The grid was producing more electricity than it could safely handle.
No Brasil, a promessa da energia solar distribuída está sendo corroída por dentro: consumidores que já desfrutam de generosos subsídios governamentais expandem clandestinamente suas instalações para capturar ainda mais benefícios, enquanto os custos recaem sobre os que menos têm. O fenômeno do 'gato solar' não é apenas uma fraude contábil — é um sintoma de um sistema que, ao recompensar quem já venceu, pune quem nunca teve a chance de jogar. A estabilidade da rede elétrica e a justiça tarifária dependem, agora, da vontade política de reformar o que a conveniência construiu.
- Consumidores já subsidiados pelo programa GD1 instalam painéis extras ilegalmente para multiplicar os créditos que recebem, transferindo o custo a milhões de brasileiros de baixa renda que pagam a conta sem ter sol no telhado.
- A geração clandestina invisível distorceu os cálculos do ONS a ponto de, em junho, o operador nacional ordenar o primeiro corte emergencial de geração solar distribuída — não por falta de sol, mas por excesso de energia sem controle.
- Nas redes de distribuição, a corrente invertida por painéis não declarados eleva a tensão além dos limites seguros, danificando eletrodomésticos de vizinhos e colocando em risco eletricistas que trabalham em circuitos que deveriam estar desenergizados.
- Concessionárias formaram forças-tarefa para rastrear instalações ilegais, mas a fiscalização reativa não resolve o problema estrutural: o sistema atual torna a fraude quase racional para quem já está dentro.
- A saída apontada por especialistas — medição em tempo real obrigatória e créditos calculados pela tarifa horária, como fazem Alemanha e Austrália — existe, mas exige que o Congresso escolha o consumidor comum em vez dos lobbies que lucram com o status quo.
O sistema brasileiro de geração solar distribuída está sendo esvaziado por dentro por um esquema simples: quem já recebe subsídios generosos do programa GD1 — garantidos até 2045 — instala painéis adicionais sem autorização para capturar ainda mais energia subsidiada e vender o excedente à rede em condições vantajosas. O custo não desaparece; ele é absorvido por todos os demais consumidores, especialmente os de menor renda, que financiam os benefícios de quem já pode pagar por painéis solares. A Aneel confirmou que isso está acontecendo em escala.
As consequências vão além das finanças. A geração clandestina torna o sistema elétrico opaco: o ONS não consegue prever a demanda real quando há produção invisível distorcendo todos os cálculos. Em junho, pela primeira vez, o operador precisou ordenar um corte parcial da geração solar distribuída — não por escassez, mas porque havia eletricidade demais fluindo sem controle. Excesso de energia pode causar apagões tão facilmente quanto a falta dela.
Nas redes locais, o perigo é físico. As linhas de distribuição foram projetadas para conduzir corrente em um único sentido — das subestações para as casas. Painéis ilegais invertem esse fluxo sem que a concessionária saiba, elevando a tensão a níveis que danificam aparelhos de vizinhos e, pior, eletrocutam trabalhadores que entram em circuitos que deveriam estar mortos.
A solução técnica existe: medição em tempo real obrigatória em cada instalação solar, combinada com créditos calculados pela tarifa horária de mercado, modelo já adotado por Alemanha, Austrália e partes dos Estados Unidos. Mas a solução real é política. Enquanto o Congresso não priorizar o consumidor comum sobre os lobbies que se beneficiam do sistema atual, a rede continuará se desestabilizando — e os mais pobres continuarão pagando a conta dos painéis de quem já pode pagar por eles.
Brazil's distributed solar energy system is being quietly hollowed out by a scheme so straightforward it's almost elegant: people who already benefit from generous government subsidies install additional solar panels without permission, pocket the extra subsidized power, and leave everyone else to cover the bill. The practice, known colloquially as "gato solar"—solar theft—has become common enough that power companies have launched coordinated task forces to hunt it down. But the real problem isn't the individual installations. It's that the system makes this kind of fraud almost rational.
