Build photography
From factory floor to red-earth site.
Indicative imagery from the TPC delivery library. Site-specific photography is shared with qualified counterparties on request.
A 12 MWp single-axis tracking PV plant paired with 24 MWh of LFP storage forms an island-capable microgrid for a remote Pilbara mine site — running grid-forming through every solar hour, dropping the on-site diesel station to standby for ~9 hours a day, and saving an estimated 6.4 million litres of diesel a year.
The site is a remote Pilbara mine, ~1,400 km road-haul from Perth, with a contracted electrical baseline of ~17 MW continuous (peak ~24 MW) — comminution circuit, haul-truck workshop, accommodation village, water treatment, communications, and the perimeter security envelope. Pre-project the entire load was carried by an 11-set diesel station burning around 11.5 ML/yr at delivered cost north of A$1.55/L.
Three structural problems compounded: fuel logistics (each tanker convoy is a road-train movement booked weeks ahead, and one cyclone closure of the Great Northern Highway disrupts the entire month's schedule), diesel station de-rate at 45 °C ambient (real-world output from the rated nameplate sits 7–9 % lower than catalogue, eaten by parasitic cooling), and operator decarbonisation commitments tied to the parent company's Scope 1 target — every tonne of diesel CO2e on site is counted directly against the target.
The brief was demanding: be diesel-off every solar hour the weather permits, survive a cyclone-rated wind load (region D, 270 km/h gust), and integrate with the existing diesel station as a master controller — never as an auxiliary.
A typical mining solar add-on bolts a PV array onto an existing diesel station as a fuel-displacing auxiliary, leaving the diesel governor as plant master. The Pilbara brief inverted that hierarchy: the BESS is the system master through every solar hour, holding the bus voltage and frequency in island mode while the diesel station drops to hot-standby. Diesel sets only re-enter the bus when forecast solar is insufficient, when weather closes the array, or when load exceeds the BESS PCS rating.
Three engineering decisions diverge from a typical mine-solar retrofit:
A common 33 kV bus carries every source and every sink: trackers, BESS, diesel station, and the mine's process and accommodation feeders. The BESS PCS is the master frequency reference through every solar hour; the diesel station picks up the bus when the BESS hands off, never the other way around.
Component selection is illustrative — final BoM in any binding TPC delivery is calibrated to mine power-system study, AS/NZS 4509 stand-alone power system requirements, AS 1170.2 wind region, and the EESS-approved inverter list current at quote time. Primary equipment ships factory-direct; site civils, piling, MV cabling, and HV scope are procured locally under TPC engineering supervision.
| Component | Specification | Qty | Source |
|---|---|---|---|
| PV module | N-Type TOPCon bifacial double-glass · 590 W · 132-cell · IEC 61215 / 61730 / 62804 | 20,340 | Factory-direct |
| Single-axis tracker | Distributed row architecture, ±60° tracking, cyclone-rated stow, battery-backed controller per row, AS/NZS 1170.2 region D | 282 rows | Factory-direct |
| Driven pile foundation | Steel C-section, hot-dip galvanised, 4.0 m, geotech-tested embedment for Pilbara red-earth pisolitic soils | 3,950 | Site-procured |
| String inverter | 1500 V DC · 350 kW utility · IEC 62109 · IEC 61727 · IP66 · −25 to +60 °C, AS/NZS 4777.2 listed | 36 | Factory-direct |
| MVPS skid | Pre-fab MV station: string inverter mount, 6 MVA dry-type 33 kV pad-mount transformer, MV switchgear, auxiliary AC/DC | 2 | Factory-direct |
| LFP battery containers | 40-ft outdoor container · 6 MWh per container · liquid-cooled · UL 9540A · IEC 62619 · AS/NZS 5139 | 4 | Factory-direct |
| Grid-forming PCS | 8 MW continuous / 16 MW 90-second overload · IEEE 2800 · virtual inertia & short-circuit current support · AS/NZS 4777.2 | 2 | Factory-direct |
| 33 kV ring main unit (RMU) | SF6-free vacuum-break · IEC 62271-200 · 24 / 36 kV · 630 A bus, mine-bus tie scheme | 8 | Factory-direct |
