The Duck Curve and Your Solar Feed-in Tariff: Related but Different

The duck curve describes a pattern in electricity demand remaining on the grid as solar production rises and falls. It helps explain why sunny midday conditions can differ from the evening, but it is not your household tariff.

For a solar owner, the practical lesson is to understand timing while still checking the actual retail offer. A grid-wide diagram cannot calculate your next electricity bill.

What the curve is showing

Homes keep using electricity during the day. Rooftop solar supplies part of that demand locally, reducing the amount the wider system needs to deliver at that moment.

When solar output is strong, the remaining grid demand can dip. As sunlight fades and household activities continue, demand supplied through the grid can rise again.

AEMO's explanation of minimum operational demand describes how high rooftop solar output can coincide with low demand on the grid.

Its historical examples illustrate the concept; they are not presented here as current demand records or forecasts.

The dip does not mean people stopped using electricity. It means the source serving some of their demand changed. That distinction matters when reading charts labelled operational or underlying demand.

Why it can matter for prices

Electricity market conditions reflect supply, demand and the ability to move or store energy. A period with abundant solar can have different wholesale conditions from an evening with little solar output.

Weather, outages, other generation, transmission and demand all influence the result. The curve is not a promise that every midday interval will be cheap or every evening interval expensive.

Your own solar generation follows the roof, weather and system design. It is only one small part of the broader system described by a market-demand chart.

Avoid reading the height of a demand curve as a feed-in price. Demand and price have different units, and a relationship between them does not make them the same measurement.

Your feed-in offer is a separate agreement

A retail offer may use a flat export rate, time-varying rates or a different specified calculation. Read the conditions that apply to the electricity you actually export.

Victorian feed-in guidance explains the role of retailer offers.

Do not use an old regulated rate, another state's rule or a wholesale screenshot as a substitute for your current contract.

Our export-limit guide covers another separate issue: the electricity your connection is allowed to export. Permission to export and the price paid are different decisions.

A high headline feed-in rate can still sit beside relatively costly imports or supply charges. Compare the whole bill using your consumption pattern before choosing an offer.

What a household can sensibly change

Imagine a home with spare midday solar and a dishwasher that can safely finish before dinner. Moving that existing task may increase direct solar use without changing how much washing the household needs.

An EV absent all day cannot use that same opportunity without a different charging arrangement. A household needing heat before sunrise still needs an appropriate source then.

Battery storage can shift some electricity into later periods, but capacity, losses, control terms and cost matter. A duck-shaped chart is not a financial case for every battery.

Hot-water timing is another option where the equipment supports it. Our heat-pump timer guide explains why adequate water and safety settings remain essential.

Keep the system story and household decision connected

Use the duck curve to understand why timing matters. Use your meter data, solar records and current tariff to decide what a timing change is worth at home.

First identify existing flexible loads. Then check whether moving them displaces imports, forfeits export credits or changes other charges. Do not manufacture demand merely to absorb surplus electricity.

A sensible schedule should still meet comfort, transport and hot-water needs on cloudy days. Review it as seasons and the household change.

If the current arrangement already suits your needs, the existence of the duck curve alone is no reason to replace equipment. Better information about the household is the useful next step.