Biodiesel

Biodiesel is an alternative fuel made from renewable resources such as vegetable and grain oils, tallow and lard. In some countries it is commonly blended with diesel at concentrations of up to 20 percent (B20).

In theory it should be possible to operate diesel engines on straight biodiesel, however to date there has been little proper scientific testing of straight biodiesel under Australian conditions. Concentrations above about B20 are likely to adversely affect cold weather starting and performance.

Few manufacturers of vehicles sold on the Australian market currently accept the use of more than B5, while others recommend against the use of any level of biodiesel. Vehicle owners should therefore check the recommendations of the vehicle manufacturer before using biodiesel, particularly if the vehicle is covered by a new vehicle warranty.

Overseas experience suggests that high concentrations of biodiesel may react with, and soften, certain types of rubber fuel system components and care is needed to ensure that fuel hoses and fuel pump seals are of a material that is not susceptible to damage. As biodiesel contains no aromatics, older and degraded fuel pump seals may begin to leak when exposed to higher concentrations.

Biodiesel can be made at home from used cooking oil. The process uses potentially dangerous chemicals and is likely to be unacceptable to local authorities, emergency services and insurers. Incorrectly manufactured biodiesel can cause corrosion, fuel system blockage, seal failures, filter clogging and deposits at injection pumps.

All biodiesel, including that manufactured at home for personal consumption, is subject to excise duty of 38.143 cents per litre. This can be claimed back under the government's Cleaner Fuels Grant.  However, the fuel must meet the standard defined by the Fuel Quality Standards Act 2000. It is likely that the cost of certifying that homemade biodiesel meets the Fuel Quality Standards Act 2000 would be prohibitive for the average home producer.

Biodiesel is only likely to be a niche fuel because there would not be sufficient feedstock available to convert all of Australias diesel fuel usage to it.