It is, as Jason Froud knows all too well, a little-known but fundamentally important aspect of the power system.

When you flick a switch, the electricity that illuminates the light in the room is new.

Brand new.

“Traditionally, you’ve had the electricity system that has generated the electricity at the moment that it’s used,” Mr Froud said.

“When you look at a light that’s shining in your room or your office, the light that you’re looking at is being generated at exactly the same moment you’re seeing it.”

The need to meet demand with supply the instant it arises has been a defining characteristic of the electricity system ever since it was invented more than 100 years ago.

Someone, somewhere generates the electricity you need at the moment you need it.(Unsplash: Tungsten light bulb by Anthony Indraus)

It owes much to the fact that unlike other commodities, from wheat to water and so many others besides, there has traditionally been little ability to store electricity for later use.

But Mr Froud, a general manager at state-owned West Australian power provider Synergy, said this historic limitation of energy supply was changing.

“With electricity storage coming into the market more and more, it’s almost turning electricity more into a traditional type of commodity,” he said.

“You can store it and then use it when it’s required.”

Sun rises over coal’s demise

Earlier this year, Synergy switched on a large-scale battery at a site south of Perth, which promises to be the first of several owned by the firm.

The battery, which can provide up to 100 megawatts of power flat out for two hours, has not come a moment too soon.

Synergy’s big battery south of Perth will soon be eclipsed by two much bigger versions.(Supplied: Synergy)

Like all electricity systems across Australia, WA’s main grid is grappling with tectonic shifts as part of the move away from conventional fossil fuel-fired generators to renewable sources.

No time of year illustrates the magnitude of the upheaval better than springtime, when soaring output from rooftop solar panels, in particular, coincides with mild temperatures and often low demand for power.

In recent weeks, a series of records have been broken in Australia’s main electricity systems, where renewable energy generation is reaching new highs.

Simultaneously, coal-fired power production has plumbed new lows from one side of the continent to the other.

Energy Corporation of New South Wales director Alex Wonhas said the extraordinary rise of rooftop solar was driving many of the most recent records.

He noted there were now more than three million households across the country with solar panels on their roof and their output, combined, was dominating the electricity system for hours at a time.

He said as a consequence, minimum demand for power from the grid – which excludes the demand that customers were meeting themselves through their solar panels – was plunging ever lower.

Coal plants such as Bayswater in NSW are having to reduce output to accommodate rooftop solar.(Supplied: AGL)

Batteries help ‘fill in blanks’

According to Dr Wonhas, this was posing challenges for the stability of the grid because many of the displaced coal- and gas-fired generators were still needed when the sun was not shining.

But he said batteries and other forms of storage would be invaluable in helping to provide back-up.

“I think we need to be much more strategic in what we do with storage,” Dr Wonhas said.

“That means in the middle of the day this storage can really absorb some of that excess solar and then release it, in particular in the early evening period when power will be really important.”

Along with large-scale installations, Dr Wonhas said there would be a need for batteries of all sizes as Australia moved towards a less centralised, more diffuse power system.

To that end, poles-and-wires company Western Power has installed about a dozen “community” batteries across Perth to store customers’ excess solar generation in the middle of the day and provide it back to them later.

Andrew Blaver says batteries will be the “Swiss army knife” of the power system.(ABC News: Claire Moodie)

Andrew Blaver, the utility’s head of changing energy solutions, said these assets were much smaller than a utility-scale battery but were materially bigger than a typical household system.

He said community batteries were already helping to keep costs on the low-voltage distribution network down by reducing the need to upgrade infrastructure to cope with peak demand.

‘A Swiss army knife’ of energy

Crucially, Mr Blaver said they were also enabling the network to deal with ever-growing amounts of rooftop solar exports.

“We recognise that battery storage really is going to do a lot of the heavy lifting,” Mr Blaver said.

“It’s almost like the Swiss army knife technology for the network.

“We’re convinced that storage at all levels of the energy system needs to … and will have greater demand for them to be connected to the system.

Batteries are helping poles-and-wires companies to squeeze more capacity from the network.(Supplied: Western Power)

“It’s really about not wasting the cheap renewable, plentiful energy that’s connecting to the network.

“When it is plentiful and cheap, let’s store it somewhere and then let’s release it later when it isn’t cheaper and when there are constraints on the network.”

George Martin, chief technology officer of Plico, a company running a so-called virtual power plant across about 1,500 homes in WA’s main electricity grid, said at a household level batteries were increasingly part of the answer too.

Under the company’s business model, households lease solar panels and batteries, which can be used to help stabilise the grid at times of stress.

“As an aggregator, we are essentially the maestro of a virtual power plant and we can get all the systems in people’s homes to work in concert with each other to actually provide valuable services to the grid,” Mr Martin said.

“That way the whole thing is greater than the sum of its parts.”

Virtual power plants involve “aggregating” household solar and battery systems.(Supplied: Plico)

More, much more, needed

For Mr Martin, Australia’s energy transition requires the country to fundamentally change how it generates and uses power.

He said Australia was essentially moving from a system in which electricity was generated to meet demand as it arose to one in which demand increasingly had to accommodate the variability of supply.

Storage including batteries, he said, were the key to this.

“I think batteries provide immense flexibility to tackle both the highs and the lows,” he said.

“With reference particularly to minimum demand, having a battery and being able to orchestrate it centrally means we can charge the batteries from the grid at times where there is minimum demand.

“By putting load on the grid, it absorbs the renewable energy that is flooding the grid from rooftop solar as well as utility-scale solar and wind power.

“Batteries are very unique and flexible in that they can provide services in peak demand and services in minimum demand.”

One in three Australian homes now has rooftop solar panels.(Supplied: Western Power)

Mr Froud agreed.

With Synergy set to commission two giant new batteries with a combined capacity of almost 3,000 megawatt hours by the end of 2025, he said a long-held goal of the transition would be within reach.

“You can start shifting load from the middle of the day and soaking up that excess rooftop solar and pumping it back into the grid at night when it’s needed,” Mr Froud said.