October 31, 2009
Biogas Could Power a Blacked-Out Pakistani Village
contributor: Rob Goodier
During the hot summers temperatures can rise above 120 degrees F in Punjab, the provincial home of nearly half Pakistan’s population. Rolling power blackouts lasting eight to 12 hours per day afflict rural villages along the region’s river valleys. When the electricity fails, so do all the refrigerators, fans and water pumps.
There may be a solution in the pastures surrounding one village on the outskirts of the city Burewala: cow manure. With some ingenuity and only a little investment, the town could build biogas-powered electricity generators. That’s the vision of Rashid Ali, an engineering student in Lahore and Pakistan’s vice chair of the Student District Operating Board at ASME International.
Ali derives theplant’s design from proven technology used on small scales around the world. In a sealed, airless container, microbes in the manure break it down and create the gases carbon dioxide and methane, which can fuel an electrical generator. Farmers can return the spent mixture of manure and water to the fields as fertilizer for the wheat, corn, rice and sugar cane that underpin rural economies in Punjab.
There are precedents for the idea. Biogas is now used in India, on Punjab’s eastern border, and it is a budding resource in Pakistan itself. Villagers usually collect it in small canisters outside of homes and pipe it into gas stoves for cooking.
The details of a biogas power plant for a village are still sparse. Ali posted his idea on the Engineering for Change Web site as a challenge that needs further study and funding. He is not sure how much manure could be collected, how much electricity a plant could generate, or how much it could cost.
On the other hand, farmers already collect manure from the fields to dry and burn. Diverting it from their fires to ferment in a biogas plant would call for a slight cultural shift. “It will require some effort to convince them that the manure will not be wasted, that it will be used to make electricity,” Ali said.
The town’s electricity needs are low. Most households do not have power-guzzling appliances other than TVs and refrigerators. Many need power only for lights, water and cell phone chargers. “Since the electricity consumption isn’t a lot, so many houses can benefit from this,” Ali explained.
For more information on the biogas project, contact Ali at alir2 (at) asme (dot) org and see the Burewala Biogas Power Plant Project on this site.