Biogas the cheaper, energy saver

FREDERICK KEBADIRETSE
Staff Writer | Friday April 9, 2010 00:00

 

After all, the advantages of using biogas as a form of energy are numerous. Besides saving him a lot of money, as he no longer needs to pay any electricity bills, he can save energy and does not have to contend with power outages.

This scenario is especially ideal in the rural community of Pitsane where people prefer to use firewood for cooking. However foraging is not Nyatshane's lot either as he explains how the gas is produced; '' If the gas level goes down, I just have to put in a little waste inside, like food leftovers, and when fermenting, they produce the gas,' he said.

Nyatshane said he does not throw away any organic waste at his house as he puts it into his gas reactor to produce gas. 'I use everything from vegetable peels, porridge and rotten fruits in my reactor, so what most people consider crap or waste is important to me,' he said.

It also, explains Nyatshane, has its own advantages as compared to Liquified Petroleum Gas (LPG) which is usually sold in cylinder bottles. 'It is cheap, and apart from that it is safe to use and can be used by everyone even kids,' he said.

Nyatshane constructed his home biogas plant three years ago after he learned about the alternative energy source from his employers at Masterprint in Lobatse. He used cow dung to produce the gas and connected pipes to ferry it to he house.

While the initial cost of constructing a biogas reactor at home ranges from P5,000 to P8,000 Nyatshane has no regrets as he explained that it is actually cost serving as from then onwards, power is basically free of charge, with the plant itself enjoying a lifespan of 25 years.

 Nyatshane encouraged Batswana to explore this alternative energy source as it is economically viable and reliable at the same time. ' It has saved me a lot of money and if more people can use it, we can preserve our environment and save energy and money,' he said.

He explained that the waste used in the plant does not pollute the environment as it is sealed tightly in a container, and when fermenting, there is no smell at all and the gas does not produce any adverse smell.

He said in cold temperatures when the fermentation process is slow, he usually mixes food leftovers with a little warm water to speed up the process and thus produce more gas. He said if he does not use the gas for a lengthy period of time, it overflows and the waste can also overflow but he can still use this excess waste to manure his plants.

Biogas, which is mainly methane, is a gas produced from the digestion of organic materials in an oxygen-free environment (anaerobic fermentation).

The gas is mainly composed of 60 to 70 percent methane, 30 to 40 percent carbon dioxide and a low amount of other gases. Biogas produced in anaerobic digesters is burned to generate clean, renewable energy. The main components of biogas are carbon dioxide and methane.

A biogas reactor uses feedstock, which usually contains biomass material mixed with liquids to facilitate the anaerobic process. Feedstock can be animal waste, plant matter, industrial effluent and even sewage.