Bluegrass BESS: HV Testing and Commissioning
- Client
- ACLE
- Principal Contractor
- ACLE
- Developer
- X-Elio (Brookfield-backed)
- Asset Owner
- X-Elio
- Location
- Western Downs, Queensland, QLD
- Grid Connection
- 132 kV Chinchilla to Columboola transmission line (Powerlink)
- Capacity
- 60 MW / 120 MWh (Stage 1); Stage 2 adds 88 MW (148 MW total)
- Voltage
- 33/132kV
- Battery OEM
- Narada Power
- PCS-side Switchgear
- Ingeteam (grid-forming PCS)
- Asset Type
- Grid-scale BESS co-located with 200 MW Blue Grass Solar Farm
- Project Type
- BESS commissioning — FAT, SAT, protection, HV cable, earth testing
- Duration
- May 2025 to February 2026
- Megavar Scope
- FAT, SAT, protection commissioning, HV cable VLF testing, HV switchboard testing, 125 Vdc auxiliary system testing, 750 kVA kiosk testing, earth testing
Overview
The Bluegrass BESS, also known locally as the Chinchilla 60 MW BESS, is a 60 MW / 120 MWh grid-scale battery energy storage system located in the Western Downs region of Queensland, approximately 14 km from Chinchilla. Built as Stage 1 of a 148 MW hybrid addition to the operating 200 MW Blue Grass Solar Farm, the project connects into the 132 kV Chinchilla to Columboola transmission line on the Powerlink network. The asset uses Narada Power batteries and Ingeteam power conversion systems, and forms part of the ARENA-supported program to deploy advanced inverter capability, providing inertia and voltage support into the Queensland grid.
Megavar was engaged by ACLE, the head contractor, to deliver the high-voltage testing and commissioning scope across the project’s 33 kV plant. The scope spanned Factory Acceptance Testing, Site Acceptance Testing, protection systems commissioning, HV cable testing, HV switchboard testing, and earth testing, carried out between May 2025 and February 2026. The work covered eight 33 kV feeder bays, a 33 kV incomer, a 750 kVA auxiliary transformer kiosk, and the supporting 125 Vdc auxiliary systems.
Delivering a grid-forming BESS in a remote location, inside an operating solar farm, required close coordination with ACLE’s construction programme and a testing approach that could move in stages as scope was progressively released. The Megavar team combined experienced site-based testers with remote engineering support to keep the job moving at the pace ACLE required.
Scope of Work
- Megavar’s scope covered the full testing and commissioning workflow for the 33 kV switchroom and associated auxiliary systems. The work was released to Megavar in stages to align with ACLE’s construction sequence, and included the following:
- Factory Acceptance Testing on 33 kV ABB ZX2 and 33 kV Siemens 8DA10 switchboard panels prior to site delivery.
Site Acceptance Testing covering the complete installed 33 kV switchgear population once energisation-ready. - Protection systems commissioning, including configuration, secondary injection testing, end-to-end testing and protection setting verification across the installed relay population.
- HV cable testing on 33 kV XLPE feeder cables using Very Low Frequency (VLF) withstand methods.
- HV switchboard testing, including primary injection, timing, contact resistance and insulation testing.
- Commissioning of the 125 Vdc auxiliary system, covering batteries, chargers and the DC distribution board.
- Testing of the 750 kVA auxiliary transformer kiosk.
Earth grid continuity and earth resistance testing, with results documented in a formal Earth Testing Report. - Preparation of FAT and SAT Inspection and Test Plans, test records, and energisation-ready commissioning packs.
HV Switchgear Population Tested
- 2 x 33 kV ABB ZX2 switchboard panels (1 FAT, 1 SAT)
- 2 x 33 kV Siemens 8DA10 switchboard panels (FAT)
- 6 x 33 kV Siemens 8DA10 switchboard panels (SAT)
- 1 x 750 kVA auxiliary transformer kiosk
- 125 Vdc battery bank, chargers and DC distribution board
Protection Relays Commissioned
The project used a modern protection platform. Megavar commissioned the following relay types across line, bus and feeder applications:
- ABB RED 615 line differential relays
- Alstom/GE MiCOM P746 bus differential relays
- ABB REF 620 feeder protection relays
- ABB REX 640 multi-function protection relays
Megavar Test Equipment Deployed on Site
Megavar applied its in-house Omicron-led test fleet across the full testing and commissioning cycle:
- Omicron CMC 356 protection relay test sets with CMGPS 588 satellite-synchronised end-to-end testing units
- Omicron CPC 100 multi-function primary test systems
- Omicron CIBANO 500 circuit breaker analyser and MOM3 micro-ohmmeter
- Omicron CT Analyzer for current transformer performance testing
- Omicron Testrano 600 for transformer testing at the 750 kVA kiosk
- HVA60 and PFT503 50 kV hipot sets for HV withstand and VLF cable testing
- Megger HSW3-2 high-current source and Megger 5 kV insulation testers
- Megger Torkel 930 for 125 Vdc battery bank capacity verification
Standards and Compliance: Testing and commissioning was performed to the relevant Australian Standards and to the project-specific Blue Grass BESS Protection Report, and to ACLE’s approved Inspection and Test Plans. All test records and commissioning certificates were issued against ACLE’s ITP framework.
Challenges and Approach
Commissioning a grid-forming BESS inside an operating solar farm, in a remote Queensland location, on a progressively released scope, creates a different risk profile to a conventional build. Three practical challenges shaped the delivery approach on Bluegrass.
Staged scope release
The testing scope was released to Megavar in stages as ACLE’s construction sequence progressed. This required resourcing plans and test equipment mobilisation to flex across multiple site visits rather than a single campaign. The team worked to ACLE’s release cadence, sizing each visit to complete a usable block of assets rather than stop-starting the programme.
On-site troubleshooting across design, schemes and testing
During commissioning, the team encountered a number of issues spanning design interpretation, protection scheme behaviour and test execution. Megavar diagnosed the root cause in each case and provided a practical path forward, either through test adjustment, scheme refinement or coordination with the design authority. Getting to a clean root cause quickly, rather than working around symptoms, kept the programme moving.
Holding the programme in a remote location
To meet ACLE’s timeline from a remote site, the team worked extended hours with a strong focus on safety and quality. Rigid adherence to the ITP structure meant that the additional hours translated directly into progress on energisation-ready assets, rather than rework later in the programme.
Outcomes
Megavar completed the testing and commissioning scope in line with ACLE’s programme, and the following 33 kV assets were successfully energised following completion of the testing and commissioning work:
- 2 x 33 kV feeders (B01 and B02), extended onto the existing bus in the Blue Grass Solar Farm 33 kV switchroom
- 1 x 33 kV incomer (EB13) in the new Blue Grass BESS Switch Room 1
- 6 x 33 kV feeders (EB11, EB12, EB14, EB15, EB16 and EB17) in the new Blue Grass BESS Switch Room 1
- 1 x 750 kVA auxiliary transformer kiosk
- All works were delivered in line with the project’s Australian safety and quality standards and to the ACLE-approved ITP framework. ACLE’s formal feedback on the testing team’s performance, set out below, is a strong positive signal for repeat engagement on future BESS commissioning work.
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