Curtailment — being told to turn down or switch off — is climbing across Australia’s grid as renewables surge faster than transmission and system-strength upgrades.

Why Curtailment is Rising

Daytime oversupply & negative prices: Q2-2025 saw a record share of negative/zero price intervals (10.6% of all dispatch intervals; SA & VIC hit 34%/27% of daytime intervals). That’s classic curtailment territory.
Congestion & system strength limits: These are particularly acute in western NSW and northwest VIC, with AEMO’s 2025 forecasts flagging rising locational curtailment risk.
Not just theory: Curtailment averaged ~4.5% in 2024, with several utility-scale sites experiencing >25%. For new builds in the south-east, curtailment could reach 35–65% by 2027 without timely transmission upgrades.

What Does Curtailment Cost Per 100 MW?

Let’s take a 100 MW (AC) solar farm at a modest 28% capacity factor:

Generates ~245,000 MWh/year.
If 5% is curtailed, that’s ~12,250 MWh lost.
At recent NEM average spot ~A$140/MWh plus LGCs ~A$20/MWh, the value is ~A$160/MWh.
That equals ~A$2.0 million/year lost at 5% curtailment.
At 25% curtailment (which some plants saw), the lost revenue approaches A$9–10 million/year.

Rule of thumb: Every 1% curtailed on a 100 MW solar farm = A$0.38 – A$0.45 million/year in foregone energy + LGC value at today’s ranges.

How Curtailment Impacts Drone Thermography

Curtailment doesn’t just hurt revenue — it also disrupts O&M inspections.

Drone thermography requires energised strings. Non-energised blocks can’t be assessed to IEC-aligned standards. That means waiting, rescheduling, or re-flying when export is limited or the plant is partially offline.

Operational impact per ~100 MW inspection:

Baseline scope (RGB + thermal + analytics) for ~100 MW typically budgets 2–3 field days plus post-processing.
Curtailment-driven delays (stop-start windows, partial energisation) commonly add 0.5–1.5 extra field days and can force re-visits.
Using typical Australian crew economics (two-person crew, travel, aircraft/thermal payload, insurance, analytics): A$8k–A$15k baseline per 100 MW can swell by +25–40% (A$2k–A$6k) with one extra field day and/or a re-visit.
Cascade effect: every extra day lost to curtailment is a day operators aren’t scanning the next site — real opportunity cost for both the asset owner (later findings/remediation) and the operator (lost billable day).

Batteries as a Solution

Curtailment is not inevitable. Co-located battery energy storage systems (BESS) provide a practical fix:

Store midday surplus, sell into evening peaks: Batteries lift revenue by arbitraging from negative/low daytime prices to higher evening prices.
Reduce curtailment exposure at the node: Co-located BESS soaks up congestion-driven surplus, smoothing export, and keeping arrays energised for reliable thermography windows.
Longer-duration storage is arriving: Projects like Limondale’s 8-hour battery highlight the shift from 2–3 hour to multi-hour firming, unlocking more curtailed energy and resilience.

Back-of-envelope for a 100 MW solar farm:

At 5% curtailment (~12,250 MWh/year lost), diverting even half of that to a co-located battery and selling at a conservative A$120–A$160/MWh yields A$0.7–A$1.0 million/year recovered (before FCAS/other services).
Add FCAS and congestion-relief benefits (reduced negative-price exposure, improved capture rates), and ROI improves further — explaining why battery pipelines are accelerating.

Skyspec Drone Services + Sitemark: Delivering Smarter Inspections

Curtailment also inflates the cost of thermography. That’s where the Skyspec + Sitemark partnership makes a difference.

Sitemark offers a comprehensive solar management platform — not just thermography. Their Fuse platform creates a digital twin of the site, integrates defect analytics, and manages work orders in one system. It automates inspections, integrates GIS data, and allows O&M teams to track corrective actions over time.

Importantly, Sitemark optimises drone flight paths for efficiency. Instead of flying sideways across rows, drones fly forward along panel strings. This speeds up inspections while still capturing 100% of modules, even on single- and dual-axis tracker sites. Panels don’t need to be set horizontally, and the software still produces high-quality orthomosaics and analytics.

Skyspec Drone Services, in partnership with Sitemark, brings this to Australia. Together, they offer asset owners a turnkey package: skilled drone inspections + Sitemark’s AI-powered analytics + integrated reporting. That means fewer delays, faster results, and more reliable O&M planning — even in the face of curtailment.

Takeaway

Curtailment is a rising, location-specific tax on solar revenue — and it also inflates O&M costs by disrupting drone thermography windows. Batteries transform wasted energy into revenue and stabilise operations. And by leveraging partnerships like Skyspec Drone Services and Sitemark, solar farm operators can minimise inspection delays, reduce costs, and maximise asset performance.

References

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