Energy, Energy comsumption, Power systems

The white tariff system

Today is explained how the Brazilian white tariff system works. This is an alternative form to consumer pay electricity bill.

Why white tariff exists?

In conventional tariff, the consumer pays a determined fixed value, in R$/kWh, charged by energy consumption in entire month, independent of day time. Each state has a different tariff. Bill value includes energy generation cost, transmission cost, sector charges and taxes. However, daily consumption isn`t constant. In residences, it is higher in late afternoon and evening and lower during after midnight. The load curve shows daily consumption in KW, this is a typical load curve of a residence.

residential load curve

This is a commercial consumer`s load curve.

commercial load curve

In January 1st, 2018, those with average consumption above 500 KWh/month could adopt white tariff. In 2019, become available to low power consumers (127, 220, 380 or 440 V) and with average consumption above 250 KWh/month. In 2020, all consumer units can opt for this system.

How it works?

In this system, consumer can pay different values in function of day of the week and day’s time. Exist three types of time:

  • Rush hour (Horário de ponta): When energy demand is the highest, tariff is most expensive.
  • Intermediary hour (Horário intermediário): One hour before and one after rush hour. Cost is cheaper than rush hour, but higher than off-peak.
  • Off-peak hour: When there are low energy demand and tariff is the cheapest.

With white tariff system, can pay less in off-peak hours (white bars in figure below). But will pay more in intermediary and rush hours. The consumer can allocate energy consumption to off-peak hours, reducing overload in electric system. Conventional tariff is the blue line in figure below.

white tariff x conventional tariff

Is white tariff advantageous?

The answer is: Depends on consumption habits. If you can transfer most of consumption to off-peak hour and reduce maximum possible in intermediary and rush hours, white tariff is a good option. Commercial estabilishments and small industries which work until late afternoon, can reduce expenses with energy in white tariff mode. It is necessary to analyze consumption profile and make calculations to see how much economy will generate adopting the new system.


About Pedro Ney Stroski

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