The mechanics are simple. Brazil's distributed generation framework, particularly a category called GD1, locks in full subsidies for participating households through 2045. For someone already enrolled, the math is tempting: install more panels, generate more subsidized electricity, and sell the surplus back to the grid at favorable rates. The cost of those subsidies doesn't vanish—it gets absorbed by everyone else, disproportionately lower-income households without solar systems of their own. According to Brazil's electricity regulator, the Aneel, this is exactly what's happening. Consumers who've already won the subsidy lottery are expanding their systems illegally to win it again and again.
The grid consequences are more serious than accounting fraud. When clandestine solar installations pump power back into the network without the utility company knowing about it, the electrical system loses its ability to predict and balance demand. Brazil's national grid operator, the ONS, found itself unable to forecast how much power the system actually needed because invisible generation was distorting every calculation. In early June, for the first time, the ONS ordered a partial shutdown of distributed solar generation—not because the sun wasn't shining, but because the grid was producing more electricity than it could safely handle. Too much power flowing in the wrong direction can cause blackouts as easily as too little.
At the distribution level, where power flows to individual neighborhoods, the danger becomes physical. Electrical grids are engineered with current flowing one direction: from the utility's substations outward to homes and businesses. Illegal solar panels reverse that flow without the utility's knowledge, pushing power backward through lines designed for one-way traffic. Voltage can spike beyond safe operating limits, damaging appliances in neighboring homes whose owners never chose to participate in this system. Worse, utility workers entering a circuit they believe is de-energized can be electrocuted by power flowing backward from an invisible source.
The solution is bureaucratic but essential: mandatory real-time metering on every distributed solar installation. If every system had a device continuously recording how much power it's injecting into and drawing from the grid, utilities would see exactly what's happening. Fraud would become visible. The grid operator could plan accurately. Safety risks would evaporate. Several countries have already moved in this direction—Germany, Australia, and parts of the United States have shifted from measuring solar credits in kilowatt-hours to pricing them based on the actual hourly market rate for electricity. Brazil could do the same, but only if it first knows what's actually being generated.
The deeper issue, though, isn't technical. It's political. The current system creates perverse incentives: it rewards people for gaming it and punishes those without the resources or knowledge to participate. Fixing it requires the Brazilian Congress to prioritize ordinary consumers over the lobbies that benefit from the status quo. Until metering becomes mandatory and enforcement becomes real, the grid will keep destabilizing, workers will keep facing hidden hazards, and the poorest households will keep subsidizing the solar panels of people who can already afford them.
Citas Notables
The business model is to install new solar panels to capture more subsidized energy, which is mostly paid for by consumers without solar, typically with lower incomes.— Aneel technical analysis (Note 148/2025-STD)
The problem in the electrical sector is fundamentally political, not technical.— Jerson Kelman, Folha de S.Paulo
La Conversación del Hearth Otra perspectiva de la historia
So these illegal solar installations—are we talking about a few people cutting corners, or is this widespread?
It's widespread enough that power companies have mobilized task forces specifically to hunt them down. The Aneel's technical analysis makes clear this isn't marginal. People who already have subsidized solar are systematically adding more panels without permission to capture additional subsidized energy.
But why would someone do that if they're already getting subsidies?
Because the subsidy is locked in through 2045. Once you're in the GD1 category, you keep those benefits no matter what. So the incentive is to expand as much as possible—more panels, more generation, more subsidized power flowing back to the grid at favorable rates.
And who pays for that extra subsidy?
Everyone else, but especially lower-income households without solar. Their electricity bills fund the subsidies for people who are already better off and gaming the system further.
The grid operator had to shut down solar generation in June. That seems extreme.
It is. The system couldn't predict demand because so much generation was invisible—happening without the utility's knowledge. Too much power flowing in the wrong direction can cause blackouts as easily as too little. The grid operator was flying blind.
What's the actual danger if power flows backward through lines designed for one direction?
Voltage spikes that damage appliances in neighboring homes. Workers entering circuits they think are safe but aren't. The grid becomes unpredictable and unsafe. It's not just an accounting problem.
So the fix is metering?
Mandatory real-time metering on every system. If utilities could see exactly what every installation is generating and consuming, fraud becomes visible, the grid operator can plan accurately, and safety risks disappear. Germany and Australia have already done this. Brazil can too—but only if it has the political will.