Australia’s Rapid BESS Expansion Shows What Happens When Batteries Become Part of the Power Market Itself

⚡ iAtlas Daily #74 | Energy Storage & Power Infrastructure | October 2026

For most of the history of electricity, the power system operated according to one fundamental rule:

Electricity Had to Be Produced When It Was Needed

Demand increased.

Power plants generated more electricity.

Demand decreased.

Power plants reduced output.

Electricity was therefore unusual compared with most industrial products.

A factory can produce steel today and sell it later.

A warehouse can store semiconductors.

An oil tank can store fuel.

But large electricity systems historically had very limited ability to:

Store Electricity at Scale

Battery energy storage is beginning to change that.

Australia provides one of the clearest examples.

Its National Electricity Market is rapidly adding grid-scale batteries.

According to NEMPulse, by early October 2026 the NEM contained:

59 Grid-Scale Batteries

with approximately:

9.34 GW

of active power capacity and:

21.54 GWh

of energy-storage capacity. NEMPulse

These batteries are not simply backup systems.

They are actively:

Buying Electricity

Selling Electricity

Providing Grid Services

and increasingly:

Changing Electricity Prices

That represents a fundamental change in how electricity markets work.

🌍 The Big Story

Australia has become one of the world’s most important real-world experiments in:

Battery-Based Electricity Markets

The country combines several unusual characteristics:

Large Solar Resources

Large Wind Resources

Rapid Renewable Deployment

Coal Plant Retirements

Volatile Wholesale Prices

and:

Rapid Battery Construction

The result is a power system where electricity can be:

Extremely Cheap at One Time

and:

Extremely Expensive Hours Later

That price difference creates an opportunity for batteries.

The basic business model is simple:

Charge When Electricity Is Cheap

↓

Store the Energy

↓

Discharge When Electricity Is Expensive

This is called:

Energy Arbitrage

But something interesting happens when thousands of megawatt-hours of batteries begin doing this simultaneously.

They start changing the prices they were designed to exploit.

1. Why Electricity Prices Move So Much

Electricity prices depend on the balance between:

Supply and Demand

When electricity supply is abundant:

Price ↓

When supply becomes scarce:

Price ↑

Renewable energy makes this relationship more dynamic.

During a sunny afternoon, solar generation can become enormous.

Electricity supply increases.

Wholesale prices can fall sharply.

Sometimes prices can even become:

Negative

Then the sun sets.

Solar generation disappears.

But household electricity demand can remain high.

Suddenly:

Supply ↓

while:

Demand remains high

and prices can rise rapidly.

2. This Creates the Battery Opportunity

A battery can respond to that pattern.

During the afternoon:

Solar Output High

↓

Electricity Price Low

↓

Battery Charges

Then during the evening:

Solar Output Falls

↓

Electricity Price Rises

↓

Battery Discharges

The battery effectively moves electricity through:

Time

That sounds simple.

But economically, it is extremely powerful.

3. Batteries Turn Time into a Market

Electricity markets traditionally price energy according to:

Where

and:

When

it is needed.

Battery storage adds another economic layer.

A battery can purchase electricity at:

12:00 PM

and sell it at:

7:00 PM

The same electricity becomes more valuable simply because it is available:

At a Different Time

This means battery operators are effectively trading:

Time

4. Australia Is Scaling This Model Rapidly

Australia’s battery fleet has expanded quickly.

NEMPulse data covering the National Electricity Market shows active grid-scale battery capacity reaching approximately:

9,342 MW

and:

21,544 MWh

across 59 systems by early October. NEMPulse

That is enough capacity for batteries to become meaningful participants in electricity-market pricing.

This is no longer a technology demonstration.

It is becoming:

Power Infrastructure

5. Battery Revenue Is Already Significant

During Q3 2026, Australia’s grid-scale batteries generated approximately:

A$88.9 Million

in estimated gross energy and Frequency Control Ancillary Services revenue.

That was approximately:

57% Higher

than Q2. Energy-Storage.News

The fleet earns money from several sources.

One is:

Energy Arbitrage

But another important category is:

FCAS

or:

Frequency Control Ancillary Services

6. Batteries Can Respond Extremely Quickly

Electricity grids need to maintain frequency around a stable level.

When generation and demand become unbalanced, frequency can move.

Traditional generators can respond.

But batteries can respond:

Extremely Quickly

This makes them particularly valuable for grid stabilization.

Battery systems can inject or absorb power rapidly.

