Sunday, December 28, 2008

A long overdue 'green' solution

Those of you who've lived or traveled in the Third World will know all too well the many problems faced by rural (and some urban) dwellers.

- Sewage works are often not available at all, resulting in a 'night soil' bucket operation that makes the area smell to high heaven;

- When sewage treatment works are available, they're often no more than concentrators of sewage from an area, which is then discharged into the nearest river or stream. Those above the discharge point are OK, but the water downstream is polluted for many miles;

- Electricity and/or gas supplies are often not available, and when they are, they aren't exactly reliable: so much of the cooking and heating is done with firewood, or (for those wealthy enough to buy it) charcoal or coal. This denudes the surrounding landscape of trees;

- Fertilizer is very expensive, often too costly for poor rural people to afford, with negative consequences for the yield from their fields.

In two recent reports, the BBC describes projects in Nepal and Rwanda that address all of these problems simultaneously. It's very encouraging to read them.

In Nepal:

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.

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.

. . .

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.

. . .

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.

. . .

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.

Sounds like a very good idea, very well executed. A similar project in Rwanda also received the Ashden Award.

A Rwandan prison project, which reduces cooking fuel bills by using methane gas from inmates' toilet waste, has won a global environment award.

The Kigali Institute of Science and Technology has helped prisons cut their firewood spending by $44,000 (£25,000).

The residue sewage is then used as fertiliser on crops to feed each institution's 10,000 prisoners.

"Biogas kills two birds with one stone," Ainea Kimaro, the Ashden Award winning project head told the BBC.

Mr Kimaro received his $53,000 (£30,000) prize at a ceremony in London on Wednesday for underlining the vital role which small-scale sustainable energy can play in tackling both climate change and poverty in Africa, the award organisers said.

Most biogas plants are small, but Mr Kimaro's big tanks resemble giant brick beehives - constructed in a pit which is covered on completion.

Rwanda has a huge prison population with some 120,000 suspects awaiting trail for their alleged part in the 1994 genocide in which some 800,000 Tutsis and moderate Hutus were killed.

Five of the country's largest jails now boast biogas plants, either in operation or under construction.

At Cyangugu prison, with biogas now fuelling five of the nine boilers in the prison kitchen, their firewood bill has been cut by more than half.

"The firewood savings are excellent - they really make a difference for us," a Cyangugu prison warden said, adding that the odour-free compost had done wonders for the prison gardens.

"Look at all these bananas! This fertiliser really is the best," he said.

Mr Kimaro said the fact that the methane gas was generated from sewage had not put prisoners off their food.

"I myself I have a biogas plant in my house! It's a tropical solution to a tropical problem," he said.

Again, excellent news.

I wish more environmental organizations would put their weight and support behind such projects. Instead of marching in protest against first-world industry, which is largely impervious to their shouting, why not seek to actually do good instead of complain about the bad? I think their credibility would rise substantially if they could produce evidence of projects like these, that were helping to both reduce the environmental impact of humans and improve our lives, rather than simply moan and groan about what others are doing. Action speaks far louder than words!



reflectoscope said...

I reasonably believe that many of the users are not concerned with saving greenhouse gas emissions, but I am pleased to learn that there is such an elegant solution to the problem of freezing in the dark.

KD5NRH said...

Implementation may be long overdue, but both humanure composting techniques and methane harvesting have been around for a long time.

Old NFO said...

Excellent post, and it is nice to see technology being put to work to solve the third world issues, my only problem with it is; after a year or so, no one will be left that knows the tech, and it will degrade within a year or so, and the populace will be back to firewood and raw sewage.

Simeron Steelhammer said...

Methane tech has been touted since 2000 I know. There was a professor at the Univ. of California that came up with a way to make methane based fuel for gasoline and desiel engines that gave a 99% output of regular gasoline and desiel at about 10% the cost of a barrel of oil in 2000...but its never been implemented.

Another thing about the biogas plant I am curious about is this...

When the "fuel" for the plant "expires"...that is the bacteria don't have stuff to produce gas with (or the used up material is at the bottom or whatever)...can't the expired fuel ALSO be burned in a "firewood" manner (with little stench) as cow and buffalo patties have been used by Native Americans (and other native indians) for centuries?

I would be interested to find out if this even could be done or if the "fuel bladders" just keep getting filled and the bacteria just digest it all into gas.

I didn't see where that was addressed anywhere (or that I could look up).

It is a thought though and would further add benefit to this system.

Andrew said...

The reason that cow patties make such good fuel is that they are essentially packed cellulose (grass). Human waste is not.