Bananas provide food, wine and beer - and now maybe fuel as well
By Matt McGrath
Science reporter, BBC World Service
You've heard of "green" fuel. Now get ready
for yellow as scientists have found a way to turn banana waste into a sustainable
fuel source that could be relevant to many countries across Africa.
Rotting banana skins are mashed into a pulp, then mixed with saw
The simple, low-tech idea, was developed by
researchers at Nottingham University.
They used banana skins to create briquettes
that can be burned for cooking, lighting and heating.
It could alleviate the burden of gathering
firewood, the dominant energy source in many parts of the continent.
This would help reduce deforestation, which
makes a significant contribution to global climate change.
In some African countries, like Rwanda, bananas
are an important and versatile crop, used for food, wine and beer.
But experts estimate that the edible fruit
makes up just a small part of what the plant produces.
"The banana skins bind other materials
together really well, they act like glue" (Joel Chaney, Nottingham
According to scientists, for every one tonne
of bananas, there are an estimated ten tonnes of waste, made up of skins,
leaves and stems.
It was on a visit to Rwanda that Joel Chaney,
a PhD student from the University of Nottingham came up with the idea of
developing a low-tech approach to turn this banana waste into an efficient
Back in the laboratory at the University's
faculty of engineering, Joel showed me how to make bananas burn.
He first mashes a pile of rotting skins and
leaves. This pulp is then mixed with saw dust, compressed and dried to
create briquettes that ignite readily and throw out a steady heat, ideal
The banana mixture dries into briquettes which can be burned on
"We can then either form the material into
a ball by hand, or use a press to squeeze the materials together and squeeze
the liquid out.
"Once we've pressed them we can lay the
briquettes outside in the sun, and within about two weeks we have some
The emphasis of the project has been on developing
a simple technology that can be used in developing countries without the
need for a large financial outlay.
Over the years there have been many attempts
to develop new stoves and fuel sources in Africa that have failed because
they were too expensive or did not take on board local needs.
"These briquettes are made by hand, we
haven't used any mechanical equipment at all" (Mike Clifford, Nottingham
Mike Clifford is associate professor in the
department of engineering at Nottingham. Standing around a stove in the
laboratory that's using banana briquettes to boil water, he says he is
really pleased with the project.
"This is working really well. These briquettes
we've made by hand, we haven't used any mechanical equipment at all. No
technology and we've had a really good result," he says.
"We're starting from very basic problems
and we are making the solutions as simple and accessible as possible to
the people that need them.
"It's almost seen as a new colonialism,
imposing solutions on people in developing countries, we are very keen
not to do that."
The scientists believe that banana fuel might
help reduce dependence on wood as an energy source across Africa.
The briquettes are easily made, no machinery is required
In some of the continent's biggest banana-producing
countries like Rwanda, Tanzania and Burundi, more than 80% of current energy
needs are met from burning wood.
This has a very damaging impact on the environment
leading to deforestation which contributes to climate change. Gathering
wood for fuel is also a time consuming job, mainly done by women.
"In some areas wood fuel is getting depleted
and you are getting deforestation. Women sometimes have to walk over six
hours a day to get firewood," says Joel Chaney.
"This is a way to use waste from crops
like bananas, to make them burn in a better way because loose residue most
often just burns too rapidly.
"Imagine just putting some straw onto your
fire at home. It just goes up in flames, you can't cook food over it, while
the briquettes provide a way to cook food in a much better way."
The Nottingham researchers say their low-tech
approach is a small step along the way of meeting the millennium goals
and helping people out of poverty.
They say that they are happy to give the idea
away for free and are encouraging people who want to use the idea to get