Yesterday, Amex listed O2 Diesel closed down 8.3%. The company aims to break into the US diesel market, which powers 94% of US freight, with an optimal blend of ethanol and mineral diesel. These additionally tuned oxygenates will remove many of the harmful pollutants that typically come from diesel.

Many parts of America such as California have demanding air quality standards which ought to encourage the take up of 02 Diesel.

But it's a tall order to design and implement a complete supply and refuelling programme. They are however exploring the military market and there's plenty of political support for the growing use of ethanol in America.

Definitely one to watch . . .

Despite her big movie combacks in the Kill Bill films, Daryl Hannah has revealed that saving the planet is more important to her than making movies. Not only does she have a solar-powered home, she drives a 100% biodiesel car.

Biodiesel is a lean burning alternative diesel-like fuel produced from energy crops which produce vegetable oil, tallow or cooking oils. Diesel fuel for passenger cars is virtually non-existant in America and biodiesel, even less, so this is very unusual. Diesel exists in the USA to power freight transport. And one listed company, O2diesel, hopes to turn a significant portion of that into biodiesel. Their target market is refueling for bus, trucks and off-road fleets.

So where does Daryl Hannah get her biodiesel from?

The American Midwest has made money out of farming hogs / swine the 19th Century, leading to the creation of the first modern futures markets. Now there's a new angle, trading the Greenhouse Gas Emissions that come from Pig Manure. And Agcert, a leading Bioenergy Company listed on London's Aim shows the way. Since going public in June, the stock price has risen from 140p to 230p today, valuing the company at around $500 million.

In an interview with yesterday's Sunday Telegraph, Al Tank, Agcert's CEO, described as "a compact farm boy from Iowa with an unnerving knowledge of pigs . . . and a crisp, clean, white collar", set forth his vision. Amongst several salient points, there was even a China Story - "Half the world's pigs are in China, which is a unique opportunity," says Tank.

What's particularly interesting here is that 20% of world GHG emissions are from Agriculture. Why?

Because methane - from farm animal manure - is a 20 times more powerful GHG than Carbon Dioxide. Moreover, captured methane can be burnt to provide heat and electricity, whereas CO2 can only be sequestrated at considerable cost.

So there you go. Now you know the true value of methane.

Having gone public last year in June 2004, UK Aim-listed Biofuels Corporation has struggled since April due to delays in bringing production on line. The company is building biodiesel processing plants.

Yesterday however, the stock had a great day yesterday surging 39 to 184p after the biodiesel group confirmed its Teesside plant is on schedule. The group said it has sold 64pc of start-up production and has a strong lists of leads in respect of a further 25,000 tonnes per month - more than three times the 7,500 tonnes per month remaining to match full production.

This is important because the company could now be judged to have sufficient sales contracts to commence full production at its new Teesside plant on schedule by the end of September.

Biodiesel in Europe seems poised for expansion due to non-binding EU targets of 20% blend of biofuels into petroleum fuels by 2020.