The expansion of distributed solar generation in Brazil has profoundly altered the relationship between consumers, distributors, and the electricity grid. With the enactment of Law No. 14.300/2022, the sector began to operate under a new legal framework for electricity compensation, replacing the old perception of "full compensation without grid usage costs" with a more complex model guided by the logic of remuneration for distribution infrastructure.
In this context, one of the discussions that has been gaining practical relevance is the possibility of charging the TUSDg (Transmission System Usage Tariff) on consumer units in Group B (microgeneration), especially those with photovoltaic systems connected at low voltage.
Legal basis for charging the TUSDg fee.
The controversy surrounding the collection of TUSDg (Transmission System Usage Tariff) from Group B consumer units (microgeneration), especially those with photovoltaic systems connected at low voltage, is not trivial.
For years, the regulatory discussion regarding grid use has focused on the so-called "B wire" charge levied on compensated energy.
However, the regime established by Law No. 14.300/2022 and regulated by ANEEL It also began to allow, under certain circumstances, charges related to power injection into the grid, a topic that requires careful reading of the regulation, lest one confuse compensated energy, surplus energy, and generation demand.
The central point, therefore, is not only whether a charge exists, but under what legal and technical conditions it can occur. The first normative basis for the charge is found in Article 18 of Law No. 14.300/2022[1], as follows:
Art. 18. Free access to the distribution system for units with microgeneration or distributed minigeneration is guaranteed, upon reimbursement, by consumer units with distributed minigeneration, of the transportation cost involved.
Sole paragraph. In establishing the transportation cost, the tariff corresponding to the form of use of the distribution system carried out by the unit with microgeneration or distributed minigeneration must be applied, whether to inject or consume energy. (BRAZIL, 2022).
Therefore, barring any better interpretation, the article ensures free access to the distribution system for units with microgeneration or distributed minigeneration, upon reimbursement of the transportation costs involved.
The sole paragraph of Article 18 stipulates that, in establishing this cost, the tariff corresponding to the form of use of the distribution system must be applied, whether for consumption or for injecting energy.
In legal terms, this means that the law has come to expressly recognize that the use of the grid is not limited to the consumption of energy from the distributor: it can also result from the use of the infrastructure to transport energy generated by the consumer unit itself.
At the sub-legal level, the specific regulation of the matter appears in article 655-I of the Normative Resolution. ANEEL No. 1.000/2021[2], a device incorporated into the distributed generation regulation, as follows:
Article 655-I. In billing for group B of a consumer unit participating in the SCEE, the consumer must pay the distributor the sum of the following amounts:
I – portion relating to active energy consumed from the distribution network; and
II – portion relating to active energy injected into the distribution network.
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- 1. The portion relating to active energy consumed from the distribution network is the higher value among those obtained from:
I – availability cost as set forth in article 291; or
II – billing related to energy consumed from the grid, composed of the sum:
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- a) the positive difference between the amount of active energy consumed from the grid and the compensated energy, billed according to the rules applied to other consumers; and
- b) the billing of compensated energy, which must consider the TUSD and TE tariffs applicable to the SCEE of the corresponding subgroup and tariff modality, as well as any applicable tariff discount percentages, according to its classification as GD I, II or III.
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- 2. The compensated energy referred to in paragraph 1:
I – it must be considered up to the limit where the monetary value related to the revenue referred to in § 1 is greater than or equal to the availability cost; and
II – It is limited to the total amount of active electrical energy consumed by the consumer unit in the billing cycle.
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- 3. The portion relating to active energy injected into the grid should be calculated using the following equation:
Billing Usage Injection = (Injection − Consumption) × TUSDg
on what:
Injection is the measured injection demand, in kW;
Consumption is the measured demand required by the system, in kW, limited to the Injection value; It is
TUSDg is the Distribution System Usage Tariff applicable to the generating plant.
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- 4. In the calculation referred to in § 3, the following provisions must be observed:
I – it can only be carried out in consumer units where the metering system is capable of determining the required and injection demands; and
II – It must be initiated after prior notice to the consumer unit, with at least two billing cycles' notice.
Thus, article 655-I establishes that, in the billing of Group B participating in the SCEE (Brazilian Electricity Regulatory System), the consumer must pay two installments: the first referring to the active energy consumed from the grid; the second, when applicable, referring to the active energy injected into the grid.