| Plant controller / SCADA | IEC 61850 · forecast-aware solar dispatch · diesel coordination · AS 4509 SAPS-compliant logic, lender-grade reporting | 1 | Factory-direct |
| Cyclone-rated tie-down | Engineered tie-down system to AS/NZS 1170.2 region D · 270 km/h gust, validated stow position windload | 1 lot | Site-procured |
| Robotic dry cleaning | Autonomous dry-brush units per tracker row, IoT telemetry, off-cycle nightly run | 282 | Factory-direct |
| HV / MV cabling | 33 kV XLPE armoured, 1500 V DC PV string cable, fibre-optic SCADA, AS/NZS 1429 / IEC 60502 | ~38 km | Site-procured |
| Civil & security | Bulk earthworks, perimeter security with thermal CCTV, gravel access road, BESS pad with NFPA 855 setback, control building | 1 lot | Site-procured |
| Diesel station integration | Mine power-system study, generator governor retune, master-slave handoff logic, witness sign-off | 1 package | TPC engineering |
| Commissioning & performance test | FAT + SAT + AS 4509 commissioning + 14-day capacity test + 12-month diesel-saved monitoring + lender-grade reporting | 1 package | TPC engineering |
Monthly generation is computed from public NASA POWER irradiance for ~22°S Pilbara, applied to the as-designed single-axis tracker spec at PR 0.78 with bifacial gain 1.06. Note the southern-hemisphere profile — peak in October / November, trough in May / June. Hover any bar for the underlying figure.
Cyclone season (Dec–Mar) introduces single-day generation losses when trackers are stowed pre-cyclone — captured in the modelled monthly figures via a 4-day annual stow-loss budget. The June trough is the binding case for diesel re-engagement: at ~1.40 GWh/month and 17 MW continuous load, BESS-only midday operation requires ~85 % of solar production hours with no cloud cover. The +18 % tracker uplift over fixed-tilt is what makes the diesel-off operating mode tractable through the southern-hemisphere winter.
Auxiliary-mode solar add-ons cap renewable penetration at ~25–30% because the diesel governor cannot release the bus. Specifying the BESS PCS as grid-forming master from day one — with the diesel station retuned for slave-follower operation — is what makes 9 hours/day of diesel-off operation achievable. It is a power-system architecture decision, not a procurement decision.
The trackers can structurally survive 270 km/h gusts at 0° stow — provided every single row reaches stow before the gust front arrives. Battery-backed row controllers and a forecast-fed pre-emptive stow trigger from the BoM cyclone watch feed are non-negotiable; comms-loss-fail-to-stow is the design rule. Two independent wind anemometers per tracker block keep the controls honest.
The financial model carries a 6.4 ML/yr direct fuel saving — a real number. The bigger commercial outcome rarely shown on the lender model is the resilience win: one cyclone-closed Great Northern Highway becomes a non-event for the mine when the BESS has 3 hours of bridging energy and the diesel station has its full pre-cyclone stockpile untouched. The fuel saved pays for the asset; the resilience pays for the mine plan.
Indicative imagery from the TPC delivery library. Site-specific photography is shared with qualified counterparties on request.
The day the diesel station went to zero output for the first time, the comminution circuit kept turning, the air-conditioners in the village kept running, and the haul-truck workshop didn't notice. That is the only way you know the BESS is the master and not an aspiration. From that morning, every solar hour the weather permits is a diesel-off hour — and that is what removes diesel-logistics risk from the mine plan, not what saves the litres on the invoice.Mine power systems lead · microgrid commissioning · TPC engineering
Quote is illustrative of the engineering posture TPC brings to remote off-grid mine microgrid engagements. This reference design is not tied to a named or contracted client; site-specific testimonials are released only with the operator's signed consent.
Mine microgrid, remote off-grid hybrid, or grid-forming BESS for an industrial load — TPC's engineering team will scope the same equipment envelope for your project under a one-business-day SLA.