Cow dung for the climate

September 25, 2005

A model biogas project is creating a win-win situation for rural Nepalese, the industrialised world and the atmosphere.

The scheme recently won the renowned Ashden Award for Sustainable Energy and is already being replicated in some Asian and African countries.

It is calculated that gas generated from cattle dung in rural Nepal has lit around 140,000 kitchens, saving 400,000 tonnes of firewood, 800,000 litres of kerosene and preventing 600,000 tonnes of greenhouse gases from escaping into the atmosphere.

The project, known as the Biogas Support Programme, Nepal, (BSP), has been implemented in 66 of the nation’s 75 districts.

This at a time when most development work has come to a standstill in almost all districts because of the 10-year Maoist insurgency.

Money from gas

On the international front, the BSP has been able to “sell” the savings it has made in emissions of carbon dioxide and methane gases to industrialised countries. These nations can buy such “credits” to compensate for the extra greenhouse gases they produce over the allowances stipulated in the Kyoto Protocol, the global climate treaty.

Each BSP biogas plant is said to save some 4.6 tonnes of greenhouse gases from entering the atmosphere every year.

First and foremost, a plant will save the carbon dioxide that would otherwise have been emitted by the burning of firewood. And by burning the cattle dung’s methane, a more potent greenhouse gas than CO2 is prevented from entering the air.

The byproduct from a plant’s digester is compost manure which will contribute nothing to the greenhouse effect.

“We have not even been talking yet about the savings of the carbon that is absorbed by the trees, and then sparing the trees from being used as fuel because of the biogas plants,” says Sundar Bajgain, BSP’s executive director.

This saving has yet to be sold as credit.

Kyoto clean-up

The trading of greenhouse gases has been made possible by the Clean Development Mechanism established under the United Nations Framework Convention on Climate Change.

In line with this mechanism, the World Bank is buying US$5m of greenhouse gas emissions saved by the BSP.

The project is also looking to clinch more deals with other western institutions as it plans to add 200,000 biogas plants by 2009 in rural Nepal, where cattle-raising is the basic means of livelihood.

“There are other banks in the Netherlands that are keen to buy carbon credits from Nepal’s BSP,” says Jan de Witte, former chief of the Dutch development agency SNV’s office in Nepal.

The German bank KFW is also keen on buying carbon credits, adds Sundar Bajgain. All these deals are more likely to materialise now that Nepal has registered its ratification of the Kyoto Protocol with the UN.

Ready to roll

While the bureaucracy may take time to move, the biogas plants are already rolling.

It is a simple and natural technology – dung goes in, gas comes out. Here is how: bacteria that come with the dung from the cow’s stomach break down the waste in an underground air-tight digester.

In the absence of oxygen, the mixing of cow dung with water leads to a reaction that produces a gas comprising up to 70% methane and the remainder CO2.

The digested slurry flows to an outlet tank and ends up in the compost pit, while the gas is tapped from the top of the dome with a pipe that ends in the burner of the kitchen stove.

BSP officials say that quite apart from the issue of carbon credits, the technology has eased the lives of rural women who otherwise choked and developed respiratory problems because of the firewood they would normally use in their kitchens.

Buoyed by the £30,000 (US$54,000) Ashden Award for “outstanding achievement in using sustainable energy to improve the quality of life and protecting the environment”, the BSP has been testing modified designs of biogas plants in high altitude locations such as Solukhumbu, in the Everest region.

“The results are promising,” says Bajgain. “We got good gas generation even in the winter.”

The Dutch aid group SNV, the BSP’s main backer, is now replicating the project in Bangladesh, Vietnam, Cambodia and some African countries.

The other attraction of the biogas project is the jobs which it produces. In Nepal, there are already 57 private companies specialising in digester construction, and developing ancillary industries. This gives employment to 11,000 Nepalese.

A report prepared by the European Biomass Industry Association and the conservation group WWF states that switching to farms producing ethanol and other biomass fuel could create hundreds of thousands of jobs while reducing one billion tonnes of carbon dioxide emissions each year.

“Biomass currently provides only one percent of the power needs of rich countries, but could provide up to 15% by 2020,” the report said.

Unlike fossil fuels, burning biomass, like biogas from cow dung, is generally considered to be carbon neutral.


Tags: Biomass, Renewable Energy