$3.2 Billion Agreement Could Change Operation of 1.2 GW at Eneva’s Power Plants and Lower Brazilian Electricity Costs
$3.2 Billion Agreement Could Change Operation of 1.2 GW at Eneva’s Power Plants and Lower Brazilian Electricity Costs
According to Reuters, a report published on Monday, September 21, 2026, an agreement led by Brazil’s Federal Court of Accounts could change the operation of Eneva’s thermal power plants, which total approximately 1.2 GW, within the Brazilian electricity system.
Rather than maintaining a portion of generation functioning continuously even when there is an oversupply of electricity, the proposal would allow the plants to be activated as needed by the system. Studies presented during the proceedings estimate savings of R$ 1.7 billion to R$ 3.2 billion for regulated market consumers between 2026 and 2030.
The Agreement Seeks to Shut Down Thermal Plants When They’re Not Needed
Currently, the contracts under discussion have inflexible rules. Simply put, this means a certain portion of energy must be continuously produced, even during times when the system already has sufficient electricity.
The proposed approach takes this logic in a different direction. Thermal plants would be activated by the National Electric System Operator (ONS) when generation is needed or when it makes economic sense to put them into operation.
These are contracts signed at different times, when the composition of Brazil’s electricity matrix was also different. Since then, the amount of solar and wind farms has increased and made it more common for periods of high renewable generation to occur simultaneously.
Four Power Plants Are Part of Three Contracts Under Discussion
The process involves the Maranhão III thermoelectric plant, known as Parnaíba II, the MC2 Nova Venécia 2 thermoelectric plant, linked to the Parnaíba complex, and the Azulão II and Azulão IV plants, which are treated together in one of the projects.
These units are located in Maranhão and Amazonas and utilize natural gas. Together, they represent more than 1.2 GW of capacity that could see a change in their operating rules.
The Maranhão III plant has approximately 519 MW of installed capacity. The combined capacity of Azulão II and IV is 590 MW, while the structure of MC2 Nova Venécia 2 is also participating in the agreement through the reviewed contracts.
One Estimate Points to R$ 1.7 Billion, Another Reaches R$ 3.2 Billion
The higher figure from the negotiation did not arise from a single estimate.
According to documents cited by Reuters, the Electric Energy Trading Chamber (CCEE) estimated savings of approximately R$ 1.7 billion. An analysis by consultancy PSR arrived at R$ 3.2 billion for the considered period.
The calculations were presented in a proposal by Eneva to the federal government and appear in documentation sent by the Ministry of Mines and Energy to the National Electric Energy Agency.
This is still a projection. The consumer has not received this money, and there is no guaranteed reduction of R$ 3.2 billion (about US$600 million) on their electricity bill.
The problem arises when there is excess energy in the system
The logic seems strange at first glance. If Brazil has an abundance of electricity, why shut down solar or wind power plants that can produce without burning natural gas?
Part of the answer lies in the contracts.
Thermal plants classified as inflexible need to maintain certain levels of production. When this energy coincides with periods of high solar or wind generation, the system can become overloaded with more electricity than it can consume or transport at that moment.
At that point, the National Electric System Operator (ONS) needs to reduce output from other plants.
The sector refers to this cut as curtailment. In simple terms, it means instructing a plant to decrease or halt part of its production because the system cannot utilize all that electricity at that moment.
Wind and solar energy may be wasted while thermal plants remain online
This phenomenon has become more pronounced with the rapid growth of renewable sources.
A wind turbine may be spinning and a solar park may be ready to produce, but the electricity might not reach consumers if there is already enough generation or limitations within the grid.
In the case analyzed by Brazil’s Federal Court of Accounts (TCU), the contractual inflexibility of thermal plants is precisely what impacts this equation. Since these units have minimum generation obligations, part of the renewable energy may end up being curtailed to accommodate them within the National Interconnected System.
The proposal seeks to create space to do the opposite when conditions allow: reduce thermal production and utilize more electricity from other sources.
The ONS estimates a potential reduction of 215 average MW in cuts
There is a concrete measure of the operational effect being discussed.
According to the proposal reported by Reuters, analysis from the ONS indicated that the flexibility could reduce generation cuts by up to 215 average megawatts.
Average megawatt is a way of representing the average amount of energy generated over a specific period. It does not simply mean that 215 MW of new plants would emerge in the country.
In practice, this number reflects how much energy that is currently limited by the system would have the potential to continue being produced if the operation of thermal plants became more flexible.
The variable cost of the plants would stand at R$ 760 per MWh
The agreement does not simply mean shutting down thermal plants.
