The increasing productivity with which humankind generates waste has gained at least one sustainable counterpart: the extraction of biogas from landfills, a growing activity in Brazil.
Standing in front of a blue flame on her stove, getting ready to brew coffee, Mayra Rojas says the biodigester built in the backyard of her home in western Cuba has become a key part of her daily life and a pillar of her family's well-being.
The multitude of solar panels stands out along a dirt road in an unpopulated area. Although located just an hour's drive from Buenos Aires, the new solar park in the municipality of Escobar is in a place of silence and solitude, symbolic of the difficulties faced by renewable energies in making inroads in Argentina.
Three giant concrete cylinders with inflated membrane roofs are a strange sight in the industrial park of Zárate, a world of factories 90 kilometers from Buenos Aires that heavy trucks drive in and out of all day long. They are the heart of a plant that is about to start producing energy from agro-industrial waste, for the first time in Argentina.
First came sugar. For four centuries, it was the main sugarcane product in Brazil. But since the 1970s sugarcane has grown and diversified as a source of energy: ethanol, electricity and biogas.
The number of victims of serious burns, some fatal, has increased in Brazil. Without money to buy cooking gas, the price of which rose 30 percent this year, many poor families resort to ethanol and people are injured in household accidents.
Yunia Cancio cooked with firewood until a few years ago, when a biodigester was built on her family’s El Renacer farm in Cabaiguán, a municipality in the central Cuban province of Sancti Spíritus, under the Biomass Cuba project. That change meant a lot for her family’s quality of life, but it was not the only one.
"Biogas is worth gold to us, we can no longer live without it," Claudete Volkswey, a poultry farmer in the municipality of Toledo, in the southwestern state of Paraná, Brazil, said enthusiastically about the new source of energy that has allowed her to get a good night’s sleep again, because she no longer has to get up to stoke the fire every two hours.
Rosa Manzano carefully arranges pieces of wood in a big mud igloo that, seven days after it is full, will produce charcoal of high caloric content.
"It used to be complicated, I would have lunch with the flies," recalls Pedro Colombari, laughing, on his 400-hectare farm where he fattens 5,000 pigs and raises 400 cattle outside of a small town in southern Brazil.
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.
Nepal’s future may not be in hydropower, as most assume, but actually in the dung heap. A new industrial-scale biogas plant near Pokhara has proved that livestock and farm waste producing flammable methane gas can replace imported LPG and chemical fertiliser.
"They're the ideal duo," because the combination of solar and biogas sources makes it possible to provide electricity around the clock, one during the day and the other at night, says Anelio Thomazzoni, a pig farmer who has become a producer of clean energy in southwestern Brazil.
"Biogas is the best energy, it has no contraindications," and if you combine it with solar it becomes "the best energy business," at least in Brazil, says Anélio Thomazzoni.
The state of Santa Catarina in southern Brazil is the largest national producer and exporter of pork and this year it also leads in exports of chicken, of which it is the second-biggest producer in the country.
Biogas has the potential to provide 36 percent of the electricity consumed in Brazil or replace 70 percent of diesel if purified as biomethane, according to the Brazilian Association of Biogas and Biomethane (Abiogas).
Romário Schaefer is fattening up 3,300 pigs that he receives when they weigh around 22 kg and returns when they reach 130 to 160 kg - a huge increase in meat and profits for their owner, a local meat-processing plant in this city in Brazil.
Pigs, already the main source of income in this small municipality in southwestern Brazil, now have even more value as a source of electricity.
Black plastic pipes, readily available on the mainly empty shelves of Cuba’s shops, distribute biogas to homes in the rural town of La Macuca, buried under the ground or running through the grass and stones in people’s yards.
“We want to make history," agreed the teachers at the Chiquinho Cartaxo Comprehensive Technical Citizen School. They are the first to teach adolescents about generating power from bad weather in the semi-arid Northeast region of Brazil.
Promoting the widespread use of innovative technologies will be critical to combat the hostile effects of climate change and reduce greenhouse gas emissions, and many African countries are already leading the way with science-based solutions.