Is Brazil’s electric power system ready for next summer?

The rise in average temperatures in the largest Brazilian cities is causing an increase in electricity demand. 

The forecast demand growth for this week is 5.8% and the increase for the month is set to be the highest in recent months, according to projections by national grid operator ONS.

The increase in load also reflects Brazil’s faster-growing economy. 

In view of a recent blackout - which is still under investigation - and the greater complexity of operating the system due to the expansion of distributed generation and intermittent sources in the energy matrix, the question is whether Brazil is prepared for a spring and summer with above-average temperatures, as meteorologists predict.

ONS and an analyst consulted by BNamericas rule out any major energy supply risk. 

"In terms of operation and meeting demand, we remain prepared to serve Brazilian society. The system is robust, safe and the scenario is favorable," said Luiz Carlos Ciocchi, general director at ONS, in a press release.

The favorable scenario is due to good conditions of the country’s hydroelectric reservoirs, whose storage levels stand at 85.2% in the south, 73.7% in the north, 72.6% in the southeast/center-west and 67.2% in the northeast.

The electricity matrix has 85% of its installed capacity from renewable sources - mainly hydroelectric - with massive growth in wind and solar energy expected for the next few years. 

This growth has prompted ONS to accelerate a modernization program that will facilitate the integration of more renewable sources into the system, the operator said in a statement.

Henrique Casotti, a partner at consultancy Genco Energia, pointed out that the heatwave that hit Brazil in late winter and early spring would have had less of an impact during summer. 

"In summer we have much more available humidity and cloud cover, which mitigates the situation in cases like this," he told BNamericas.

According to Casotti, even with a very hot September and a high load, hydro storage levels will not fall as much as they did in 2019 and 2020, probably remaining over 60% by the end of the year - a scenario he considers very comfortable.  

Casotti said he is not worried about the advance of distributed generation and intermittent sources.

"Of course, this creates operational challenges, but I don't think we have a problem today with so much generation slack in the system." 

Euclides Lourenço Chuma, a senior member at the institute of electronic and electrical engineers (IEEE) and a researcher at Linköping University in Sweden, warns that with high temperatures, water evaporates from reservoirs more quickly and the risk of system devices overheating increases. 

"Extreme situations always disrupt normal operations and need to be closely monitored by the technical teams," he told BNamericas.