The idea is to change when they come into operation. The National Electric System Operator (ONS) could dispatch them based on security needs or economic merit, using an operational variable unit cost of R$ 760 per megawatt-hour outlined in the proposal.
This would allow for thermal capacity to be preserved for times when it is truly needed.
For instance, when the wind decreases, solar generation drops, or demand suddenly spikes, these machines could resume production as determined by the operator.
It is precisely this ability to respond to system changes that has made flexibility an increasingly valuable component in the electrical grid.
Thermal Plants Remain Important When Solar and Wind Drop
The debate does not position renewable energy and thermal power as technologies that simply replace one another.
Solar and wind depend on natural conditions. A cloud can rapidly diminish photovoltaic production in an area, while changes in wind patterns affect the performance of wind farms.
Thermal power can kick in when this production falls or when consumption rises.
Eneva itself recorded 2,230 GWh of thermal power generation in the second quarter of 2026, a 46% increase compared to the previous year. According to the company, the rise occurred during a period when the system required more of this type of generation to supplement other sources.
What is under discussion at the Federal Court of Accounts (TCU) is how much of this production needs to remain mandatory at all times.
Eneva Would Assume Part of the Risk of Change
There is a delicate point in the negotiation: altering old contracts can create new costs.
The proposal works with a condition called tariff neutrality. The intention is to prevent distributors from paying more due to the change in rules.
If additional costs arise in the short-term electricity market, the proposal stipulates that they will be borne by Eneva itself, according to documents cited by Reuters.
At the same time, information obtained by Agência iNFRA indicates that one of the alternatives being discussed preserves established revenues in contracts and allows for greater flexibility in the energy delivered. Part of this energy could even come from renewable sources either produced in-house or acquired from third parties.
This framework still needs to navigate the regulatory stage.
Aneel Emerges as a Key Player Before Final Agreement
On the morning of this Monday, Agência iNFRA reported that the Ministry of Mines and Energy and Eneva had already made progress on the terms of one of the proposals, while the approval of Aneel remained necessary to finalize the negotiation.
The process is being conducted within the SecexConsenso, a TCU structure used to seek negotiated solutions in controversies involving public administration, regulation, and companies.
The committee was formed following a request from the Ministry of Mines and Energy. The TCU formalized the group in May 2026 to specifically address the disputes in the contracts of these power plants.
It is not an automatic change. The framework needs to respect existing contracts, regulatory rules, and the safety of electrical operations.
Change Could Start in July 2027
If the agreement is approved as presented, the new mode of operation would commence in July 2027.
The choice of the period is not arbitrary. According to the document cited by Reuters, July coincides with the highest level of inflexibility of the involved thermal plants and with the so-called “wind harvest,” a time when wind production typically strengthens in key areas for the Brazilian system.
It is precisely when the risk of generation competing for the same grid space may increase.
With flexible thermal plants, the operator would have greater freedom to decide which source to use at any given moment.
An old contract now faces a different energy matrix
The Maranhão III thermoelectric plant is linked to a contract originating from the A-3 Auction in 2011. Other projects discussed were contracted in subsequent auctions, including the expansion of the MC2 Nova Venécia 2 thermoelectric plant and the Azulão II and Azulão IV plants.
Between those auctions and 2026, the Brazilian energy matrix has changed.
Only until August of this year, the National Electric Energy Agency (Aneel) registered 4,852.78 MW of new installed capacity coming online in the country. Of this total, 3,520.93 MW came from solar photovoltaic plants.
The amount of energy produced at certain times has increased faster than the capacity to utilize it fully.
Contracts designed for a different scenario now coexist with a grid where flexibility is as valuable as installed capacity.
The decision could set a precedent for other thermoelectric plants
The implications of the process could extend beyond Eneva’s units.
In July, João Daniel Cascalho, the secretary of Electric Energy at the Ministry of Mines and Energy, stated during an event by the Federal Court of Accounts (TCU) that the government viewed the negotiation as a potential reference for other contracts with high inflexibility.
This places greater weight on the current decision.
If the model works legally and produces the expected operational gains, similar contracts may find their way back to the table in the future.
For now, the figures remain estimates: R$ 1.7 billion (about US$320 million) in the CCEE account and R$ 3.2 billion (about US$610 million) in PSR’s analysis.
The next step is regulatory. If there is an agreement, the change will begin to materialize in July 2027, when 1.2 GW of thermal capacity may stop producing due to continuous obligation and instead be on standby for when the system actually needs them.