Lack of rain turns on warning signals and can affect your electricity bill

Rains below the historical average in recent months and the prospect of shortages ahead have raised alarm bells in the electricity sector, leading the National Electric System Operator (ONS) and the government to take measures, such as activating thermoelectric plants and saving water from reservoirs. of hydroelectric plants. The objective is to preserve volume for this year and 2025.

The result could be higher electricity bills for consumers down the road. Powered by coal, gas and other petroleum derivatives, thermoelectric plants produce energy that is generally more expensive than that from hydroelectric plants and other renewable sources. The more they are used to save reservoirs, the greater the cost that will sooner or later be passed on to tariffs.

The situation at the moment is still relatively calm, although the so-called “wet period” – which begins around November – has seen rainfall below the historical average in the Southeast/Mid-West (SE/CO) subsystem – it is the main of the country, as it concentrates around 70% of the water storage capacity of the National Interconnected System (SIN).

According to the ONS, the level of reservoirs in the Southeast/Central-West is approximately 65% ​​of maximum capacity – the second best level in the last 12 years, only below the March 2023 average (83%).

The danger is further ahead – more precisely, around May, when the “dry period” begins. In a report released in February, the ONS reported that, in the worst case scenario, SE/CO dams will be at just 36% of capacity in July – which would be the fifth lowest level this century.

In a more recent projection, the Operator reported that the so-called “stored energy” in the same dams could be at 45.5% in August, in the worst case scenario – somewhat below the levels of the same month in 2023 (79%) and 2022 (56 %), although above the levels observed between 2017 and 2021. In the best scenario for August, the ONS projection is for storage of 54.1%.

The drop in reservoirs is a concern because hydroelectric plants are still responsible for around 65% of the energy generated in the country. In recent years, solar and wind arrays have gained space in Brazil, but hydro generation remains the majority. And it has the advantage of guaranteeing stability in supply, unlike plants that depend on wind and sun to operate.

To reduce the impact throughout this year and in 2025, the ONS has already activated some thermal plants. They are turned on at the end of the day, when it is not possible to generate solar energy. According to the Operator, the additional fee is low and does not impact the fare. However, the body reinforces that tariff issues are the responsibility of the National Electric Energy Agency (Aneel).

Another ONS guideline was the reduction of water output at the Jupiá and Porto Primavera hydroelectric plants, located on the Paraná River, between São Paulo and Mato Grosso do Sul. The measure was accepted by the Electric System Monitoring Committee (CMSE), coordinated by the Ministry of Mines and Energy.

The ONS forecast with this measure is to preserve 11% of storage in the Paraná Basin until August and around 7% in the total in the Southeast/Central-West. This decision helps explain the improvement in projections in relation to what was expected for July.

“We will take the necessary measures to guarantee the energy supply and maintain the level of the reservoirs. The electricity sector must always be attentive to avoid unforeseen events and prioritize consumer safety”, stated Minister Alexandre Silveira.

Brazilian electrical system is hostage to the climate, says expert

Adriano Pires, director of the Brazilian Infrastructure Center (CBIE), criticizes the vulnerability that the Brazilian electrical system has to the climate. For him, even the growth of wind and solar arrays is not enough to break this dependence – they all end up being hostage to water, sun or wind.

“For a long time now, the Brazilian electrical matrix has been increasingly hostage to the climate. What saves Brazil from having a blackout is dispatchable (scheduled) energy, plants powered by coal, petroleum, oil, natural gas or nuclear energy, and thermal plants, especially those powered by gas”, he argues.

The effect of this falls on the consumer’s pocket, explains Pires. “Thermal is more expensive, and this affects tariffs and inflation,” he says. The path, he argues, is a policy centered on diversified matrices and better managed.

“Our matrix is ​​already 85% clean. What we need is to have electricity policies that bring security. Instead of turning on the more expensive thermal plants in an emergency, it would be better to manage them throughout the year. The cost would be lower,” he says.

Paulo Cunha, consultant at FGV Energia, considers ONS’ preventive decision to bring forward thermal dispatch to be prudent. However, he considers that, by doing so, price distortion may occur.

“When these thermal plants are turned on, the short-term price is artificially lower because this additional cost is shared by everyone. But it is a distortion. It’s just the impression that it’s lower,” she says.

“The reservoir level is comfortable and there is no supply crisis in sight this year. What happens is that the climate does not indicate abundant rain and we see that demand increases”, says the consultant. He highlights that solar and wind sources have become very relevant in contributing to energy generated in the country in these cases.

Aneel lowered tariff flag values

Contrary to ONS precautionary measures, Aneel – which regulates the sector but does not operate energy production – approved in March the reduction of reference values ​​for tariff flags.

Flags are additional amounts charged to the electricity bill when the system is under stress: the greater the use of thermoelectric energy, the greater the extra charge. In this way, the flags serve both to pay the higher generation cost and to signal to the consumer the need to save energy.

The signal that Aneel gives by reducing the flags, therefore, is that the situation is comfortable. On its website, the agency says that the measure “was approved due to the favorable hydrological scenario, the large supply of renewable energy in the country and the relief seen in the price of fossil fuels on the international market.”

The green flag – currently in force – means a favorable situation, with no extra tariff for the consumer. The value of yellow, the first alert level, was reduced by almost 37%, from R$29.89 per megawatt/hour (MWh) to R$18.85. Red 1 went from R$ 65 to R$ 44.63 per MWh (drop of 31.3%) and red 2, from R$ 97.95 to R$ 78.77 per MWh (reduction of almost 20%) .

Wanted by People’s Gazette to comment on this decision, Aneel said the review of additional tariff flags is updated based on the history of previously realized values ​​and the operating dynamics of the electrical system over the next year, considering various matrices.

“This operation (review) considers the characteristics of the Brazilian electrical matrix, the variations in wind and solar generation over time, as well as the atmospheric effects that influence the rainfall regime and, consequently, the dispatch of hydroelectric and thermoelectric plants” , said Aneel in a note.