A 300MWh hybrid battery, wind, and solar system is transforming a WA gold mine into a template for low‑carbon, low‑cost industrial energy. Here’s why it matters.
Most people still think heavy industry and clean energy don’t mix. A 24/7 operation like a gold mine is supposed to need diesel, gas, and a lot of it.
Zenith Energy and Northern Star Resources are quietly proving that idea wrong.
In Western Australia’s Goldfields, they’ve signed a 25‑year power purchase agreement (PPA) to build what’s set to be Australia’s largest renewable energy project dedicated to a single mining operation: a 138MW solar farm, 256MW of wind, and a 138MW/300MWh battery energy storage system (BESS), plus 120MW of thermal generation backing it up.
This matters because it shows, in one project, how green technology can decarbonise one of the hardest sectors to clean up while still delivering the reliability and cost certainty investors care about.
In this article, I’ll break down what’s actually being built at Kalgoorlie, why the 300MWh hybrid storage system is such a big deal, and what this model means for anyone planning large-scale clean energy or industrial decarbonisation projects.
A 25‑Year Hybrid Power Deal: What’s Really on the Table?
The Zenith–Northern Star deal is straightforward on paper: Zenith funds, builds, owns, and operates the energy infrastructure; Northern Star buys the power on a long-term PPA. The details are where it gets interesting.
The hybrid renewable hub will include:
- 138MW of solar PV
- 256MW of wind
- 138MW/300MWh BESS
- 120MW of thermal generation (under a separate but parallel 25‑year agreement)
- 132kV transmission network and substations connecting to Kalgoorlie Consolidated Gold Mines (KCGM)
Northern Star expects more than 70% of its Kalgoorlie electricity demand will eventually be met by renewables from this system.
Here’s the thing about that 70% figure: it’s not just a climate win. It’s a hedge against long‑term fuel price volatility, grid constraints, and tightening emissions regulations. For a mine with a multi-decade life, a 25‑year PPA tied to on-site renewables is essentially an insurance policy on energy costs.
From a green technology perspective, this is a textbook example of “electrify what you can, decarbonise the electrons, then add storage to make it reliable.”
Why the 300MWh Battery Is the Project’s Real Engine
The 138MW/300MWh battery energy storage system is what turns a big renewables build into a usable, mine-ready power system.
At this scale, the BESS can:
- Shift solar and wind output into evening and overnight mining operations
- Provide fast frequency response and grid stability services
- Reduce spinning reserve requirements from thermal generators
- Cut fuel burn and wear‑and‑tear on engines by smoothing load and generation
To put 300MWh into context:
- It’s larger than many standalone utility BESS projects.
- It comfortably sits among Australia’s biggest mining‑focused batteries, comparable to Fortescue’s 250MWh deployment.
For a remote, energy‑hungry operation like KCGM, batteries are no longer a “nice to have” addition. They’re the control layer that lets an operator run a high-renewables power system without sacrificing uptime.
How hybrid storage changes mine economics
From the mine’s perspective, the battery:
- Reduces fuel costs: more of the load is met with “free” solar and wind energy, stored and dispatched when needed.
- Flattens price risk: PPA pricing tied to a largely fixed‑cost renewable asset is far more predictable than diesel or gas.
- Protects production: when your revenue depends on continuous crushing, milling, and processing, the cost of a power outage is enormous. Storage dramatically lowers that risk.
For developers and investors, hybrid BESS projects like this are compelling because they open multiple revenue and value streams: PPA payments, ancillary services, capacity value, and long‑term offtake security.
PPAs as the Decarbonisation Backbone for Heavy Industry
This project leans on a model that more industrial players should be copying: long‑term renewable PPA plus private infrastructure ownership.
Under the structure here:
- Zenith Energy: funds, builds, owns, and operates the power assets for 25 years.
- Northern Star: commits to buy power under a long‑term PPA, without needing to own or run energy assets.
