The Duck Curve? Related to Duck?
- EcoVision
- Jan 25
- 3 min read
A Solar Success Story—and a Wake-Up Call for APAC Energy Planning (and ESG)
If you’ve been following the clean-energy transition, you may have heard the term “duck curve.” It sounds casual, but it describes a very real operational challenge that shows up when a power system adds lots of solar PV in a short period of time—something many APAC markets are actively doing.
What is the duck curve?
The duck curve is a chart of net load—the electricity that the grid must supply after subtracting renewable generation (especially solar).
As solar grows, the curve often starts to look like a duck:
Midday (“belly”): Solar production is high, so net load drops. The grid needs less power from conventional sources.
Late afternoon to evening (“neck”): Solar output declines quickly as the sun sets, but demand often rises (air-conditioning, lighting, cooking, commuting patterns). Net load then ramps up fast.
This isn’t a problem caused by renewables “not working.” It is a system-planning signal: as solar scales, the grid needs more flexibility to balance supply and demand through the day.
The term became widely used after the California Independent System Operator (CAISO) published a chart showing this shape as solar penetration increased.
Why the duck curve matters in APAC
APAC is diverse: some markets are mature and liberalised; others are still building basic grid capacity. But across the region, several shared trends make the duck curve increasingly relevant:
Rapid solar build-out
From utility-scale projects to rooftops, solar capacity is expanding across parts of Southeast Asia, Australia, India, and beyond. That midday solar surge can push net demand down sharply.
Peak demand often arrives after solar fades In many APAC cities, the highest demand hits in the evening (residential activity + lingering cooling demand). That creates the steep ramp. (the neck)
Grid constraints and congestion are real Some regions face transmission bottlenecks, limited interconnection between provinces/states, or constrained reserve margins. Even with plenty of clean generation on paper, getting electricity to where it is needed—at the right time—can be hard.
Energy security is a board-level topic Geopolitical risk, fuel price volatility, and climate extremes are bringing energy reliability into corporate risk discussions. The duck curve is one practical lens for talking about reliability during decarbonisation.
How this connects to ESG and sustainability
The duck curve sits right at the meeting point of “E,” “S,” and “G”:
Environmental (E): Solar reduces emissions, but high midday output can lead to curtailment (turning down renewables) if the system cannot absorb it. Fixing the duck curve improves the utilisation of clean energy and accelerates real emissions reductions.
Social (S): Reliability affects people first. If grids cannot handle evening ramps or heatwave peaks, communities face higher outage risk and price stress. A transition that keeps the lights on is also a transition that supports livelihoods.
Governance (G): Transition plans are increasingly evaluated on credibility: Are targets matched with operational plans, capex, and risk management? The duck curve is a concrete example that “buying renewables” is necessary, but not sufficient.
What solutions flatten the duck curve?
Here are practical tools that many APAC systems are already prioritising:
Battery energy storage: store midday solar, discharge during evening peaks. This directly reduces ramp pressure.
Demand response and load shifting: move flexible demand into solar-heavy hours (industrial scheduling, chilled water systems, smart buildings.. especially via the advance AI technologies these days)
EV charging strategies: workplace and fleet charging during the day can absorb solar generation; unmanaged evening charging can worsen the ramp.
Grid upgrades and interconnectors: stronger transmission and regional interconnection smooth variability and share reserves.
Flexible generation and firm low-carbon supply: hydro (where available), geothermal, and other dispatchable resources can support the evening transition.
Market design and tariffs: time-of-use pricing can encourage consumption when clean energy is abundant and cheaper.
For additional reference reading, can refer to our green blog:
"Grid Innovation? Backbone for clean energy transition"
What this means for businesses in APAC
For companies pursuing net zero, the duck curve changes the question from “How much renewable energy did we procure?” to “How well does our clean-energy strategy match grid needs and emissions impact?”
A few business-relevant actions:
Explore time-matched clean electricity approaches (where feasible), not just annual matching.
Add storage to on-site solar for resilience and peak management.
Shift discretionary loads (cooling, pumping, charging, batch processes) into midday periods.
When structuring PPAs, consider products that support firming or shape delivery profiles.
Bottom line
The duck curve is a sign that solar is scaling—good news for decarbonisation.
But it also shows that the next phase of sustainability leadership in APAC will be about system solutions: flexibility, storage, demand management, and grid investment.
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