- Australian engineers have created an electricity generator
fuelled by decomposing bananas, and hope to build a full size fruit-fired
power station.
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- At present, much of Australia's annual banana crop goes
to waste, because the fruit are too bruised or small.
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- But rather than just letting them rot, the researchers
would like to put the rejects to good commercial use.
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- If all goes according to plan, a banana-fuelled power
plant capable of powering 500 homes could be built.
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- Mountains of waste
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- Engineering lecturer Bill Clarke, from the University
of Queensland, said he hit upon the unusual idea when the Australian Banana
Growers' Council approached him, looking for ways to use a mountain of
waste fruit.
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- "In North Queensland, bananas are abundantly available
and could be a great source of renewable energy," Dr Clarke said.
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- About one third of tropical Queensland's banana crop
- which is more than 20,000 tonnes a year - never makes it into the shops.
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- Normally they are just left to rot on the ground, but
Dr Clarke says this damages the soil - and wastes a potentially useful
resource.
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- He has successfully used bananas to generate electricity
in the laboratory, and is assessing whether a power plant could be commercially
viable.
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- Dr Clarke lets the bananas decompose in sealed vats and
uses the methane from the rotting fruit to power an electricity turbine.
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- So far so good, but the real test is whether this idea
can be a commercial winner.
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- "We don't know yet whether bananas are a cost-effective
energy source," said Dr Clarke. "So my research parameters are
designed to discover how long it will take to convert the bananas to methane,
and how much methane is produced."
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- His work involves mashing, pulping and shredding waste
bananas to find the most efficient way to make them decompose - as well
as adding enzymes to speed things up.
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- Viable energy
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- Dr Clarke says he will know by February of next year
whether bananas are a viable energy source.
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- If they are, the banana industry will consider building
a banana-fuelled power plant that could bring power to 500 homes.
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- Electricity generated at the plant would be sold to the
national grid, providing banana growers with an additional source of income.
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- However Dr Clarke admits this technology has a flaw:
it takes an awful lot of bananas to generate a small amount of power.
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- He said: "60kg of bananas are needed to power a
household appliance such as a fan heater for 30 hours."
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- © BBC MMIV http://news.bbc.co.uk/1/hi/sci/tech/3604666.stm
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