A growing number of Americans are setting up mini-refineries in their homes
to produce biodiesel, a fuel made from waste cooking oil which is cleaner and
cheaper than the petrol sold in gas stations.
The sky-high price of crude oil is scaring everyone.
Biodiesel has Hollywood backers like actress Julia Roberts and Morgan
Freeman, is sung about by country star Willie Nelson but also meets the
political correctness of the American right wing which has made the campaign
against imported oil a mantra.
"It's better for the engine, way better for the environment, it's cheaper,
but it depends how you price your labour," said Dan Goodman, an entrepreneur in
residence at the University of Maryland Business School who runs his Mercedes on
There are two ways to get on the biodiesel bandwagon, Goodman said. Either
you change the engine and just put in waste oil, which would not be strictly
legal in the United States, or you can modify the fuel into biodiesel, which is
legal and works in any diesel car.
Biodiesel plants are a boom industry in America, but thousands now make fuel
in their garages from the oil left after frying french fries or scrounging
around restaurants and food factories.
"It's easy when you know how to do it," Goodman said, though he warned that
the process "can be hazardous," since it involves flammable products and caustic
vapours that require a well-ventilated production site.
"You filter the waste fried oil to remove the glycerol, the most sticky part,
and then replace it with an alcohol molecule (methanol) and lye (caustic soda),"
Goodman makes about 300 gallons (1,135 litres) of biodiesel a day on a farm
in Maryland, where his helper Matt Geiger twice a week brings huge jerricans of
the precious "yellow grease" he collects from restaurants in the towns of Olney
and College Park. The homemade fuel keeps 15 school buses running in the area,
Most biodiesel fans have organized into co-operatives
that make biofuel from soy oil instead of used cooking oil. The groups have been
growing over the past few years, but they still represent a minuscule part of
the US energy sector.