How can Group A consumers be billed as Group B?

Updated October 15, 2025

Did you know that some consumer units in group A can be billed as if they were in group B?

This framework can generate significant savings and greater viability for distributed generation projects. In this article, we explain in which situations this is possible according to Resolution 1.000/2021 (Normative Resolution No. 1000/2021) and what to consider when designing a photovoltaic system in these cases.

Electricity consumers can be classified into two groups: A or B. Group A (high voltage) consists of CUs (consumer units) that receive electricity at a voltage equal to or greater than 2,3 kV or are served by an underground distribution system. This group generally includes large industries and large commercial establishments.

Group B (low voltage) is characterized by CUs served at a voltage lower than 2,3 kV, generally with a monomial tariff, proportional only to consumption, with no demand charges. This category generally includes residences, small industries, and small commercial establishments.

A Resolution 1.000/2021, which deals with the general conditions of electricity supply, determines the criteria for a CU to be classified as Group A or Group B. In general, they meet both requirements. These are:

• Group B: CUs served by an overhead network, when the installed load is equal to or less than 75 kW;
• Group A: CUs served by underground networks, or overhead networks with an installed load greater than 75 kW.

Resolution 1.000/2025 also provides that a consumer unit in Group A may choose to be billed as Group B (without having to pay the billable demand), as long as it meets at least one of the criteria below:

• The sum of the nominal powers of the consumer unit's transformers is less than or equal to 112,5 kVA;
• The sum of the nominal powers of the consumer unit's transformers is less than or equal to 1.125 kVA, if classified in the rural electrification cooperative subclass;
• The activity carried out in the consumer unit is the operation of hotel or guesthouse services and is located in a summer or tourism area, regardless of the total nominal power of the transformers; or
• The installed load of the reflectors used for lighting is greater than or equal to 2/3 of the total installed load in permanent installations for sporting activities or agricultural exhibition parks.

If the option to bill as Group B is made, there will be no need for physical changes to the facilities, and the consumer unit will continue to be served at high voltage, from its private distribution transformers.

The change will only affect the way this consumer unit is charged for energy, with a monomial tariff, not paying for billable demand. For consumer units that have a photovoltaic generator installed, such a change, when possible, increases their profitability, as this customer will no longer pay for billable demand, potentially reducing their energy bill to the minimum availability cost.

Conclusion

The possibility of billing Group A units as Group B may represent an opportunity for consumers to reduce fixed demand costs. However, this decision requires careful technical analysis. If you work in the photovoltaic sector, understanding these rules is essential to offering the best solution to your customers. To learn more, check out our solar power plants course.

Deepen your knowledge

[elementor-template id="561643″]