Cheap daytime solar is already solved. The hard part in the Pilbara is firm power at 8pm, process steam at midnight, and stability in a weak, islanded grid. That is a duration problem — and it is where concentrated solar thermal (CST) with molten-salt storage earns its place.
The problem is duration, not daylight
Western Australian mining and mineral processing face rising energy costs, a mounting carbon liability, and a long-duration firming gap that short batteries cannot close on their own. The Pilbara produces the overwhelming majority of Australia's iron ore, runs almost entirely on fossil fuel today, and accounts for a large share of the state's emissions. Remote diesel can land anywhere from roughly A$240 to A$450 per MWh.
Daytime photovoltaics are cheap and getting cheaper. But a 24/7 industrial load does not switch off at dusk, and batteries sized for a full overnight block get expensive fast: a battery's cost rises almost in a straight line with the hours it must run.
What CST actually does well
A CST tower concentrates sunlight with a field of tracked mirrors onto a central receiver, heating molten salt to temperatures approaching 565°C. That heat is stored in insulated tanks and released on demand — as firm power through a steam turbine, or directly as high-temperature process heat.
Three properties make it a fit for the Pilbara:
Storage that scales cheaply with duration. Adding hours means adding salt and steel — the cheapest part of the plant — not more chemistry. Eight to fourteen hours of dispatch is standard. Batteries win the sprint of one to four hours; thermal storage wins the marathon.
Synchronous grid strength. The steam turbine spins a synchronous generator, supplying inertia, frequency response and fault current that PV and batteries cannot replicate. In a weak, islanded grid that strength is worth as much as the energy.
Process heat without the round-trip. Stored solar heat can be delivered as high-temperature steam directly, which is cheaper than electrify-then-reheat for many mineral-processing duties.
CST is not the cheapest daytime kilowatt-hour — PV is. For the specific job of firming a 24/7 industrial load and supplying high-temperature heat, nothing else does it more cheaply.
Why now: a proven, operating fleet
This is no longer a demonstration technology. China's tower-CSP fleet represents approximately 1.7 GW across 27 commercial plants as of end-2025 (SolarPACES / CSTA China Blue Book) — grid-connected plants with years of operating data behind them. The engineering risk has been retired somewhere else, at scale. The opportunity now is deployment, not invention.
Where it lands first
The value is highest where a creditworthy host runs a continuous load with real heat demand: lithium processing, alumina refining, rare earths, iron ore and green iron (DRI), remote mine microgrids, and other high process-heat applications. We anchor to that host first, then select the technology configuration once the duty profile is clear. No speculative builds.
Our honest stance
We start every engagement with a no-cost desktop screen that benchmarks CST against PV, batteries, wind, gas and electrification, and returns a clear go / no-go verdict. If PV and batteries serve a site best, we will say so. The point is to put firm, clean power and process heat where it is genuinely the lowest-cost answer — and to be straight about where it is not.
All figures referenced are screening-grade and indicative; not investment advice.