Rio de Janeiro is the state that emits the most greenhouse gases from thermoelectric plants in the country

According to information from the Energy and Environment Institute (Iema), the state of Rio de Janeiro is the state that emits the most greenhouse gases through thermoelectric plants in Brazil. Its emission corresponds to 18.9% of the national total, which is equivalent to 6,172 thousand tons of CO2.

In second place appears the state of Santa Catarina (12.9%). Then Maranhão (12%), Rio Grande do Sul (11.9%) and Amapá (10.8%). The survey was based on emissions in 2020.

The survey also highlighted that, alone, the state of Rio de Janeiro produced 25% of all the energy coming from plants of the National Interconnected System (SIN), which supplies much of the country.

“The high concentration of electric thermogeneration in a few units of the federation is noteworthy: 81% of the electricity inventoried here was produced in only eight states, with three of them (Rio de Janeiro, Amazonas and Maranhão) accounting for 52% of the total electric energy. fossil produced in the country”, points out the research.

In all, the 72 public service fossil fuel thermoelectric plants that operate in the National Interconnected System emitted 32.7 million tons of carbon dioxide equivalent (CO2e).

According to the study, “these emissions were concentrated in a relatively small number of thermoelectric plants: 49% of the greenhouse gases emitted in 2020 were the responsibility of only ten plants – six of them use coal as their main fuel and another four use natural gas. Natural”.

The equivalent carbon dioxide, according to the Instituto de Pesquisa Ambiental da Amazônia (Ipam), “is the result of multiplying the tons of greenhouse gases emitted by their global warming potential. For example, the global warming potential of methane gas is 21 times greater than the potential of carbon dioxide (CO2). So we say the CO2 equivalent of methane is equal to 21.”

For Diogo Lisbona, a specialist in electric energy and a professor at the Fundação Getúlio Vargas (FGV), a question of emissions is how efficient is the thermal plant and whether it is an open cycle, which does not take advantage of steam and ends up wasting energy that could be used to generation, or closed cycle (or combined), more efficient and less polluting than open cycle.

“If she consumes more, she emits more pollutants. Older thermal plants tend to be more polluting. There are thermals that are already reaching their useful life ”, she points out, complementing with an alert. “Rio de Janeiro should pay attention to this. The state must be a strong stakeholder so that new contracts require lower issuance rates,” she argues.

Professor of energy planning at the Federal University of Rio de Janeiro (UFRJ), Diego Malagueta explains that thermoelectric plants can have very different configurations and purposes. “The more complex, the more robust it is, the more efficient it will be, the cheaper the electricity it will generate”, he explains.

Iema also pointed out that the generation of the 72 fossil fuel thermoelectric plants inventoried in 2020 was 54.1 Terawatt-hours (TWh). Of this amount, 76% were produced from natural gas, 20% from coal and 4% from petroleum derivatives, fuel oil and diesel oil.

There were 36 plants powered by natural gas as the main fuel, 17 by fuel oil, 11 by diesel oil and eight by mineral coal.

For Diogo Lisbona, the data show that Brazil still needs to advance in terms of the installed capacity of energy sources and have more options for less polluting sources.

“These numbers reflect the installed capacity of this source, which is widely used in years of crisis. We should try to move in the direction of decarbonization. Make sure that fossil fuels do not gain space in the matrix. Not to mention that renewable sources are more competitive. It doesn’t make much sense to hire more expensive and polluting energy”, he argued.