It's most well-known for being the main ingredient in the production of the Mexican spirit tequila, but a drought-resistant succulent plant is being touted as the next generation in biofuels. Central Americans have used the sap of the agave plant to distill their potent brew for centuries, but an Australian company wants to harness its high sugar content to make ethanol for energy.
Sugar cane is already used in Australia to make sugar for ethanol production, especially in Queensland where there is a long-established cane industry and 10 per cent ethanol petrol is widespread. Proponents of agave say they are not trying to replace sugar cane as a source of ethanol, but their plant is an ideal fit for climates where cane does not flourish.
Australian company Ausagave says it has 10,000 agave plants in pots that are ready to be trial planted. Ausagave's Don Chambers says he has been researching the cultivation of agave for the past four years, and he believes crops could produce between 10,000 and 16,000 liters of ethanol per hectare per annum.
His forecasts project an estimated cost of less than 40 cents per litre. This compares with 34c/L for molasses and 44c/L for sugar cane. He says sugar cane averages a yield of 9,500L per hectare per annum. Mr Chambers says the plant is tough enough to survive temperatures of up to 50 degrees Celsius, making it ideal for Australia.
"It can grow basically in the desert," he said.
" We've been doing trials here in South Australia, and it doesn't die without water, it can withstand extremes of temperature, it wouldn't be as subject to storms like some of the crops like cane are.
"If you compare it with [sugar] cane and corn, it does have less operational costs and it can grow in very marginal land."
Cool of the night
Agave is a CAM plant, meaning the pores on its leaves open at night rather than during the day. This means it retains a lot more water than plants that grow during the day.
"It's one of the most water-efficient plants in the world," Mr Chambers said.
"It's very robust and very resilient, in fact the place I've got it growing in South Australia is one of the coldest places in the state and yet we've got some in some of the hottest places and it's still surviving."
The resilience of agave is its main selling point for use in Australia. Supporters say its performance in marginal soils and dry conditions means it could add to the biofuel sector without displacing existing crops. Because agave is not used as a food crop, it would not have to displace any existing food or biofuel crops, says Professor Nanjappa Ashwath from Central Queensland University.
"It doesn't compete with the other sources of biofuel, such as sorghum or soy beans, which are also used as food crops," he said.
Professor Ashwath says Australia provides a perfect setting for agave production, because of the large areas and harsh climatic conditions.
"I just came back from a three-month trip to India and Rajasthan and they have very large dry zones and agave is being grown there in Rajasthan and they've got a lot of other places where agave can grow well," he said.
"Sugar cane is really suited to high-rainfall regions and the coastal areas and we are talking about the drier zones where we don't have much irrigation.
"For example the mining lands and some of the lower-lying areas where we can plant and get the bio-ethanol."
Qld furthest advanced
Mr Chambers says he has approached the Queensland Department if Primary Industries (DPI) and Townsville's James Cook University about finding a place to start trial planting.
"We've got a lot of interest and support from Queensland. Putting it all in perspective, there's no use growing it where there's no support from government with mandated fuels.
"If you look at the supply chain, you've got to have demand for it, so it's got to go into the fuel and to go into the fuel you've got to have processing facilities and you need crops,
"Queensland is the furthest advanced in this area with the sugar already having a capacity to produce ethanol."
Professor Ashwath sees the logic in the choice of Queensland. He says biofuels are an important part of sustainable power generation, and government policies are essential to growing the industry.
"Any new initiative needs an input from the government because there are so many unknowns," he said.
"What type of agave can we use and what are the cultivation practices? How do we harvest and what kind of plant, who's going to provide the raw materials to the industry?
"The Government needs to be involved because otherwise it would not be viable to start with."
Source: ABC News