Where there's muck......

While on holiday in India recently I visited an interesting renewable energy project; a small scale harnessing of methane gas from cow manure for supplying domestic cookers. This was a simple structure, like a small gas holder.  Cow manure was fed into a chute with enough water to make it flow into the gas holder, which was no more than a closed metal cylinder about a metre and a half in diameter and two metres tall.  Gas was given off and stored in the cylinder which went up and down according to the volume of gas and the weight of the metal cylinder created the pressure to feed the gas to a methane cooker ina a nearby house.  The spent manure flowed out by gravity and was used as fertilizer.  All very simple.  Apparently it needs about ten cows to provide a constant supply of gas for cooking for an average family but as it was clearly a rural application it would fit well into small communities who had livestock.  There is nothing new about this concept except it is being rolled out quite extensively to provide much needed fuel in remote areas where a mains supply will never reach.  Not only does it provide gas but it is environmentally friendly by reducing the harmful effects of methane being released into the atmosphere.

Having seen this I was really fascinated to read, shortly after my return, a report about Hewlett-Packard’s plans to power data centres from energy generated from cow manure.  They calculate ten thousand cows will produce enough manure power to run a typical data centre.  This gives a whole new meaning to the term ‘server farms’.

This idea illustrates the progress made in the use of gas produced from waste.  Whilst manure produces gas easily, more complex processes are available to turn most waste products into gas to run power generation plants.  Such plants are ideally suited for providing power in rural communities where mains electric is not available, as well as utilising waste where it occurs.