hottest day. A single transmission line outage across the state boundary can create power price surges of $14,000/MWh or brownouts—as happened in New South Wales during August 2018, when the QLD-NSW interconnector tripped due to a lightning strike.

Virtual transmission, now catching attention involves placing energy storage on a transmission line and operating it to inject or absorb real power, mimicking transmission line flows—essentially replacing the need for a line upgrade or new line to be built. Using energy storage to add transmission capacity like this represents a new approach to solve congestion that can enable hundreds of megawatts of capacity to be added to lines in less time, at lower cost.

The Australian Energy Regulator (AER) has started  telling power network owners in the country to look at the installation of big battery storage  to keep costs in check for a required upgrade of the country’s transmission infra.

With an estimated spend of  $8 billion to 2025, the AER is keen to explore the use of distributed energy resources, or large batteries in this case, to optimise network use.

Using battery storage with transmission offers faster deployment, take up lesser land, are flexible, and in some cases, can be easily relocated too. Add the other benefits they can offer, be it reactive power, frequency and voltage control and special protection schemes. The business model is also interesting for many network owners, at a fixed annual rental cost, much like the fixed costs we see state governments pay to power plants in India to provide stand by power.

Australia, thanks to its experience with the Hornsdale battery, is becoming the market to watch, as it seems most committed to using battery storage.

In India, we have seen how the giant Ladakh solar park plan for 7.5 GW solar has been stuck due to, among other things, issues on how to use spare capacity on the transmission infrastructure it will require, when solar generation is no longer happening in the evenings. A large battery might yet provide an answer there.