Australia’s Waratah Super Battery hit a major transformer failure. Here’s what it really teaches about designing, financing and operating resilient green grids.
Australia’s biggest battery just took a hit.
An 850MW grid-scale battery designed as a “giant shock absorber” for New South Wales is partially offline after a catastrophic transformer failure and is now in a planned shutdown window through early December 2025. For a project built to protect the grid during summer peaks, that’s not a minor hiccup.
This matters because large battery energy storage systems (BESS) aren’t side projects anymore. They’re core grid infrastructure, central to every serious net zero and green technology strategy. When a flagship project like the Waratah Super Battery stumbles, investors, insurers, system operators and policymakers all take notice.
Here’s the thing about the Waratah story: it’s not a failure of green technology. It’s a stress test. And it’s giving us a clearer view of what “resilient clean energy” really needs to look like in 2026 and beyond.
In this post, I’ll break down what’s happening at Waratah, why it matters for grid reliability, and what smart developers, utilities and investors should be doing differently on design, risk and data.
Waratah Super Battery: Australia’s ‘giant shock absorber’ under pressure
The core fact: the 850MW/1,680MWh Waratah Super Battery is running at roughly 40% of its intended power capacity and has entered a planned shutdown from 20 November to 2 December 2025.
The sequence looks like this:
- October 2025: a main transformer at Waratah experiences a catastrophic failure, described as such internally by Akaysha Energy’s CEO.
- Capacity drops: the project, designed for 850MW, is operating at around 350MW while maintaining its contractual System Integrity Protection Scheme (SIPS) performance.
- 20 Nov – 2 Dec 2025: a planned balance-of-plant shutdown is coordinated with AEMO and Transgrid. This pulls the remaining capacity offline temporarily during a period of rising summer demand.
- Financial impact: specialist broker estimates AU$50–80 million in potential losses, depending on replacement timelines and how insurance coverage applies.
Despite the transformer issues, Waratah is still providing its core SIPS service — a fast-response safety buffer that lets more renewable energy move across the grid without risking system collapse when something trips.
Most companies looking at large-scale batteries obsess over capex and revenue models. Waratah is a reminder that grid-scale storage is now critical infrastructure, and transformers, protection schemes and local supply chains matter just as much as battery chemistry.
Why this outage matters for Australia’s green energy transition
The Waratah Super Battery isn’t just another BESS project; it’s a keystone in the National Electricity Market (NEM) as coal exits and renewables surge.
A new role for batteries: real-time grid insurance
Waratah sits on the site of the former Munmorah coal-fired power station near Budgewoi. Symbolically and practically, it embodies the shift from centralised thermal generation to flexible, data-driven green technology.
Its job is to:
- Monitor 36 transmission lines in real time
- React in seconds to disturbances on the network
- Provide SIPS services that act as a shock absorber, enabling higher power transfers across the grid without breaching stability limits
In plain language: Waratah lets the system operator run the network “closer to the edge” while staying safe. That’s how you squeeze more value out of existing transmission, integrate more solar and wind, and avoid overbuilding physical wires.
So when that shock absorber is partially offline during the ramp-up to the Australian summer — when air conditioning load spikes and renewable intermittency is front and centre — it sharpens a key question:
How robust is our clean energy infrastructure when single assets carry system-wide responsibilities?
The honest answer: not robust enough yet. And that’s where the lesson for the broader green technology ecosystem comes in.
Technical and supply chain lessons from the transformer failure
The transformer failure at Waratah isn’t just a maintenance story. It’s a wake-up call about how we engineer and support utility-scale storage.
1. Transformers are now climate infrastructure, not a commodity
Main power transformers are notorious for long lead times — 12 to 18 months is typical for manufacture and delivery. For a grid-forming or grid-supporting battery, that’s an eternity.
Waratah has one advantage: its transformers were built by an Australian manufacturer (Wilson Transformer). That local supply means:
- Faster diagnostics
- Local rectification and recommissioning
- Closer technical collaboration between OEM, developer and grid operator
From a green technology perspective, this is a big deal. If your net zero strategy depends on large-scale storage, then local or regional manufacturing capacity for critical components is part of your energy security strategy.
If you’re planning new BESS projects, I’d treat transformer sourcing the way data centres treat backup power and connectivity:
- Prefer regional manufacturing where possible
- Design with spares or modular configurations instead of single, massive points of failure
- Negotiate service-level agreements that reflect the system-critical role of these assets
2. Design for failure, not just performance
Most project decks celebrate peak power, round-trip efficiency, and IRR. Waratah is a reminder that system design needs equally detailed thinking about failure modes.
For utility-scale storage, that means:
- Redundant pathways in transformer and switchyard layouts so a single failure doesn’t halve capacity
- Clear segmentation between SIPS or grid-support functions and merchant or market-facing capacity
- Robust protection and monitoring with AI-assisted analytics to spot early warning signals
In the Waratah case, the battery can still meet its SIPS obligations at reduced capacity. That’s good design. But imagine the impact if the failure had taken the protection function down entirely.
