Gary Duffy, BBC News 28 Jul 08;
At the busy Sao Manoel ethanol plant, three hours drive from the city of Sao Paulo, the noise from the churning machinery seems relentless.
Truckloads of sugar cane arrive from the nearby fields, some cut down by hand, some - in a sign of things to come - removed by machine.
From sugar cane fields to the garages of Brazil, doubts about biofuels in other parts of the world have not visibly slowed the process here.
Marcus Jank, president of the Sugar Cane Producers Association believes ethanol from sugar cane brings environmental and economic benefits.
"The first benefit is to reduce dependence on oil," he says.
"In our case we have replaced 50% of petrol with ethanol and also it was possible to have reduced the price of fossil fuels because of the competition with ethanol.
"We estimate that if there was not ethanol the petrol price would be 30% higher in Brazil."
Flex fuel vehicles
Ethanol's strength in Brazil has undoubtedly been helped by the development of flex fuel cars, which can run on any combination of ethanol or conventional petrol.
It is also widely available at petrol stations across the entire country and is generally the cheaper option.
The technology to make a car ready to run on flex fuel is neither complicated nor expensive - it costs just a few hundred dollars to adapt engines during the manufacturing process.
At the US automotive giant General Motors' (GM) plants in Brazil, there is no doubt that this is the future.
During the past three years, 100% of the cars rolling off the production lines here have been flex fuel, while across Brazil 90% of new cars are built the same way.
Future potential
The GM management in Brazil has enthusiastically embraced ethanol from sugar cane as an energy option.
And looking to the future, GM's president here, Jaime Ardila, says if governments and the private sector work together then emerging technology will offer answers to some of the concerns about bio fuels.
"The debate that has occurred on ethanol for good reasons - the concerns about food and food prices and so on - has clouded a much more important issue," he says.
"If governments and the private sector can jointly develop technologies to produce ethanol from sources that don't affect food and water consumption and so on and then help with distribution the world will definitely be better off."
Slave labour?
Undoubtedly, cutting sugar cane by hand in the fields is some of the toughest work imaginable, and working conditions in the industry have long been controversial. In some parts of the country it is sometimes described as akin to forced labour.
"In terms of slavery," says Braz Albertine, president of the Federation of Agricultural Workers in the State of Sao Paulo, "in Sao Paulo it is very difficult to say that here there is slavery work. In other states it has been found.
"We have already found worker' accommodation in terrible conditions, ethanol plants that delay payments or don't supply personal safety equipment.
"There are companies that work properly and others that don't."
The machines replacing the men who cut down sugar cane can already be seen in parts of the state of Sao Paulo and elsewhere.
Producers say this will help to address many concerns about working conditions.
At ethanol plants such as Sao Manoel, they say they keep within rules set by the government for rural workers, and have introduced changes to improve working practices.
Other fears have been raised by the Brazilian experience; some worry that the rapidly growing demand for ethanol will push crops and cattle further north, threatening the Amazon rainforest.
It is a concern that Marcus Jank of the sugar cane producers association is keen to reject.
"We are using 3.5 million hectares to produce sugar cane ethanol, and there are 200 million hectares of pastures in Brazil, so it is extremely small," he says.
"We believe that we are going to double the ethanol area in the next 20 years, but it will still be only 2% of arable land."
Greater access
If concerns about conditions are addressed, and land is well managed, says Professor Jose Goldemberg, of the University of Sao Paulo, ethanol from sugar cane has much to offer the developing world.
"In the next 10 years it offers a replacement of 10% of the gasoline (petrol) in the world, which is a large amount," he says.
"Today, about one trillion litres of gasoline are used in the world, and 10% of that could come from renewable fuel such as ethanol from Brazil and other tropical countries.
This, he claims would happen "without damaging food production, and without indirect effects such as damaging the Amazon forest and increasing deforestation".
To fully realise that potential Brazil and other developing countries will need greater access to world markets.
And that is exactly the kind of argument they have been putting forward as part of efforts to conclude the Doha trade talks in recent days.