APA Fortescue Solar Gas Hybrid Project – Annual Performance Final Report 2024

In 2021 Alinta constructed a 60MWAC Solar Photovoltaic (PV) power station with interconnecting infrastructure in the Pilbara to supply electricity to Fortescue Metal Group’s (Fortescue) Chichester Hub mining operations.

The Project is the first example of large-scale renewables in both low inertia grids and remote mining operations in Australia. The complete power system integrates PV cells, lithium-ion batteries, diesel and gas fired reciprocating engines and gas turbine technologies across five physically distributed locations.

This report details the annual performances of the Chichester Solar Farm (CHSF) for the 2024 period. The report leans on the system forecasting developed during the design stages of the project and compares it to the measured data during the first and second years of operation. The following insights were observed:

• Forecasting of solar yield must include a realistic assessment of inverter downtime, soiling and customer curtailment rates to ensure a high accuracy of expected yield.
• While the system has performed well with the battery energy storage system (BESS), to completely avoid the use of thermal energy for solar operation during cloud cover events, the battery must be of sufficient size in output and energy delivery to ensure that 95% of cloud cover events could be managed.
• The fine dust particles at the project site have an adverse impact on the PCS performance due to the required frequency of the filter maintenance cleaning cycle.
• Washing of panels may not be required depending on rainfall amount and regularity.
• Use of drones fitted with infrared camera technology is an effective method to determine solar panel health.
• The microgrid continues to achieve a high availability even with long transmission lines in a storm prone area.