The renewable energy buildout is the largest single category of construction work in the country. Ausgrid’s Hunter-Central Coast REZ at $1B, Snowy 2.0 at $5.1B, TransGrid’s HumeLink, and the wave of grid-scale battery energy storage systems across NSW and Queensland are putting Tier-1 EPC contractors into a tender environment they have not historically priced well. The capital projects are new. The sites they are built on, in most cases, are not.
APA, AGL, Ausgrid, TransGrid, Origin, Jemena, Acciona, Iberdrola and their Tier-1 EPC partners are all running fast on this work. The deals get signed on construction cost. The losses get realised on what was not in the scope — and the most consistent gap, project after project, sits in the demolition and remediation line items that nobody wanted to own at tender time.
Existing Structure Removals on Brownfield Substations
Almost every new substation, BESS site, or grid connection point on the NSW and QLD energy pipeline is being built adjacent to, or directly on top of, existing electrical infrastructure. The 1960s and 1970s substations being decommissioned to make way for new switchgear carry a stack of removal costs that rarely make it into the EPC tender response: the original concrete plinths, the bunded oil containment, the porcelain and ceramic insulators, the legacy oil-filled transformers, and the soil that sits underneath all of it. The civil contractor inherits the lot, and the head EPC inherits the program risk.
The Hazardous Materials Inventory Nobody Updates
Legacy substations and grid infrastructure contain hazardous materials that are not always documented to current standards. PCB-containing transformer oils, asbestos lagging on switchroom pipework, lead-based paint on structural steel, and SF6 gas in older gas-insulated switchgear all sit on assets that have been quietly maintained for decades. The original hazmat register, if it exists, is rarely complete. The cost of disposal, the licensing of the contractor doing the removal, and the time required for compliant decommissioning are routinely missed in the EPC scoping documents. When discovered on site, every one of them stops work.
Civil Rehabilitation on Solar Farm and Wind Sites
The civil rehabilitation obligation on solar farm and wind project sites is the most underpriced line item in the entire renewable EPC market. Pile holes from temporary works, access track removal, topsoil reinstatement, drainage repair, sediment basin decommissioning, and re-vegetation under landholder agreements all sit on the contractor at handover, not at commissioning. The tender response that does not separate civil rehabilitation from construction civils is the one where the rehabilitation cost gets eaten by the construction budget — and the contractor finishes the project with a rehab obligation and no money left to deliver it.
BESS Site Surprises — The Bund and the Compacted Fill
Grid-scale battery sites sit on engineered pads with bunded containment, fire separation, and access roads designed for very high axle loads. The remediation problem on BESS work is in the ground preparation. Sites that look open and flat at tender often sit on fill that was placed without certification, on soils that present saline or sulfide concentrations, or on legacy industrial pads that contain buried services nobody mapped. The EPC contractor that has not specified a confirmatory geotechnical and contamination assessment before construction starts is the one that absorbs the discovery on day one.
What the EPC Scope Wording Needs to Do
The scope wording on an EPC tender for REZ, BESS, or wind work needs to do four things that standard templates do not. First, separate demolition and remediation from construction as discrete priced items, with their own provisional sums and contingency. Second, specify the hazmat assumptions made at tender — by material, by quantity, and by reference to a named investigation report. Third, ring-fence civil rehabilitation as a separate scope of works, with a defined trigger for when the obligation transfers to the contractor and when it transfers back to the asset owner. Fourth, set a clear variation mechanism for any condition that was not reasonably discoverable from the documents provided at tender.
A One-Pager Worth Putting in Every Bid
Tier-1 EPC bid managers running renewable energy tenders should be carrying a single-page scoping checklist into every pricing review. The list is short — existing structure removals, hazmat in legacy electrical assets, civil rehabilitation, ground conditions, and waste classification — but each line on it has cost a major EPC contractor a seven-figure variation at some point in the last three years. The discipline of using it is the difference between the EPC partners who keep getting awarded the next project and the ones who do not.
The Scope Nobody Wants to Own
Demolition and remediation is the scope nobody at tender table wants to own. The asset owner wants it transferred to the contractor. The contractor wants it carved out as a provisional sum. The civil subcontractor wants it priced by the demolition specialist. In the end, the head EPC owns the risk regardless of how the contract is structured, because the program impact of getting it wrong sits on the EPC’s schedule. The contractors who win the next decade of renewable energy work are the ones who treat that risk as a discipline at procurement, not a fight at handover.
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