"The idea came to a group of schoolmates and me in 2014, but we never thought it could become a reality," says Sebastián Ieraci, 23, as he points to a multitude of photovoltaic solar panels shining on the roof of the Antonio Devoto High School in the Argentine capital.
"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.
The increased frequency of climate-induced weather extremes and public opinion pressure are forcing even major fossil fuel exporting countries in West Asia to make a big push towards renewable energy.
The intense white brightness of the salt flats interrupts the arid monotony of the Puna in northwest Argentina, resembling postcards from the moon. Beneath its surface are concealed the world's largest reserves of lithium, the key mineral in the transition to clean energy, the mining of which has triggered controversy.
"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.
Dogged by intractable air pollution debilitating large northern swathes from mainly urban vehicle emissions, India earlier this year announced targets for a 40 percent non-fossil component in its fuel-mix by 2030 as part of its Nationally Determined Commitments (NDC) to the Paris accord on climate change. It aims for full electrification of public transit systems and of one-third private vehicles by 2030.
"They called me crazy" for fencing in the area where the cows went to drink water, said Elias Cardoso, on his 67-hectare farm in Extrema, a municipality 110 km from São Paulo, Brazil's largest metropolis.
The Inter-American Development Bank (IDB) is in the process of modernising the social and environmental safeguards that govern the financing of projects considered vital for the construction of sustainable infrastructure in the Latin American region.
In Argentina's Puna region, at 4,000 metres above sea level, the color green is rare in the arid landscape, which is dominated by different shades of brown and yellow. In this inhospitable environment, daily life has improved thanks to a system of piping water downhill from rock glaciers to local communities.
The sun's rays are also used to cook food and thus replace the burning of firewood and gas, improve the health of local residents and fuel the energy transition towards the use of renewable sources - the objectives of an enterprise in the southern Mexican state of Oaxaca.
"On moonless nights it was very difficult to walk around this town," says Celia Vilte, a teacher from San Francisco, a highlands village of just 54 people in the extreme northwest of Argentina whose centre is not a town square but 40 solar panels, which provide one hundred percent of its electricity.
"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.
Reyna Díaz cooks beans, chicken, pork and desserts in her solar cooker, which she sets up in the open courtyard of her home in a poor neighborhood on the outskirts of this town in southwestern Mexico.
Pigs, already the main source of income in this small municipality in southwestern Brazil, now have even more value as a source of electricity.
On the outer edges of Buenos Aires proper, where the paved streets end and the narrow alleyways of one of Argentina’s largest shantytowns begin, visitors can find the En Haccore soup kitchen.
"This is the best thing ever invented for the poor," says Emanuel del Monte, pointing to a tank covered in black tarps protruding from the roof of his house. It forms part of a system built mostly from waste materials, which heats water through solar energy and is improving lives in Argentina.
Children from the neighboring municipalities of Ovalle and Río Hurtado in northern Chile are harvesting rain and recycling greywater in their schools to irrigate fruit trees and vegetable gardens, in an initiative aimed at combating the shortage of water in this semi-arid region.