That story paints a rather limited view of what's possible regarding
biodiesel. There are many more productive 'crops' like algae for biodiesel.
Yields of 1000 gallons per acre are possible.

What's needed is an awareness of how much WASTE we, the US population, are
responsible for. If everyone used half the fuel (or less) we would likely
not have to concern ourselves so much with this subject. I'm doing my part
best I can...I used approximately 130 gallons in my car in the past year,
about 50 percent of that was commercially refined recycled-fryer oil
biodiesel. I'd like to decrease that usage figure even further.

>While recycling fryer oil from the local fast food might be "green,"
>large scale biodiesel (or ethanol) production is not.
>http://www.scienceblog.com/cms/node/8353