That means their economic value is not limited to:

Storing Energy

They can also provide:

Grid Stability

7. The Battery Is Becoming a Power-Market Asset

This changes how we should think about BESS.

A battery is not simply:

A Large Box of Cells

Economically, it is closer to a flexible power-market asset capable of switching between:

Consumer

and:

Supplier

When charging:

Battery = Electricity Buyer

When discharging:

Battery = Electricity Seller

When providing FCAS:

Battery = Grid-Service Provider

One physical asset can perform several economic functions.

8. Batteries Change the Demand Curve

Suppose solar generation becomes extremely high at noon.

Without storage:

Solar Supply ↑↑

↓

Wholesale Price ↓↓

But batteries begin charging precisely when electricity is cheap.

That creates additional:

Demand

So:

Battery Charging

↓

Electricity Demand ↑

↓

Very Low Prices Become Less Extreme

This is the first way batteries change electricity economics.

9. They Change the Supply Curve Too

Now consider the evening.

Solar generation falls.

Demand remains high.

Without storage:

Supply Tightens

↓

Price ↑↑

But batteries begin discharging.

That creates additional:

Supply

So:

Battery Discharge

↓

Available Electricity ↑

↓

Peak Prices Become Less Extreme

The battery therefore acts on both sides of the market.

10. The Price Curve Begins to Flatten

Conceptually:

Without Batteries

Very Low Afternoon Price

↓

Very High Evening Price

With Batteries

Higher Afternoon Price

↓

Lower Evening Price

The difference between low and high prices becomes:

Smaller

This is exactly what storage is supposed to do.

But it creates an unusual business problem.

11. Batteries Can Destroy Their Own Profit Opportunity

Battery arbitrage makes money from:

Price Differences

For example:

Buy at:

$20/MWh

Sell at:

$150/MWh

The spread is:

$130/MWh

But suppose many batteries enter the market.

They all charge when prices are low.

That pushes low prices upward.

Then they all discharge when prices are high.

That pushes high prices downward.

Eventually:

$20 → $40

and:

$150 → $100

The spread falls from:

$130

to:

$60

The battery fleet has reduced its own revenue opportunity.

12. This Is Self-Cannibalisation

Researchers studying Australia’s electricity market have identified precisely this effect.

A September 2026 study using five-minute NEM wholesale-price data found that:

Battery Charging → Raises Spot Prices

while:

Battery Discharging → Lowers Spot Prices

and that the resulting effect can lead to:

Self-Cannibalisation

as battery penetration increases. Crawford School of Public Policy

This is one of the most interesting developments in the energy-storage market.

Batteries become economically successful by reducing the market volatility that made them economically attractive in the first place.

13. We Can Already See It in Revenue Data

Battery fleet revenue can still be strong during volatile periods.

But normalized earnings are under pressure as more capacity enters the market.

Energy Synapse estimates that median BESS revenue across several Australian NEM regions fell by more than:

60%

in the 12 months through August 2026 compared with the previous 12-month period. energysynapse

The declines included approximately:

Queensland: −67%

South Australia: −66%

New South Wales: −61%

Victoria: −68%. energysynapse

That does not mean batteries stopped being useful.

It may mean precisely the opposite.

14. Lower Battery Revenue Can Mean a Better-Functioning Grid

This is an important distinction.

From the battery owner’s perspective:

Lower Price Spread = Lower Revenue

But from the electricity system’s perspective:

Lower Price Spread = Lower Volatility

That can benefit:

Consumers

Utilities

Renewable Generators

and:

Grid Operators

The battery can therefore become:

More Valuable to the System

while simultaneously becoming:

Less Profitable per MW

That is a fascinating economic paradox.

15. Australia Is Showing This in Real Time

AEMO has already described batteries as increasingly reshaping market outcomes.

During Q1 2026, renewable generation supplied:

46.5%

of NEM electricity—the highest first-quarter share on record.

At the same time, batteries played a growing role in the market while wholesale prices declined year-on-year. AEMO

The battery is becoming part of the mechanism that connects:

Variable Renewable Generation

to:

Reliable Electricity Supply

16. But Batteries Cannot Solve Every Problem

This needs an important qualification.

Battery storage is extremely effective at moving electricity across:

Hours

But not every energy shortage lasts a few hours.

Australia recently experienced a useful reminder.

During a period of extremely low wind generation in South Australia, battery output initially supported the system.

But battery reserves eventually became depleted during the prolonged scarcity period. The Australian

This demonstrates a fundamental limitation.

