The sea, by contrast, is both free and self-maintaining.Mr Munford reckons an area the size of the North Sea could yield enough biodiesel to replace the fossil fuels used in transport today.
There is plenty available: according to a report by the United States Department of Agriculture, more than 7m tonnes of coffee are consumed every year, which the researchers estimate could produce some 340m gallons of biodiesel.
When cooled to room temperature and left to stand, the biodiesel floats up, leaving a layer of glycerine at the bottom.
And it, too, has hooked up with an oil company: Total, of France, which owns 17% of the firm.Amyris's biodiesel is made of more complicated molecules than Codexis's (they are known, technically, as terpenes), and the firm employs genetically engineered yeast, rather than bacteria.
But now it, too, has a product that it claims is a drop-in biodiesel.
He favours tax breaks for biodiesel, which would "stop the Saudis from playing the jukebox and the rest of us dancing to the tune".
BRIAN SCHWEITZER, Montana's Democratic governor, proudly shows off the knick-knacks in his office: bottles of Montana biodiesel from old restaurant cooking oil, a lump of coal, a model car that runs on a hydrogen fuel cell.
The federal Renewable Fuel Standard, passed in 2005 and updated in 2007, requires that by 2022 refiners blend 36 billion gallons of renewable fuel such as ethanol and biodiesel into motor fuel.
Although biodiesel is (before tax, at any rate) more costly than traditional, petroleum-based fuel, it does have environmental advantages.
A machine called the Tactical Garbage to Energy Refinery (TGER), heats solid waste to produce syngas (synthetic gas, a mixture of carbon monoxide and hydrogen), ferments food slops to produce alcohol, and chemically processes the two to make biodiesel that powers a generator.
Elsewhere, there is even talk of producing biodiesel from pig manure.A few hiccups have curbed the enthusiasm.
