Group A vs Group B: the main regulatory differences every solar installer in Brazil must master
Confusing Group A with Group B leads to wrong proposals and frustrated customers. Voltage, tariff, demand and modalities — and why they change the whole sizing.
The first question in any Brazilian project should be: "is this customer Group A or Group B?". The answer changes the tariff, what solar offsets, the sizing and even the sales pitch. Confusing the two is a recipe for a wrong proposal and a frustrated customer.
The split is by voltage
The basic criterion is the supply voltage. Group B is low voltage (below 2.3 kV): homes, shops and most rural properties. Group A is high voltage (2.3 kV or more): industries, large commercial buildings, condominiums and larger consumers, usually served through their own transformer.
Single-part vs two-part tariff (and demand)
In Group B the tariff is single-part: you pay only for energy consumed (kWh), plus the tariff flags. In Group A the tariff is two-part: you pay separately for contracted demand (kW) and energy (kWh). This is the point that most affects a solar project: as explained in the guide to sizing for Group A, solar offsets consumption but does not reduce demand.
Subgroups and modalities
Group B is divided into B1 (residential), B2 (rural), B3 (other classes) and B4 (public lighting). Group A has subgroups by voltage (A1, A2, A3, A3a, A4 and AS) and two tariff modalities: Green and Blue, with different treatment of peak and off-peak. Knowing which box the customer is in defines the savings strategy.
Group A vs Group B at a glance
Aspect
Group B
Group A
Voltage
Low (< 2.3 kV)
High (≥ 2.3 kV)
Tariff
Single-part (energy only)
Two-part (demand + energy)
Contracted demand
None
Yes, billed separately
Availability charge
Yes (30/50/100 kWh)
No
Tariff flags
Apply
No (peak/off-peak instead)
Subclasses
B1, B2, B3, B4
A1–A4, AS (Blue/Green)
Typical profile
Homes, retail
Industry, large commercial
Grid connection rules in BrazilDistributed generation, net metering and the role of each tariff group.
What is the difference between Group A and Group B?
Group B is supplied at low voltage (below 2.3 kV) with a single-part tariff (energy only). Group A is supplied at high voltage (from 2.3 kV) with a two-part tariff that bills contracted demand and energy separately.
Do Group B consumers pay for demand?
No. Group B has no contracted demand; consumers pay only for the energy consumed (kWh), plus the minimum availability charge and the tariff flags.
What are the Blue and Green modalities of Group A?
They are Group A tariff structures. Green has a single demand and energy priced at peak and off-peak. Blue contracts peak and off-peak demand separately.
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