Paragraph 3 of article 655-I presents the formula for charging for injection usage: Injection Usage Billing = (Injection – Consumption) × TUSDg.
Here arises a crucial technical distinction for the proper legal interpretation of the subject.
Although, in practical terms, people often talk about "injection exceeding consumption," the regulation does not address stored energy in kilowatt-hours (kWh), but rather measured injection demand and required system demand, both in kilowatts (kW).
In other words, the logic behind the billing is not simply a comparison between the total monthly energy generated and the total monthly energy consumed, but rather the determination of an instantaneous power difference between what the unit injects and what it simultaneously demands from the grid, observing the measurement criteria stipulated by... ANEEL.
Below we attempt to illustrate the situation:
EXAMPLES OF CONSUMPTION AND INJECTION:
Residence with a shower with a power of 5,5 kW, used for 02 hours a day.
Power (kW) x Time (h) = Consumption
5,5 kW x 2 h = 11 kWh
PV system with a power of 10kW injecting energy for 02 hours a day.
Power (kW) x Time (h) = Injection
10 kW x 2 h = 20 kWh
EXAMPLES OF WHEN TUSDg IS PAID OR NOT:
1 – If I injected 20 kWh and consumed 11 kWh, I will pay TUSDg on the 9 kWh.
2 – If I injected 20 kWh and consumed 25 kWh, I will not pay TUSDg.
Therefore, TUSDg is only charged if the generation demand is greater than the consumption demand. The incidence of TUSDg depends on the actual electrical behavior of the consumer unit, especially the relationship between the power instantly injected and the power simultaneously consumed from the grid, according to the applicable regulations.
Thus, the greater the actual simultaneity between generation and local consumption, the lower the exposure to charges tends to be, provided that this condition results from the legitimate load profile of the unit, and not from artifices intended to manipulate measurement or billing.
Conditions for charging the TUSDg fee.
From a regulatory standpoint, therefore, the charge is legally permissible in theory, provided that the conditions expressly stipulated in the regulation are observed.
And these conditions are not peripheral; they are structural requirements for the very validity of the charge.
Section 4 of Article 655-I establishes, cumulatively:
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- Prior notice to the consumer with at least two billing cycles' notice; and
- The consumer unit must have a metering system capable of determining the required and injection demands.
Therefore, it is not enough for the distributor to generically invoke the existence of surplus generation. It is essential to demonstrate that it has a metering system capable of technically measuring the quantities required by the regulations and that it observed the proper prior informational procedure. Without these prerequisites, the charge tends to become questionable from a regulatory standpoint.
This aspect is especially relevant because, in practice, many low-voltage consumers have historically been billed based on measurements focused on determining energy consumed and injected, and not necessarily with instruments suitable for measuring instantaneous demand in a manner compatible with the regulatory formula.
This leads to an important development: the abstract legality of the TUSDg in Group B does not, in itself, authorize the conclusion that every concrete charge is valid. Between the normative authorization and the effective enforceability there is a technical-probative space that needs to be filled by the distributor or concessionaire.
In the event of a controversy, the discussion tends to shift precisely to the adequacy of the measurement system, the clarity of the advance notice, and the adherence of the billing to the regulatory model.
Differences between the TUSDg applicable to Group A and the TUSDg applicable to Group B.
Another point that deserves reflection is the difference between the TUSDg applicable to Group B and the TUSDg of Group A, which are distinct regulatory realities.
In Group A, the discussion revolves around units with billing based on contracted demand and traditionally more sophisticated metering; in Group B, on the contrary, billing based on injection usage was conceived as a specific and conditional hypothesis, aimed at scenarios in which the unit, even at low voltage, uses the network as a way to discharge excess power at a level higher than the power simultaneously required from the system.
Confusing these two systems leads to frequent errors in the market, either exaggerating the effects of the rule or denying, without legal basis, the very existence of the charge.
The issue becomes even more delicate when examining the situation of power plants classified as GD I, that is, those protected by the transitional regime and frequently associated with so-called acquired rights. There is a regulatory interpretation suggesting that the TUSDg charge for Group B would also apply to these plants, although this point remains legally sensitive and subject to controversy.
Legally, this is the most sensitive area of the debate. This is because the acquired right under Law No. 14.300/2022 was built, above all, around the preservation of the billing and compensation rules applicable to consumers already included in the SCEE under the previous regime.
