Now that's hot air!

Every few weeks the Green School principle invites parents to a morning meeting. It is an opportunity for the parents to learn about school initiatives and for general communication. (Apparently all young organizations, no matter how ideal, have growing pains!) The first meeting I went to reminded me too much of being at work so I shied away until today. And I'm so glad to have gone!

The school's operations manager is an Indian engineer named Arjay. His team keeps the buildings and grounds safe and he develoops green technologies. Today he unveiled a system that converts dung from the school's livestock into cooking gas for the school cafeteria. Arjay has been working on this system under the mentorship of a man who has built over 800 in India. Apparently there are large Indian office buildings harnessing methane from food waste.

There were about 40 people including visitors from other schools and a reporter who were taken to see two large yellow drums (see picture above) with a fuel hose running about 20 feet to a gas cooker. Arjay explained that when methane gas is burned it converts into carbon dioxide and water which is less toxic than methane itself. It can be used in the same way we would use propane or natural gas for cooking.

To capture methane one only needs a source of gas (food or dung) that is made into a "slurry" by mixing it with water. The slurry is fed into the large tank and then heat from the sun releases the methane which is caught by the smaller tank at the top and held until it is needed (for example, when the stove is turned on). The byproduct is fertilizer which comes out of a tube in the lower part of the system. And when the gas tank gets low, instead of a trip to the fuel station, look for the closest cow! Food waste or dung of any source will do.

As he was talking, Arjay asked one of his team to fetch some dung from one of the school cows. It was brought and Arjay poured some water into the bucket. One of the parents asked how they mix the slurry and Arjay said “by hand.” What I witnessed next was certainly a surprise because I wasn't prepared for how literal he was! Elbow deep in cow dung soup - there was Arjay stirring! He pulled out little bits of hay informing us that the hay should be removed as it clogs the system. Once the slurry was mixed to his satisfaction, in it went into the system ready to bubble into usable cooking fuel

What an amazing use of what is probably the epitome of garbage! It makes total sense to use the methane gas for cooking, particularly when you consider that many families in the developing world are unable to afford fuel for cooking and they rely on collecting little bits of wood for cooking fuel. But I have to admit, I stay on the side of theory here – I have no inclination to bury my arms in dung for any purpose. But there are an awful lot of cows around here (whose purpose I can't exactly figure out since Bali is overwhelmingly Hindu and they don't eat beef and they don't use them for milk) just doing their business and wasting hot air...

Riah