The Aneel decision to block contractual changes at Eneva power plants frustrates expectations of lower electricity bills for residential consumers and leaves the sector at an impasse.
The National Electric Energy Agency (Aneel) rejected a request on Monday (Sept. 21, 2026) from the company Eneva that sought to modify contractual terms for three of its thermoelectric units. According to market analysts, the veto prevented a move that could have lowered energy costs for consumers in the so-called captive (residential) market.
The proposal sought to end the mandatory continuous operation requirement for the Maranhão III, MC2 Nova Venécia 2, and Azulão II power plants. Under the new plan, these facilities would have had their Unit Variable Cost set at R$ 760 per megawatt-hour and would have shifted to operating only in critical situations, serving as a safety net for the stability of the national electric system.
Although the flexibility could have resulted in annual savings of R$ 223 million on residential electricity bills, the Aneel board chose to uphold the original contracts. The agency’s primary concern lies in the immediate impact of the adjustment: the proposal would have created a short-term financial exposure of approximately R$ 4.9 billion, a burden that would have been passed on to industries and major consumers in the free energy market.
The dilemma of flexibility in the power sector
The debate surrounding non-flexible power plants reflects the evolution of Brazil’s energy matrix, which now relies heavily on renewable sources like wind and solar. Unlike traditional thermal plants that operate continuously, experts argue that the National Electric System Operator (ONS) needs agile plants capable of turning on and off quickly to compensate for natural fluctuations.
“The major problem today is the lack of power plants with operational flexibility—that is, plants that the ONS can operate to address significant variability,” noted Claudio Sales, president of the Instituto Acende Brasil. According to the executive, the current model forces consumers to pay for energy that is often not needed full-time, hindering investments in efficiency.
On the other hand, the Aneel board maintained a cautious stance. Without an internal consensus—the measure was rejected by a 3-2 vote—the directors concluded there were insufficient guarantees of economic security to sustain the change for the next 24 years. The simulations presented covered only the next five years, creating uncertainty regarding the sector’s long-term financial balance.
Faced with this impasse, the future of these operations remains uncertain while the administrative process continues to be monitored by the Federal Court of Accounts (TCU). In the meantime, Eneva is still evaluating its next steps, and the power sector continues to debate how to balance residential tariffs with the financial risks faced by major market players.