The reality? Most mining companies don’t want to become power utilities. They want:
- Stable, predictable power prices
- Low operational risk
- A credible decarbonisation story for investors and regulators
A PPA backed by a hybrid renewable plus storage system ticks all three.
Why this PPA model works so well for green technology projects
For other operators, whether in mining, minerals processing, or heavy industry, there are a few practical lessons buried in this deal:
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Avoid capex shock
Instead of paying upfront for a solar farm or battery, you buy clean energy as a service. The developer carries the capex and optimisation risk. -
Align contract length with asset life
A 25‑year term matches both the mine’s life and the useful life of the energy assets. Short PPAs rarely support this kind of build-out. -
Design for hybrid from day one
Renewables, storage, thermal, and transmission are being planned as an integrated system. Retrofitting storage later is always more painful. -
Use PPAs to drive genuine emissions cuts
A high‑renewables share (70%+) forces serious thinking about storage size, dispatch strategy, and operational flexibility. That’s where the real decarbonisation happens.
For developers and financiers in the green technology space, this is exactly the kind of anchored, contracted project that attracts capital right now: long‑dated offtake, real assets, real emissions reductions.
Fast-Deploy Solar: Why 5B’s Maverick Arrays Matter
Zenith’s solar component will use 5B’s Maverick prefabricated solar array system, and that detail says a lot about how project teams are thinking.
Instead of traditional stick‑build solar farms that require lots of on‑site labour, racking, and complex logistics, Maverick arrays are factory‑assembled blocks of panels that can be unfolded and installed rapidly.
On a remote mining site, that’s a big deal:
- Less time on site in harsh, remote conditions
- Lower construction risk and fewer weather delays
- Reduced workforce requirements where labour is scarce and expensive
- Smaller disturbance footprint, which helps with environmental approvals and local community impacts
This is what modern green technology actually looks like in the field: not just cleaner power, but cleaner, faster, more modular ways of building the assets themselves.
It also ties in neatly with Australia’s push to grow local solar manufacturing and deployment capability. 5B’s role here isn’t just supplying hardware; it’s building a template for how large off‑grid and fringe‑of‑grid renewables can be rolled out at industrial scale.
From One Gold Mine to a Blueprint for Net‑Zero Operations
The KCGM project isn’t just another “mine adds solar” headline. It’s a blueprint for how high‑demand, remote operations can transition away from fossil fuels while keeping the lights – and the mills – fully powered.
Zenith’s managing director, Hamish Moffat, summed it up neatly when he described the system as:
“Cost‑effective, clean, scalable, reliable and delivery of tangible benefits to local and regional communities.”
That combination is exactly what every serious decarbonisation project should be aiming for.
If you’re responsible for energy strategy, sustainability, or capital planning in a resource‑ or energy‑intensive business, here’s how this model can translate into your world.
Practical steps for organisations planning similar projects
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Map your load and mine/plant life honestly
Long‑term PPAs only make sense if you understand how long you’ll be operating and how your load may change. -
Start with an integrated energy concept, not a single tech
Don’t just “add solar” or “add a battery”. Model a full hybrid system: renewables, storage, backup thermal, and the grid connection. -
Use storage as the flexibility layer, not an afterthought
Size and specify the battery around operational needs: ramp rates, outage tolerance, shift patterns, and process criticality. -
Structure your PPA to reward decarbonisation
Include clear performance metrics around renewable share, availability, and emissions intensity, not just price per MWh. -
Engage early on approvals and community impacts
Projects of this scale touch land use, biodiversity, noise, and cultural heritage. Early engagement reduces delays and cost risk.
As we close out 2025 and look toward 2026, projects like this are setting expectations. Investors and customers increasingly assume that green technology plus smart contracts is the default for new industrial energy systems, not an experiment.
The reality: if a massive open‑pit gold mine in the WA Goldfields can aim for 70% renewable power backed by a 300MWh battery, most other large operations are out of excuses.
Now is the time to decide whether you want to be buying fossil‑heavy power in 2040, or telling your board you locked in clean, predictable energy back in the mid‑2020s when the opportunity was still wide open.