The extent to which this protective regime can be extended to prevent or not a charge based on the use of fuel injection is a question that cannot be resolved with a purely literal reading, requiring a systematic analysis between the law, the regulation, and the constitutional limits of protection for legally perfected acts and acquired rights. The issue, therefore, seems less settled than part of the market assumes. The very text itself points to this potential for litigation.
Artificial load to circumvent TUSDg: operational fraud and legal risks in distributed generation.
The discussion regarding the TUSDg (Transmission System Usage Tariff) in distributed generation cannot be addressed solely from an economic perspective. It also requires a rigorous legal analysis of the boundaries between legitimate energy planning and the improper manipulation of the metering and billing system.
It is precisely at this point that concern arises regarding the use of artificial load, a practice that has been associated with attempts to improperly avoid or reduce the incidence of the Distribution System Usage Tariff applicable to generation.
In practical terms, so-called artificial load consists of the programmed use of equipment, controls, or technical devices intended not to meet a real consumption need of the consumer unit, but to produce a strategic behavior of the metering system.
In other words, an appearance of instantaneous consumption is created with the purpose of interfering with the technical record of the unit's operation, influencing billing and artificially reducing the difference between injected power and consumed power. When this occurs, one leaves the field of efficient energy management and enters the realm of operational manipulation for improper economic purposes.
The seriousness of the conduct stems precisely from its purpose. The legal system allows for planning, proper load sizing, synchronization between consumption and generation, and the adoption of legitimate energy efficiency strategies.
What is unacceptable is the intentional use of artificial mechanisms aimed solely at altering the measurement result in order to circumvent the tariff logic defined by legislation and sector regulation.
The distinction is important: it's one thing to technically organize the unit's operation for better energy efficiency; it's quite another to simulate consumption or induce fictitious meter behavior to evade a regulatory obligation.
From a legal perspective, this practice breaks with the very rationality of the Distributed Generation Legal Framework. Law No. 14.300/2022 was designed to ensure legal certainty, regulatory predictability, and the sustainable expansion of distributed generation. It is a regime aimed at protecting regular, transparent activity that adheres to technical and tariff standards.
In this model, there is no room for interpretation that the legal system would protect methods intended to simulate electrical quantities or manipulate the assessment of network usage.
Therefore, when proven, artificial tax burden cannot be treated as a mere billing dispute: it is closer to the notion of operational fraud, as it consists of intentional behavior aimed at obtaining undue advantage to the detriment of the sector's regulatory logic.
The problem is exacerbated because attempts to circumvent the TUSDg (Transmission and Distribution System Usage Tariff) affect not only the individual relationship between consumers and distributors or cooperatives. The electricity grid is a shared infrastructure, and the tariff system seeks to distribute its costs in a minimally balanced way among users.
When an agent adopts artificial mechanisms to unduly reduce the amount that would be charged to them, they distort the economic signaling of the system and shift costs to the other participants.
Therefore, the issue goes beyond the individual contractual sphere and takes on broader regulatory relevance, as it affects the integrity of the compensation model and the very balance of the public distribution service.
It is also important to note that fraud, in this context, is not presumed. Alleging wrongdoing requires a solid evidentiary basis, sound technical demonstration, and adherence to due regulatory procedure. This care is crucial because increased oversight in the sector can, in some cases, lead to hasty conclusions, poorly substantiated accusations, or fines based on weak presumptions.
The discipline of REN itself ANEEL Decree No. 1.000/2021 mandates due process, guarantees of adversarial proceedings, full defense rights, and adequate production of expert evidence. Thus, although the use of artificial cargo may indeed constitute serious fraud when proven, its investigation requires formality, justification, and observance of the minimum guarantees for the consumer and other parties involved.
From the perspective of consequences, the legal risks are significant. In the administrative and regulatory sphere, the finding of manipulation may lead to a review of billing, retroactive rebilling, disregard of energy records, intensified inspections, and the adoption of punitive measures by the distributor, concessionaire, or cooperative, within the applicable regulatory limits.
In the civil sphere, discussions may arise regarding compensation for losses, liability for damages, and reimbursement of losses eventually suffered by the concessionaire or third parties. In the criminal sphere, although the classification always depends on concrete analysis, robust evidence, and specific elements of the crime, the conduct may give rise to allegations of obtaining undue advantage through fraud, which demonstrates the seriousness of the issue.
