One farmer in India shows how turning the gases emitted by cow dung can become a clean, renewable fuel that saves him money, increases his productivity, and boosts his profits.
Parshottambhai Shanabhai Patel, 65, says the biggest favor the people of his village did for him “was saying they would no longer put up with the stink from my cowshed at the entrance of the village.”
Reluctantly in 1994, Patel shifted his eight animals to his three-hectare (7.4 acre) farm 3 kilometers (1.9 miles) away from his village in Gujarat State’s Anand district. The district is where the Indian dairy cooperative AMUL started the country's "white revolution," a hugely successful grass-roots movement that has helped turn India into the world’s largest milk producer, with 2.5 million liters (660,000 gallons) of milk collected daily from more than 1,176 village cooperatives.
Now Patel's contentious cow dung could spark a revolution of a different kind.
After a decade of practicing organic farming, thanks to training provided by the Gujarat government-run Navsari Agricultural University, Patel decided in 2009 to push his farm even further into the green by building his own biogas plant.
With technical guidance from the university, he constructed a six cubic-meter (212 cubic foot) brick-and-mortar underground plant near his cowshed and connected it to his existing 12 horsepower irrigation pump. By turning the gases emitted by cow dung slurry into a clean, renewable fuel that Patel uses to run his irrigation system, the plant saves him money, increases his productivity, and boosts his profits.
Experts say biogas plants like Patel's are easy to build, operate, and maintain. And in a country dealing with changing rainfall patterns, and where only 35 percent of agricultural land is irrigated, they could transform the lives of India's small farmers.
Biogas plants, or digesters, work by encouraging the breakdown of organic matter (cow dung, in Patel's case) by bacteria in the absence of oxygen. The resulting methane gas can then be stored and burned as fuel. Each day, Patel's plant converts the 200 kg (440 pounds) of dung his livestock produce into 8 to 10 hours of power. It takes 30 kgs of dung to generate one cubic meter of gas. "But, yes, collecting all that dung from the cowshed unfailingly every day is highly labor intensive," he admits.