Curitiba landfill becomes a solar energy park – 04/14/2023 – Environment

The space where 12,000 tons of garbage produced in Curitiba and its metropolitan region are deposited has gained a new destination in recent weeks: being a solar energy park. Baptized Pirâmide Solar da Caximba —name of the sanitary landfill that operated at the site for 21 years, until 2010— the project was inaugurated with 8,600 photovoltaic modules, which occupy a quarter of the land.

According to an estimate by the City of Curitiba, responsible for the installation, these panels should supply 30% of the electricity consumption of municipal public buildings. With this, the idea is to reduce by up to R$ 3 million per year the expenses with electric energy.

Delivered at the end of March, on the city’s 330th anniversary, the system distributes the generated energy to the electric power company, which then deducts the costs from the city’s bill. The municipal administration also foresees solar panels in bus terminals and on the road to lower expenses.

According to the municipal secretary of the Environment, Marilza Dias, the cloudy and cold climate of Curitiba in part of the year will not be a problem. She claims that the process benefits from sun and heat, but also works only with light. “What generates energy is light, so there is good viability, especially if we compare it to countries with less sun, like Germany, which already use this system a lot”, she says.

“We transform a liability into an environmental asset”, completes the secretary.

The idea was born in 2012, when Rafael Greca (PSD), the current mayor, was a candidate and wanted to propose a way to reuse the deactivated space.

Due to the possibility of moving the ground on the “hill” (due to its shape, it inspired the new name of “pyramid”), it would not be possible to make excavations, so concrete rings were used for support, which adapt in case of changes in the terrain. .

The implementation, which cost the municipality BRL 28 million, lasted one year and also received an incentive of USD 1 million (about BRL 5 million), through an award granted by the C40 Cities Network, an initiative aimed at reducing carbon emissions in municipalities.

Waste treatment

Since the “retirement”, Caximba has had to comply with environmental rules and actions foreseen in the plan to close its activities, which includes the treatment and constant monitoring of the generation of leachate (a liquid derived from the decomposition of garbage) and the release of toxic gases. . This work involves 33 professionals and costs BRL 600,000 a month, according to the city hall.

The leachate treatment involves a system called “wetlands”, ponds with aquatic plants that reduce the pollution in the liquid resulting from the degradation of solid residues, the leachate.

The quality of the process was part of the study by biologist Juliani Prestes, master and doctoral student in ecology and conservation at UFPR (Federal University of Paraná). For her analyses, she uses freshwater bivalves (a species of mollusk) that act as bioindicators.

“They respond to contamination by altering their physiology and accumulating substances, making it possible to assess the impacts of the leachate on organisms in the aquatic environment”, says the researcher. According to the study, on-site treatment proved to be efficient.

Leila Maranho, professor and postdoctoral student in ecology and conservation at UFPR, has been monitoring Caximba since 2009 and says that the evaluations are positive. “The leachate is monitored monthly and at various points throughout the landfill area”, she says.

The Secretary for the Environment emphasizes that the actions were foreseen until 2035, but will be adapted according to the landfill stabilization process. “As long as there is leachate and gas generation, it is considered an environmental liability”, explains Marilza.

new destination

After the deactivation of Caximba, the waste generated in Curitiba and neighboring cities was sent to two landfills: one at CIC (Industrial City of Curitiba), with its maximum capacity almost reached, and another at Fazenda Rio Grande, a city in the metropolitan region, which has the capacity to receive garbage for another eight years, predicts Conresol (Intermunicipal Consortium for the Management of Urban Solid Waste).

The next plan is to eliminate the allocation of raw waste (without treatment) to landfills. For this, studies evaluate the transformation of non-organic and non-recyclable waste into waste-derived fuel (RDF). The goal is for it to replace the use of fossil fuels in cement industries in the region.

Marilza says that, in Curitiba, the waste that is not used in associations of recyclable material workers is already being transformed into fuel for cement plants.

“We hope to complete the feasibility studies in May and expand this waste management, which integrates a series of actions to combat climate change”, says the secretary.

_{The Planeta em Transe project is supported by the Open Society Foundations.}