According to the grid operator, new lines will restore wind and solar generation levels seen before the August 2023 blackout
10/22/2024
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Brazil’s national grid operator ONS has increased the capacity to transmit renewable power from Brazil’s Northeast to the rest of the country with the activation of three new transmission lines and a power substation. These assets received operational clearance last week.
According to ONS, the new lines will allow the operator to reduce the restrictions on wind and solar generation to levels observed before a blackout in August 2023. The authorized lines, all operating at 500 kilovolts (kV), include Pecém-II – Pacatuba C, Fortaleza II – Pacatuba C, and Pacatuba – Jaguaruana II.
The Pacatuba substation has also commenced operations. This development increases the capacity of the Northeast—a region rich in wind and solar power plants—to transmit power that had been restricted since August 15, when a blackout impacted 25 states and the Federal District due to equipment failures in a line located in the region.
The power outage led ONS to adopt more restrictive operations until measures ensuring system reliability could be implemented, thereby limiting the transmission of renewable power from the Northeast to the rest of Brazil. This practice is known in the electric sector by the terms “constrained off” and “curtailment.”
Marcio Rea, managing director of ONS, said that the new assets have increased power transmission from the Northeast submarket to the Southeast/Central-West by 12%, raising the capacity from 11,600 megawatts (MW) to 13,000 MW. The capacity for power export from the Northeast to the North has also been increased by 30%, from 4,800 MW to 6,000 MW.
Later this month, the Olindina-Sapeuçu transmission line, also at 500 kV, will become operational, further boosting the capacity from the Northeast to the Southeast/Central-West from 13,000 MW to 13,800 MW. “This will reduce the need for restrictions,” said Mr. Rea.
Mr. Rea acknowledged, however, that generation cuts will not cease entirely with the activation of new wind and solar projects. “It’s impossible to eliminate the cuts,” he added.
Mr. Rea also mentioned that ONS, the Ministry of Mines and Energy (MME), and the Energy Research Company (EPE) are exploring scenarios to expedite the first battery auction in the electric sector, initially scheduled for 2028 to 2029. The auction model is still under internal discussion. Batteries are considered an alternative to manage wind and solar power transmission during peak demand times, such as between 5 p.m. and 8 p.m.
At the end of the day, as solar photovoltaic generation exits the electrical system with the end of solar radiation, the system loses about 30,000 MW. Furthermore, peak hours mark a transition period for wind energy, as winds tend to be stronger at night. To meet this demand, ONS relies on thermal and hydroelectric power plants; however, during droughts, such as the current one, the operator aims to conserve reservoir use, which limits options.
With a battery system, wind and solar energy could be stored and injected into the transmission network as needed. However, the battery auction’s execution depends on the power regulator agency ANEEL regulating the subject.
ANEEL did not reply to Valor’s request for comment. Its 2024-2025 regulatory agenda includes “regulatory adjustments” in 2025 to incorporate storage systems into the electrical system.
The ONS managing director said that ONS, EPE, and MME are in discussions with ANEEL on regulation and believes that after rule definition and auction execution, a storage project could be operational within a year post-auction. “It’s a significant step forward and would further improve the issue of renewable energy cuts,” said Mr. Rea.
He said he believes that introducing batteries into the electric sector could start with an offer exceeding 500 MW of storage to facilitate market formation. However, the initial demand definition is up to the MME.
*By Fábio Couto, Valor — Rio de Janeiro
Source: Valor International