2-Hour Battery

cannot solve a:

2-Day Energy Shortage

17. Duration Is Becoming More Important

Early battery markets often focused heavily on:

Power capacity.

But increasingly we need to consider:

MWh

Energy capacity.

500 MW / 1,000 MWh

battery can theoretically discharge at full power for approximately:

2 Hours

500 MW / 4,000 MWh

battery can theoretically discharge for:

8 Hours

The power rating is identical.

The system value can be very different.

18. Australia Is Moving Toward Longer-Duration Batteries

Today’s news provides a strong example.

Origin Energy is seeking approval for:

Eraring BESS North

in New South Wales.

The proposed project would provide approximately:

500 MW

of power capacity and:

4,942 MWh

of accessible storage capacity. Ess News

That is nearly:

10 Hours

of energy at full rated output.

This is very different from the shorter-duration batteries that dominated earlier grid-storage deployment.

19. Eraring Could Become an Enormous Battery Hub

Origin is already developing battery capacity at the former coal-power hub.

If the new project proceeds, the combined Eraring battery precinct could reach approximately:

1.2 GW / 8.6 GWh. Ess News

The symbolism is difficult to miss.

A site historically associated with:

Coal Generation

is increasingly being paired with:

Large-Scale Energy Storage

This is not simply replacing one machine with another.

It represents a different power-system architecture.

20. Coal Stores Energy Before Electricity Is Generated

A coal plant effectively stores its energy in:

Fuel

Coal can sit in a stockpile.

When electricity is required:

Coal

↓

Boiler

↓

Steam

↓

Turbine

↓

Electricity

Renewable energy works differently.

You cannot stockpile:

Sunlight

or:

Wind

So renewable-heavy systems need another way to move energy through time.

Battery storage provides one answer.

21. The Storage Moves to the Electricity Side

The old system:

Stored Fuel

↓

Power Plant

↓

Electricity on Demand

The emerging system:

Solar / Wind

↓

Electricity

↓

Battery Storage

↓

Electricity on Demand

Storage has moved from:

Before Electricity Generation

to:

After Electricity Generation

That is a profound infrastructure change.

22. This Changes Renewable Economics

Without storage, renewable generators can face a problem.

When solar farms all generate simultaneously:

Electricity Supply Surges

↓

Prices Collapse

The more solar is installed, the more severe this effect can become.

This is sometimes called:

Renewable Cannibalisation

But batteries can absorb some of that excess electricity.

Instead of selling immediately at a very low price:

Solar

↓

Battery

↓

Evening Market

Storage therefore changes the economic value of renewable generation.

23. Cheap Electricity Becomes a Resource

Traditionally, extremely low electricity prices could be viewed as a problem.

They suggested:

Too Much Supply

Storage changes that perspective.

Very cheap electricity becomes:

Input Energy

for a battery.

The battery can convert:

Low-Value Electricity

into:

Higher-Value Electricity Later

This creates an entirely new industrial value chain around timing.

24. China Is Pushing the Cost Floor Even Lower

Australia demonstrates the market mechanics.

China demonstrates the manufacturing economics.

Wood Mackenzie’s October 2026 Asia-Pacific LCOE analysis estimates China’s four-hour battery-storage benchmark at approximately:

US$58/MWh

more than:

55% Below

the average across the rest of Asia Pacific. Wood Mackenzie

That cost advantage matters because cheaper storage changes where batteries become economically viable.

25. Lower Storage Cost Expands the Market

Imagine a battery project costs:

$200

to provide a certain amount of stored electricity.

Only very large electricity-price spreads justify the investment.

Now suppose battery costs fall dramatically.

The project may become viable with a much smaller price spread.

That means lower battery cost allows storage to enter:

More Electricity Markets

And as storage enters more markets:

Electricity Prices Change

This creates a reinforcing cycle.

26. But China Has the Opposite Problem on the Manufacturing Side

Demand for energy storage is growing rapidly.

Yet Chinese battery manufacturing capacity has expanded even faster.

In September, Reuters reported that China temporarily paused approvals for new battery-storage manufacturing projects amid concerns about excess capacity. Reuters

So two different forms of cannibalisation are emerging.

Electricity Market

More batteries reduce electricity-price spreads.

Battery Manufacturing

More factories reduce battery prices and manufacturer margins.

Both push:

Storage Costs Down

27. That Can Accelerate the Energy Transition

This is where the economics become especially interesting.

Battery manufacturers may dislike falling battery prices.

Battery operators may dislike shrinking arbitrage spreads.

But electricity systems can benefit from both.