If you’re a developer, ask one blunt question at design review: “What’s our single largest point of failure, and how long does it take to fix if it blows up?” If the answer is “18 months and hundreds of millions in lost value,” you’ve got work to do.
Risk, insurance and finance: how storage projects need to mature
The financial side of Waratah’s outage is just as instructive as the technical side.
The cost of downtime: tens of millions per incident
Current estimates suggest AU$50–80 million in potential losses from the transformer failure, depending on:
- How quickly transformers can be replaced or repaired
- Whether delay-in-start-up coverage applies
- Whether the project is deemed fully operational or still in testing when the incident occurred
For a single event at one project, that’s a large but manageable hit. Scale that across a global pipeline of multi-hundred-megawatt batteries, and you can see why insurers and lenders are reassessing how they look at storage risk.
Here’s where I think the industry is heading — and where smart players will get ahead:
1. Storage-specific insurance structures
Battery projects are not just “another power plant.” They have unique failure modes: battery modules, inverters, transformers, control systems and complex grid integration.
Developers and asset owners should be pushing for:
- Storage-specific wording in policies rather than generic power-asset templates
- Clear treatment of delay-in-start-up vs. business interruption for grid services
- Data-driven pricing based on real asset performance, not just nameplate capacity
2. Data as a risk asset, not a compliance chore
This is where AI and digital tools genuinely change the game.
High-frequency operational data from grid-scale storage — temperatures, harmonics, switching events, fault logs — is incredibly valuable to:
- Flag emerging equipment risks early
- Support claims with hard evidence
- Reduce premiums through proven reliability metrics
If you’re serious about green technology and long-term asset performance, you should be building:
- A unified data platform for all BESS assets
- AI models that learn normal vs. abnormal behaviour for transformers, inverters and battery strings
- Partnerships with insurers who are willing to price risk based on your data quality
The reality? Most fleets aren’t there yet. Waratah is a signal that they’ll need to get there fast.
Where AI fits: smarter, more resilient green infrastructure
Within our Green Technology series, we keep coming back to the same pattern: AI isn’t the star of the show, but it’s the systems engineer behind the scenes.
For assets like Waratah, AI and advanced analytics can materially improve resilience and revenue in a few concrete ways.
Predictive maintenance for critical balance-of-plant
Transformers, circuit breakers and protection systems generate rich data — often underused.
AI models can:
- Detect anomalies in transformer behaviour long before human operators spot them
- Correlate events across the 36 monitored transmission lines and the battery’s own equipment
- Generate ranked maintenance priorities instead of just alarms
That means fewer catastrophic failures, shorter unplanned outages, and better use of planned shutdown windows like the one from 20 November to 2 December.
Smarter operating strategies in high-stress periods
As Australia heads into hotter, more volatile summers, operational strategy matters as much as installed capacity.
AI-based optimisation can:
- Adjust charge/discharge patterns to manage thermal stress on equipment
- Act as a second layer of protection during extreme grid conditions
- Balance SIPS obligations with market participation to avoid over-stressing assets
It’s not about replacing human operators. It’s about giving them tools that see more, faster, across more variables than any control room team can track manually.
What this means for developers, investors and grid operators
The Waratah Super Battery story is a preview of what’s coming as more countries build massive grid-scale storage.
For different stakeholders, the implications are pretty clear.
If you’re a developer or IPP
You should be:
- Treating transformers and protection systems as strategic design elements, not procurement afterthoughts
- Structuring projects so critical services (like SIPS) can survive partial failures
- Investing early in data infrastructure and analytics, not bolting it on at the end
If you’re an investor
You should be probing:
- How projects handle single points of failure and long-lead equipment
- What the insurance stack actually covers — and how delay or performance risk is treated
- Whether there’s a credible AI and data strategy supporting long-term asset health
If you’re a grid operator or policymaker
You should be planning for:
- Redundancy at the system level — not relying on a single “hero asset” to shore up stability
- Incentive structures that reward resilience and availability, not just MW and MWh
- Local supply chain development for critical components as part of climate and energy security policy
The bigger picture: building a resilient green grid
Waratah’s transformer failure is frustrating, but it’s also useful. It exposes exactly where our green infrastructure is strong — fast, flexible, data-rich — and where it’s still fragile — supply chains, insurance structures, and failure planning.
If we treat this as a one-off “technical issue,” we’ll miss the point. If we treat it as a live test of how to design, finance and operate the next wave of utility-scale storage, then projects built in 2026 and beyond will be meaningfully better.
For anyone serious about green technology — whether you’re deploying capital, designing systems, or operating the grid — the question now is straightforward:
Are your storage projects built just to perform, or truly built to fail well and recover fast?
The grid of the 2030s will be shaped by how we answer that now.