Biofuels might still be environmentally and commercially correct if we make the right choices and use the most appropriate energy feedstocks, writes DICK AHLSTROM.

DUCK, QUICK, if you don't want to get wet. The biofuels baby is getting thrown out with the bathwater and, once disposed of, we are allowed to condemn it as a bad idea.

However, that baby should be rescued and rehabilitated and turned into something valuable. We need to be smart about biofuels, not just politically correct.

We used to think biofuel production - biodiesel made from oil crops such as rape and palm, and bioethanol, alcohol derived from grains and then blended with petrol - was the right-on environmental thing to do if we wanted to save the planet.

Even better, we could still feel environmentally good about ourselves by converting the 3.5-litre SUV shopping centre chariot to run on stale frying oil.

Now we hear that the biofuel industry causes more pollution than fossil fuel burning, drives up food prices by diverting land for food production into land for fuel production and is completely unsustainable over time.

The promotion of biofuels was once a favourite of green campaigners around the globe who argued that they provided a renewable alternative to non-renewable fossil fuels. The Bush administration enthusiastically latched on to this idea, holding it up as proof of the administration's green credentials - even as it refused to subscribe to the Kyoto Protocol.

Farmers in the US rushed to accommodate this new world, tempted by the higher prices paid for corn, barley and wheat to help feed the biofuel factories that quickly sprang up with government support. This saw the price of a bushel of corn double from about €1.50 in 2006 to €3 in 2007.

It took a few years for the changeover, but now we aren't supposed to like biofuel. It encourages countries to burn down rainforests to make way for sugar cane used for bioethanol and oil palms that deliver biodiesel. And a world crisis has been precipitated with rapidly rising international food prices pushed up at least in part by biofuel production.

But biofuels might still be environmentally and commercially correct if we make the right choices and use the most appropriate energy feedstocks.

We don't have to grow food crops to make renewable energy: we can grow grass. And forget your ethanol mixed with petrol, natural gas is a cleaner fuel that we can derive from household garbage, abattoir waste and even whiskey distilleries.

University College Cork's Dr Jerry Murphy has studied these things closely and has figures to prove that almost nothing can beat good old silage stewed in a digester and used to produce methane, the most natural gas that money can buy.

Just 6.5 hectares of silage used for biogas could keep a double-decker going for a year. He also found that the spent "greens", the organic leftovers from Irish Distillers' whiskey production in Cork, if sent through the digester, would keep 150 buses on the road all year.

Ah, there you go, taking arable land out of production to grow grass, the naysayer argues. Not so says Murphy. Ireland has about 4.5 million hectares of farm land, about 400,000 hectares of which is arable. Grass grows just about anywhere, including up the sides of mountains and on very poor soils, conditions unsuited to food crop production.

If you don't care for farming, then go for other high-volume organic sources, such as the massive domestic waste stream that flows out of every city and town in the State. About 40 per cent of the two million tonnes of domestic waste we produce each year is organic and suited to digester treatment. This approach reduces waste volume and landfill requirements and effectively gives us something for nothing. And notice I never even mentioned the "I" word (incinerator) as an energy source.

Then there are the sewage sludge and abattoir waste options for energy production. Slaughterhouse waste produces enough biogas to power Linkoping, Sweden's bus service, plus 600 gas-powered cars and a commuter train that runs on methane.

Lille in France keeps its urban buses chugging along on digested sewage sludge. After digestion, the resultant safe material can be used as a fertiliser.

Biofuels won't supply all the answers, but it would be foolish to eject these sources from the current mix of options. This is particularly true for Ireland where we have limited non-native supplies of fossil fuels. We must have energy security, which means it is essential that we apply renewable sources such as biofuels, wind, wave and hydro.

We are at the end of the European gas grid which makes it easier for us to get switched off. If we don't exploit the renewables available to us then we might have to reconsider our loathing of nuclear.