Entry · Operation

Hourly load curve

How does consumption vary hour by hour?

● checked against the primary source on Oct 1, 2026Source: ONS

Acronyms: ONS, National Electric System Operator; MMGD, distributed micro and mini generation; SIN, National Interconnected System.

In one sentence

Hour-by-hour electricity consumption profile, published by the ONS by subsystem, in MWavg.

Hourly peak of the SIN load in the day

98,741 MWavg at 19:00Nature of the data: Observed

Sep 28, 2026 · SIN

Source: ONS, Curva de Carga Horária. Reference up to Sep 28, 2026. Captured on Sep 30, 2026.

The hour of highest SIN load in the day, read from the hourly load curve.

Observed: Value published directly by the official or primary source.

It shows at what times the system demands the most energy and when the daily peak occurs.

One value per subsystem and hour: the energy load value, in MWavg.

Unit: MWavg, by hour and subsystem

Energy load
They are the same ONS product at different granularities: the average of the 24 hours of the curve reproduces the load of the day. The curve shows the hour-by-hour profile; the daily load does not.
Global load (verified load)
They are different quantities: global load, by half hour and load area, is above the hourly load curve in the same hours. That is why load net of MMGD is not obtained by subtracting MMGD from the curve.

It includes the ONS estimate of MMGD without separating it.
In the published data, the average of the 24 hours of a day reproduces the daily load (observatory check): it is the same product at another granularity, not an independent source.
Before 2019, on the day daylight saving time began, the hour that does not exist on the local clock comes empty (or zero) and the day has 23 hours.

ONSOpen data portal, dataset “Curva de Carga Horária” (dataset description, accessed on Oct 1, 2026)
Literal excerpt from the document
Portuguese only“Dados de curva de carga horária, que representam o perfil de consumo de energia elétrica com discretização horária.”
ONSData dictionary of the “Curva de Carga Horária” dataset (DicionarioDados_CurvaCarga.json), accessed on Oct 1, 2026
Literal excerpt from the document
Portuguese only“Valor da Carga de Energia, em MWmed”

Documents accessed and text checked on Oct 1, 2026.