Cheaper Batteries

↓

More Storage Deployment

↓

More Renewable Integration

↓

Lower Price Volatility

↓

Lower Storage Revenue per MW

↓

Need for Even More Efficient Storage

The industry begins to optimize itself.

28. Battery Business Models Will Need to Evolve

Pure arbitrage may become less attractive as battery penetration increases.

Future storage projects may increasingly combine several revenue sources:

Energy Arbitrage

FCAS

Capacity Payments

Network Services

Long-Term Contracts

Renewable Firming

The battery becomes:

A Multi-Service Infrastructure Asset

rather than a simple trading machine.

29. Software Becomes More Important

When battery revenue depends on multiple markets, operating strategy becomes critical.

The system must continuously decide:

Should I charge now?

Should I discharge now?

Should I reserve capacity for FCAS?

Will prices be higher later?

How much state of charge should I preserve?

These decisions increasingly rely on:

Software

Forecasting

and:

Algorithmic Bidding

So the energy-storage value chain expands beyond battery hardware.

30. The Battery Is Becoming Part of Electricity-Market Architecture

This is the larger structural shift.

The first generation of battery-storage discussion focused on:

Battery Technology

Chemistry.

Cycle life.

Energy density.

Safety.

Cost.

Those remain essential.

But grid-scale storage introduces another question:

What does the battery do to the market around it?

Australia is beginning to provide the answer.

It:

Moves Energy Through Time

Reduces Price Extremes

Supports Renewable Generation

Provides Grid Services

and eventually:

Changes Its Own Economics

That is what happens when a technology moves from being a product to becoming infrastructure.

🧩 Why This Matters

Battery storage is becoming a major electricity-market participant.

Australia’s NEM now has roughly 9.34 GW / 21.54 GWh of active grid-scale battery capacity across 59 systems. NEMPulse

Batteries can reduce electricity-price volatility.

Charging adds demand during low-price periods while discharging adds supply during high-price periods. Academic research using Australian market data finds both effects clearly. Crawford School of Public Policy

That creates self-cannibalisation.

As more batteries enter the market, the price spreads that generate arbitrage revenue can shrink.

Battery duration is becoming increasingly important.

Projects such as Origin’s proposed 500 MW / 4.94 GWh Eraring BESS North show the market moving toward much longer storage durations. Ess News

Storage economics are improving rapidly.

China’s four-hour storage benchmark is estimated at around US$58/MWh, dramatically below much of the rest of Asia Pacific. Wood Mackenzie

The battery business model is becoming more sophisticated.

Future BESS economics will increasingly depend on combining arbitrage, grid services, contracts and optimized software operation.

🔭 What to Watch

Battery Revenue Cannibalisation

Watch whether MW-normalized battery revenues continue declining as Australia’s installed BESS fleet expands.

Long-Duration Storage

The transition from 1–2 hour systems toward 4, 8 and even 10-hour battery projects could materially expand the role batteries play in power systems.

Eraring BESS

Origin’s proposed expansion could turn the former coal-generation precinct into approximately 1.2 GW / 8.6 GWh of battery infrastructure. Ess News

China Storage Costs

China continues to establish an extremely low manufacturing and storage-cost benchmark. Watch whether these economics spread into other markets.

Multi-Service Revenue

Battery operators will increasingly need revenue beyond simple wholesale arbitrage.

AI and Data Centers

Rapidly growing electricity demand from data centers could create another major source of demand for firm, dispatchable renewable power—and therefore storage.

🧭 iAtlas Insight

The most important thing about battery storage may eventually be:

Not the Battery

but what the battery does to:

Electricity

For more than a century, electricity systems were designed around a physical constraint:

Power had to be generated when consumers needed it.

Storage weakens that constraint.

Electricity generated at noon can become electricity consumed at night.

Cheap electricity can be moved into expensive hours.

Renewable generation can become more dispatchable.

And price volatility can be compressed.

The progression looks like this:

Battery Cell

↓

Battery Pack

↓

BESS

↓

Grid Asset

↓

Electricity-Market Infrastructure

At the beginning of this transition, batteries profit from electricity-market volatility.

As deployment increases, they reduce that volatility.

Their own arbitrage opportunity becomes smaller.

And the business model must evolve again.

That sounds like a problem.

But from the perspective of the electricity system, it may actually represent success.

The ultimate sign that battery storage is transforming electricity may be that the market becomes less volatile precisely because so many batteries are operating inside it.

Australia is beginning to show what that future looks like.

And other electricity markets may soon follow.

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🔗 References

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