According to the institutional publication of Cermissões [3] (licensee in Rio Grande do Sul), units were identified that, over a period of approximately 30 days, had carried out artificial load injection for about 30 minutes, just to generate a punctual consumption record — which would not correspond to the actual consumption of the consumer unit. The stated objective would be to improperly reduce or eliminate the TUSDg charge.
Cermissões also reports that it has formally questioned... ANEEL, and that the Agency, through Official Letter No. 219/2025-STD [4], would have recognized unusual behavior in the records and indicated that cargo simulation may constitute fraud against the law, that is, the ANEEL It was understood that records with isolated consumption peaks in a short period of time may indicate behavior incompatible with the normal operational routine of the consumer unit, and that the use of simulated loads to obtain undue advantage may constitute fraud against the law, citing article 187 of the Civil Code.
There is also a business aspect that deserves attention. In many cases, the suspicion of artificial load does not only fall on the owner of the consumer unit, but can also have effects on integrators, technical managers, monitoring companies, operational managers, and corporate structures linked to the project.
Without well-drafted contracts, a clear definition of responsibilities, and robust technical and operational governance, the investigation of an irregularity tends to produce a chain reaction of conflict, in which each party seeks to deflect responsibility and place it on the other. In an increasingly professionalized market, this reveals the need for technical compliance, operational traceability, adequate documentation, and preventive legal advice.
In short, artificial load represents one of the most sensitive aspects of the new regulatory phase for distributed generation. As oversight of grid use and the correct application of the TUSDg (Transmission System Usage Tariff) increases, the sector is demanding not only economic efficiency but also operational integrity and legal compliance.
Regular distributed generation remains protected by regulations and encouraged by legislation. What is not covered by regulations is the intentional manipulation of the metering system to obtain undue advantage. Therefore, more than a simple "strategy to reduce costs," artificial load, when configured, should be understood as potentially fraudulent conduct, capable of triggering administrative, civil, and, in extreme situations, even criminal consequences.
The legality of the charge and the actual validity of the invoice.
From a dogmatic standpoint, the defense of the legality of the charge stems from a simple premise: if the consumer unit uses the grid not only to consume energy but also to inject surplus power, there is an autonomous use of the infrastructure that can justify specific remuneration, provided that this remuneration has a legal basis and strict regulatory compliance.
The main line of contention tends to focus on three fronts:
- (i) absence or insufficiency of the measuring apparatus required by ANEEL;
- (ii) failure to observe the minimum notice period of two billing cycles; and
- (iii) potential violation of the legal regime of units with acquired rights, insofar as the charge imposes on them a supervening burden incompatible with the protection ensured by Law No. 14.300/2022 and the Constitution.
There is also a practical dimension that cannot be ignored. The TUSDg (Transmission System Usage Tariff) for Group B does not simply result from the fact that the plant "generates a lot" in the month, but from the occurrence of power injection exceeding simultaneous consumption.
This finding has a direct impact on the technical planning of systems, the sizing of the plant, the load profile of the unit, and the way integrators and consultants should advise their clients.
In other words, the legal discussion is inseparable from the engineering of consumption. Poorly designed projects, with low simultaneity between generation and local load, tend to increase exposure to charges; on the other hand, systems designed to adhere to the instantaneous consumption profile can mitigate this risk, without the need for artificial expedients or legally weak solutions.
The TUSDg charge can be questioned when there is:
- Lack of a measurement system capable of measuring the required quantities;
- Failure to give prior notice of two billing cycles;
- Error in the calculation or in the methodology applied;
- Impact on units with vested rights, potentially violating the transitional legal regime and legal certainty.
The debate, therefore, must be approached with technical seriousness and not with commercial simplifications.
To date, no consolidated and specific judicial case law has been identified regarding the collection of the TUSDg fee under Article 655-I of REN No. 1.000/2021 for Group B units, especially concerning power plants with acquired rights.
This does not mean that the issue cannot be litigated. On the contrary: it is a matter with evident potential for contention, especially in cases where the charge falls on units classified as GDI or is implemented without strict adherence to technical and procedural requirements. We even have several ongoing cases in our office discussing this matter, and I hope to have news soon.
Therefore, the discussion regarding TUSDg in Group B is not limited to the existence of abstract regulatory authorization. The concrete enforceability of the charge depends on technical support, strict adherence to the regulatory model, and observance of the consumer's procedural guarantees.
