Brazil's power transmission and distribution infrastructure and its operation by grid operator ONS — including renewable-absorption limits and curtailment mechanisms.
Last 90 days
ONS triggered the Surplus Management Plan on August 23 for the second time this year, restricting smaller plants on distribution grids from 11:00 to 13:30 — days after announcing Erag, an automatic solar-curtailment scheme with up-to-3 GW design capacity and a pilot expected by end-2026. Surplus generation on low-demand days has become a structural operating problem.
Updated November 10, 2026 · 16 verified articles
Market transmission
Grid constraints define how much renewable generation becomes revenue: curtailment rules, compensation and transmission/storage investment shift returns among generators, transmission firms and consumers.
Explanatory mechanism, not a forecast or recommendation.Aneel proposed the Hora Certa tariff, with time-of-use energy pricing for low-voltage consumers, which could reach about 5.7 million units from 2028, according to Agência Brasil and Times Brasil.
The Paraguayan side of Itaipu held about US$ 182 million at Ueno Bank until November 3, while the Brazilian side had no funds there, according to a note from the binational cited by InfoMoney and CNN Brasil.
Aneel announced on October 30 that November tariff flag will be green, with no extra charge on power bills, according to Agência Brasil and CNN Brasil.
The Aneel transmission auction held at B3 on October 30 had five winners and eight lots awarded, with about R$ 8.9 billion in planned investment, according to B3 and NeoFeed.
Brazil's Supreme Court ruled, on motions for clarification, that the ten-year window for power distributors to refund consumers PIS and Cofins overcharged on ICMS in power bills starts when they recover the amount from the Federal Revenue Service or when the tax offset is definitively approved, according to the court and CNN Brasil.
The National Electric Energy Agency set on September 25 the green tariff flag for October power bills, with no extra charge. The yellow flag, which added R$ 1.885 per 100 kWh consumed, had been in place for five months. According to Aneel, increased rainfall, especially in the South and Southeast, stabilized hydroelectric reservoirs and reduced the need to dispatch costlier thermal plants.
The third 2026 edition of Aneel's InfoTarifas bulletin projects an average tariff effect of 9.4% for the year, up from 8.6% in the previous edition and above projected IGP-M (4.4%) and IPCA (5.0%). Financial components account for 4.7 points, sector charges 1.6, energy purchases 1.1, transmission 0.9 and Parcela B 0.8. Distributing about R$ 5.5 billion in UBP funds to utilities in the Sudam and Sudene areas cut the pressure by 1.9 points.
Cemig approved R$ 200 million in interest on equity, R$ 0.06991340114 per share, with a September 22 record date and ex-trading from September 23. Payment comes in two installments, by June 30 and by December 30, 2027, according to Money Times and InfoMoney.
Lula signed on September 15 the Redata, a special tax regime for data center services that suspends four federal taxes on equipment purchases and imports for up to five years, with a revenue loss estimated at R$ 5.2 billion in 2026 and about R$ 1 billion a year afterwards; companies must run on renewable or low-emission energy, reserve at least 10% of processing capacity for the Brazilian market and direct investment to research and to the North, Northeast and Centre-West, or return the benefit. The definition of eligible energy sources was left to a ministerial order, and a senator threatened to react with a legislative decree if natural gas is excluded, per Poder360; the ICMS cut depends on Confaz.
The 3rd Business Court of Rio de Janeiro ruled on September 9 to close Light's judicial reorganisation, declaring all plan obligations verified in the supervision period fulfilled; the company reported the decision to the market and drops the in-reorganisation label from its records. The process, begun in May 2023, restructured about R$ 11 billion, including R$ 7 billion in debentures and R$ 3.1 billion in bonds.
The National Electric System Operator is weighing activating on the September 7 holiday the emergency protocol that orders distributors to curtail generation from large and small plants during low-load periods, per CNN Brasil and Poder360. ONS rates the chance of activation as low on Monday and moderate on Sunday, September 6; the plan was already triggered on June 7 and August 23 this year, per Poder360.
The Finance Ministry authorized on September 4 a US$ 1 billion credit line from the Inter-American Development Bank for Eco Invest Brasil, a program to mobilize private capital for the ecological transition with currency protection, per Agência Brasil and Correio Braziliense. The National Treasury page describes the program as an instrument to promote foreign investment in green projects.
The board of Axia Energia, formerly Eletrobras, approved on September 3 the redemption of 111,591,072 class C preferred shares at R$ 55.56 each, R$ 6.2 billion in total, per InfoMoney and Money Times. The PNC shares were created in 2025 to distribute profit reserves through a stock bonus, and holders may opt to convert into common shares one for one.
The Senate approved on September 1 the Special Tax Regime for Data Centers (Redata), which goes to presidential sanction, per Agência Brasil, Exame and Money Times. Conditions include reserving at least 10% of capacity for the Brazilian market and using renewable energy. Estimated forgone revenue is R$ 5.2 billion in 2026 and about R$ 1 billion a year in 2027 and 2028.
Eneva completed the sale of the shares of Pecém II, a coal-fired plant in Ceará, for R$ 839.2 million in total, per InfoMoney; Money Times details R$ 748.4 million paid at closing and up to R$ 149 million more subject to conditions. Per InfoMoney, the company also signed a deal with Diamante Geração de Energia to swap its coal plant for a stake in a Pecém company. The deal was announced on September 1 and stayed blocked at NEXO until Money Times completed the double confirmation.
Grid operator ONS triggered its Energy Surplus Management Plan on Sunday, August 23, restricting generation from smaller plants connected to distribution grids from 11:00 to 13:30 — the mechanism's second activation in 2026. The episode comes days after the operator announced Erag, an automatic solar-curtailment scheme with up-to-3 GW design capacity and a pilot expected by year-end.