This week, new biodiesel plants made headlines in far-flung corners of the globe: In Australia, Natural Fuels Australia Limited opened a 140-million liter biodiesel plant in the country's Northern Territory promoting the sustainable use of palm oil. In South Africa, De Beers Fuel (no relation to the diamond company) announced plans to produce 16 to 24 billion liters of biodiesel made from algae.

(Of course, few who cover alternative energy in the United States could resist the obvious post-Thanksgiving stories about biodiesel made from leftover turkey fat, but we won't get into that).

Biodiesel holds huge promise: It performs similarly to petroleum-based diesel yet comes from sustainable and renewable resources. It is biodegradable, making it extremely appealing for marine applications or other environmentally sensitive areas. Finally, Biodiesel is the only alternative fuel that successfully meets the Health Effects testing required by the US Clean Air Act.

Of the biodiesel techniques in use today, the algae-based fuel seems among the most unique and intriguing. Developed by GreenFuel Technologies in the United States, the company claims it can produce 92,000 liters of fuel from one acre of algae, compared with a mere 350 liters produced from a more typical sunflower seed farm. Better still, when retrofitted to existing fossil-fired power plants, the process captures CO2 emissions, effectively killing two birds with one stone!