In tariff matters, especially when there is a significant economic impact, the legality of the charge and the regularity of the procedure go hand in hand.
Therefore, the topic still appears to be in a phase of legal and regulatory maturation.
Conclusion
In conclusion, the most accurate legal answer to the question posed in the title is as follows: the collection of TUSDg on Group B units is, in theory, lawful, because it is based on Article 18 of Law No. 14.300/2022 and specific regulation in Article 655-I of the REN. ANEEL No. 1.000/2021.
However, its actual validity depends on the rigorous fulfillment of the technical and procedural requirements established by the regulation itself, especially proper measurement and prior notification.
Furthermore, a significant area of controversy persists regarding the application of this charge to units with acquired rights, a topic that may still be further developed in the judicial and legislative spheres. Therefore, in matters of distributed generation, it is not enough to ask whether the charge exists; it is necessary to ask when, how, and against whom it can be legitimately demanded.
At this point, it is important to be intellectually and legally honest: I cannot confirm, to date, consolidated and specific judicial case law on the collection of TUSDg under art. 655-I for Group B units [5], especially under the perspective of acquired rights.
Yes, there is regulatory and legislative debate regarding charges levied on distributed generation, including subsequent legislative proposals aimed at reducing charges for grid use, which demonstrates that the issue remains politically and legally alive.
The discussion about TUSDg in Group B reveals how distributed generation has entered a phase of greater legal and regulatory sophistication. The time for simplistic answers is over. For consumers, integrators, investors, and legal professionals, the challenge now is to interpret the regulation with technical precision, without losing sight of the constitutional and regulatory limits that condition the charge.
References
[1] BRAZIL. Law No. 14.300, of January 6, 2022. Establishes the legal framework for distributed microgeneration and minigeneration, the Electric Energy Compensation System (SCEE) and the Social Renewable Energy Program (PERS); amends Laws No. 10.848, of March 15, 2004, and No. 9.427, of December 26, 1996; and provides other measures. Official Gazette of the Union: section 1, Brasília, DF, January 7, 2022. Available at: https://www.planalto.gov.br/ccivil_03/_ato2019-2022/2022/lei/l14300.htm. Accessed on: 19 abr. 2026.
[2] NATIONAL ELECTRIC ENERGY AGENCY (ANEELRegulatory Resolution No. 1.000, of December 7, 2021. Establishes the Rules for the Provision of the Public Electricity Distribution Service; revokes the Regulatory Resolutions. ANEEL Decree No. 414, of September 9, 2010, Decree No. 470, of December 13, 2011, Decree No. 901, of December 8, 2020, and other provisions. Official Gazette of the Union: Section 1, Brasília, DF, December 14, 2021. Available at: https://www.in.gov.br/en/web/dou/-/resolucao-normativa-aneel-n-1.000-de-7-de-dezembro-de-2021-368359651. Accessed on: 19 abr. 2026.
[3] CERMISSÕES. Cermissões inspection uncovers fraud in solar panel systems. Cermissões, [2025]. Available at: https://www.cermissoes.com.br/fiscalizacao-da-cermissoes-flagra-fraude-em-sistemas-de-placas-solares/. Accessed on: 19 abr. 2026.
[4] CERMISSÕES. Cermissões inspection uncovers fraud in solar panel systems. Cermissões, [2025]. Available at: https://www.cermissoes.com.br/fiscalizacao-da-cermissoes-flagra-fraude-em-sistemas-de-placas-solares/. Accessed on: 19 abr. 2026.
[5] OLIVEIRA, Juliana de. TUSD G being charged to UFV group B (low voltage): is the charge lawful? Oliveira e Rohr Advocacia, July 2, 2025. Available at: https://oliveiraerohr.com.br/blog/tusd-g-sendo-cobrada-de-ufv-do-grupo-b-baixa-tensao-e-licita-a-cobranca/. Accessed on: 19 abr. 2026.
The opinions and information expressed are the sole responsibility of the author and do not necessarily represent the official position of the author. Canal Solar.
An answer
The collusion between ANEEL and operators, acting in a way that creates artificial benefits for the latter, to the detriment of the citizen who decided to generate their own energy.
Given the harm they have done to the country as a whole and to citizens in particular, these agencies should be abolished. By doing so, the government would eliminate a major source of corruption and an instrument that, since its creation, has been used to benefit, in this case, the operators, to the detriment of society as a whole.