Synergy with Hydropower Plants Boosts Biogas Production in Brazil

  • Feb 10, 2020
  • Inter Press Service

FOZ DO IGUAÇU, Brail, - Fomenting biogas production among agricultural producers may seem at first glance to be a distraction from the purpose of Itaipu, the giant hydroelectric power plant shared by Brazil and Paraguay, but in fact it is part of their energy business strategy.

“Protecting the quality of the water (in the reservoir) is essential for power generation,” explained General Luiz Felipe Carbonell, coordination director in Itaipu Binacional, the company that manages the power plant on the Paraná River, which forms part of the border between the two countries.

The efficiency of Itaipu, the second largest hydroelectric power plant in the world in terms of potential, has been proven by the record amount of electricity generated: 103 million megawatts/hour in 2016, which exceeds the best performance of China’s Three Gorges power plant, whose installed capacity is 60.7 percent higher.

While the Brazilian-Paraguayan plant has a potential of 14,000 MW, the potential of Three Gorges is 22,500 MW. But generation depends on water flow, turbine efficiency and demand.

Biogas production in southwestern Brazil is on the rise, mainly due to the use of livestock manure. In the west of the state of Paraná, part of whose rivers flow into the Itaipu reservoir, there were 4.2 million pigs, according to the 2017 agricultural census.

Sedimentation is a risk that can shorten the life of a hydroelectric plant, which in Itaipu’s case is estimated at 184 years. In addition to the quantity, it is necessary to consider “the quality of the sediments,” noted Marcio Bortolini, adviser to the coordination director.

Organic waste, like the manure from pig farming, drives the proliferation of especially harmful species, like the golden mussel (Limnoperna fortunei), an invasive species that appeared in the Itaipu reservoir in 2001, he explained.

The mussel from Southeast Asia often clogs pipes and brings turbines to a halt when it latches onto hard surfaces.

Bortolini described this situation when he took part in a Jan. 27-29 workshop on biogas for Brazilian journalists, organised by IPS and the International Center for Renewable Energy (CIBiogás), with support from the U.S.-based Mott Foundation.

“Without good water quality, several species of fauna will settle in and affect our reservoir and the machinery,” said Carbonell, one of the army officers appointed to Itaipu and the Brazilian government under President Jair Bolsonaro, who himself retired from the army as a captain in 1988.

Efforts to combat the golden mussel and protect water quality managed to reduce the population of the invasive shellfish and keep it under control, said Itaipu administrators during the workshop held at the CIBiogás facilities in Foz do Iguaçu, the main city where the power plant is located.

“Besides the golden mussel, a danger to our maintenance service, we have the freshwater hydroid (Cordylophora caspia), an invasive species that corrodes concrete, and therefore represents a physical danger to the dam,” said the general.

The main cause of these threats is organic waste, which is why “we use it to produce biogas and at the same time to improve the environment and the quality of life of the populace,” Carbonell told IPS at the plant’s facilities.

Therefore, disseminating biogas as a source of heat, biomethane and bioelectricity, and promoting other energy alternatives, such as solar, hydrogen and less polluting batteries, does not distract Itaipu from its business of generating hydroelectricity, he said.

The same is true with regard to the reforestation of the surrounding area, where 44 million trees have been planted, because it protects the environment and the reservoir by reducing erosion and maintaining the water table. These are measures that support water security, an indispensable factor for the business.

The general also mentioned the plant’s efforts to boost the well-being of the surrounding population, and said health conditions have improved as a result of the projects.

Itaipu runs several social, economic development and technological programmes. Electric vehicles, a biodiversity corridor, tourism, local development and child protection are part of this focus, as is the Federal University of Latin American Integration, installed within the Itaipu area.

“Cultivating Good Water” stands out as a wide-ranging programme, initiated in 2003, in which more than 2,000 public and private entities have been involved in more than 60 social, economic and environmental actions, including fish farming, medicinal plants, garbage recycling and recovery of more than 200 micro-watersheds.

The programme is based on the principle of caring for water in order to generate more electricity for longer periods and to produce biogas for energy, environmental and water quality purposes.

Biofuel production was increased at the initiative of Itaipu, in a mission transferred to CIBiogas, founded in 2013 as an autonomous, non-profit entity. Itaipu is one of its 27 partners, which include the United Nations Industrial Development Organisation (UNIDO) and the United Nations Food and Agriculture Organisation (FAO).

From a biogas producer’s point of view, the environmental benefits have more to do with the air than with the water.

For example, the stench of “raw” manure has almost disappeared on the farm where Ademir Eischer uses manure to grow hay, his main source of income.

With just three hectares of land that runs up against the highway in the small municipality of Entre Rios, Eischer – who also fattens 1,200 hogs – can’t expand his pig farming operation, and the field planted with hay almost reaches his house.

“I’ve been working in haymaking for a long time and decided to start producing biogas because of the smell. When the manure goes through the biodigester, it loses 70 to 80 percent of its odour and we gain a lot in terms of quality of life,” Eischer told IPS during a visit to his farm.

Biodigestion consists of extracting methane (CH4), hydrogen sulphide (H2S, mainly responsible for the bad smell) and carbon dioxide (CO2), which make up the biogas, from the manure that can then fertilise the soil without the pollution and smell of the gases.

Methane, which is removed in much greater proportion than the other gases, is 21 times more aggressive than carbon as a greenhouse gas that warms the planet, which is why its extraction and use as a source of energy contribute greatly to mitigating the climate crisis.

Eischer is one of the 18 pig farmers whose biogas generate almost all the electricity consumed by the municipal government of Entre Rios do Oeste, population 4,600, which inaugurated its own mini power plant in July 2019.

Another local pig farmer and biogas producer, Claudinei Stein, highlighted other benefits: the “reduction to almost zero of mosquitoes” that used to pester him and his employees on the farm, while posing the risk of transmitting diseases.

In addition, the manure minus the gases has improved the fertilisation of the soil where he grows soybeans and corn on his 12 hectares.

Pedro Colombari says that with the bio-fertiliser resulting from biodigestion he has managed to improve his pastures to the point of fattening 10 cattle per hectare per year – quite a feat in a country where, on average, farmers only raise a little more than one cow per hectare.

“Now I’m trying to double that productivity on an experimental two hectares,” with more intensive fertilisation and irrigation, he told IPS.

His 400-hectare farm, where he raises 5,000 pigs and 400 head of cattle and grows soybeans and corn, generates its own electricity using biogas, in a microgrid in which several generators, using varied sources and batteries, can operate together and outside the main grid, offering greater energy security.

Register for access to the Energy news and press releases