a Power cut off for about 20 minutes Which arrived in several states last Friday (28) is linked to a major problem in the Brazilian electrical system: the difficulty of transmitting energy between regions.
Even with a drought that mainly affects supplies in the south and southeast, Brazil eventually orders that factories in the north and northeast stop producing electricity. When this happens, hydroelectric plants expel the water without passing through the turbines, the wind (wind) turbines turn their blades in vain, while the consumer pays for the energy imported from neighbors or generated by the heat that needs to be energized.
The energy is disrupted
The cause of wastage is the lack of ability to transfer energy from one area with surplus electricity to another deficient area.
So-called “exchange restrictions” are a common problem in countries of continental proportions, but this can be minimized through more investment and planning, according to experts.
In Brazil, delays in the installation of transmission lines have exacerbated the situation.
The blackout occurred on Friday after a failure in the line that takes the electricity produced at the Belo Monte plant, in Pará, to the southeast and midwest. The case illustrates how inter-district distribution is vital to national supply.
On the same day, the National Electric Energy Agency announced Anil The electricity bill will be more expensive starting in June. The consumer measure bears the cost of operating the thermal plants and importing electricity.
Also on Friday, the government issued a warning Water (drought) emergency in five states South and Southeast. The lack of rain that affected these areas since last year has led to a decrease in the level of reservoirs There should be more control over the flow of weirs To avoid a worse blackout.
Areas that consume more than they produce
With the exception of Roraima, all states are linked by SIN (National Interconnected System). The network is divided into four sub-systems (or sub-markets): South, Southeast / Midwest, Northeast, and North.
The classification is different from the regional geographic division – Maranhão in the northern sub-system; Acre and Rondônia are located in the SE / CO subsystem.
SE / CO generates the most number and consumes the most energy. In March it was responsible for 52% of the national generation and consumed 58%.
The south also suffers from a deficit (it consumes more than it produces). As a general rule, both subsystems need to bring in electricity from the north or the northeast to meet demand.
Since last year, Brazil has regularly imported energy from Argentina and Uruguay.
Energy that depends on the time of the year
The northern sub-system produces redundant energy mainly in the first semester, when the rivers are high. The main source of generation in the region comes from “downstream” hydroelectric plants, which do not contain large reservoirs.
João Sanches, director of consultancy Trinity Energia, says the option to build river runoff stations, such as Belo Monte, avoid the larger environmental impacts of flooding large areas.
On the other hand, the generation was more dependent on the rain and flood regime of the rivers.
The northeastern subsystem also depends on the period of the year. Its largest generation occurs in the second half, when the winds drive production on the wind farm.
Lack of energy harnessing structure
The fact that the North and Northeast are able to produce excess energy in different seasons could provide for the shortage at other locations, or at least reduce the problem.
But transport between regions is against limited infrastructure. Without a grid to transmit more electricity, a portion of the excess energy is reserved in the region of origin.
When the transmission limit is reached and the subsystem cannot absorb its own energy, the ONS (National Electrical System Operator), a special body linked to the Ministry of Mines and Energy, orders the shutdown of the turbines, so as not to overload the grid.
That is, there is the potential for wasted energy.
What is the government saying
Questioned before TwitterThe Office for National Statistics has not responded to the number of times it has requested that the turbines be shut down due to transmission limits between regions in recent years. Nor did it provide an estimate of the energy wasted in these cases.
The Office for National Statistics acknowledged the problem and claimed “some complications, such as the transportation system lines planned for the Belo Monte plant integration, which were not fully implemented”.
According to the National Bureau of Statistics, “the installations that were missing from the Belo Monte plant integration system have been bidding for and are being implemented”.
The National Bureau of Statistics also stated that the transmission system has been expanded to the growth flow of wind and photovoltaic (solar) sources in the northeast and northern Minas Gerais.
EPE, a federal energy research firm also linked to the Department of Mines and Energy, said there was a delay in the haulage business awarded to Abengoa. The lines were expected to be operational by 2017.
“Failure to carry out these actions within the stipulated schedule implies restrictions on the operation of the transmission system, over the past few years, to the present day,” EPE said.
a Twitter Abengoa sought comment on the issue, but the company did not respond until this text was published.
Also according to EPE, work to expand the transmission system with completion scheduled for March 2023 will increase the export capacity of the North and Near East regions by 2.5 gigawatts.
What do the experts say
According to Diogo Lisbona, a researcher at the FGV Center for Regulation and Infrastructure Studies, transporting energy in vast regions is also a challenge to large global economies, such as the United States of America and the European Union.
Therefore, it is only natural that the country still suffers from limitations in this energy exchange between remote points.
Juliana Chad, Director of Prices at MegaWhat, says the difficulty of transporting excess capacity from the Northeast is relatively recent, due to the expansion of wind farms in the region.
“Before [o subsistema NE] It was much more than an energy importer. Now I was able to be an exporter, but the transmission lines are still under construction. “
For João Sanches of Trinity Energia, the problem we face comes from a lack of planning and investments in the medium and long term – especially in transmission lines and energy diversification.