Mar 2006

Biofuels – The fuel of the future

Biofuels are the fuel of the future claims the Green Party of Ireland. Let’s hope they’re wrong.

I was heartened to see that the Greens are an influential force in Irish politics. While the latest polls suggest they’ll only get 7% of the vote in the next General Election (probably next year, though theoretically it could be called early), Ireland’s proportional representation system means that they could very well – given current party alliances – find themselves holding the balance of power. Whichever of the major blocs wishes to form a government for the next five years will have to offer the Greens something significant in order to do so. A genuine bidding war between the two major centrist parties over who can offer the most environmentally sound policies would be nice to see.

Hardly revolutionary I grant you. But it’s a step in the right direction.

I just hope the Greens don’t squander the opportunity by demanding support for the biofuels strategy. Environmental organisations in Ireland, and throughout the world, need to be attacking private car use as the absurd and obscene waste of resources that it is. What they shouldn’t be doing is reassuring people that the future can be business as usual, just by different means. It may be a less popular message, but it has the advantage of being the truth.

Though perhaps it’s foolish to believe that should count for anything.

According to Nationmaster (a godsend for those of us who habitually like to pepper our writing with statistics) who cite a 2002 World Bank report, Ireland comes 18th in a survey of car-ownership in developed nations. There are 272 cars per 1,000 people in Ireland which is significantly below the developed nation average of 437.3 per 1,000.

However 272 cars per 1,000 people still amounts to almost 1.1 million cars in a nation of 4 million people. And it’s a pretty small island.

Now, if we are to believe the RAC, the average distance travelled per car per annum in Ireland is 16,000km, with an average engine efficiency of 10.55km per litre. So Ireland’s private automobile fleet gets through – back of the napkin calculation – 1,650,000,000 litres of petrol per year. 1.65 billion litres. Which is a lot of fuel for a pretty small island. And that’s private automobiles (Ireland has 359 motor vehicles per 1,000 people; I’m concentrating only on cars here).

How many litres of biofuels would be required to replace 1.65 billion litres of petrol? And how much arable land would be required to grow all that biomass? Have the Green Party worked out these numbers? I suspect not. Certainly they don’t publish them on their rose-tinted website. And where do the Greens stand on the subject of biodiversity Vs monocultures? Championing biofuels would suggest a side of the fence I’m not comfortable on.

Plus, rather importantly, the ERoEI of biofuels isn’t well-established. There’s been few studies, and fewer still large-scale experiments. David Pimentel (a professor at Cornell) published a study in the Encyclopedia of Physical Sciences and Technology (a peer-reviewed journal) which created significant controversy by claiming that ethanol from corn (one of the most widespread biofuels) has an ERoEI of less than 100%. In other words, claims Pimentel, the planting, harvesting and conversion of corn into ethanol uses more energy than gets generated by burning the end product.

Note: Energy Returned on Energy Invested (ERoEI) is sometimes referred to as Net Energy Ratio (NER). Although the two have slightly different definitions, with one being expressed as a percentage, the other as a decimal ratio; they are nonetheless similar enough to consider them the same thing in all but the most technical of discussions. I’m pointing this out because I’ve noticed both terms beginning to crop up in the mainstream media for the first time, and I figured some of you might want to know that they’re near-as-dammit interchangeable (though I’ve encountered pedantic scientists who fly into quite colourful rages for suggesting such a thing).

Anyways, quite apart from Pimentel’s study – which is still causing some consternation and throws the averages right out the window – I’ve read a few papers on the subject, and even contributed my number-crunching skills to one of them. It wouldn’t be out of order to suggest that ethanol can be generated with an NER of between 1.38:1 and 2.62:1. Plus the US government has a new study underway which it believes will give a return of 5:1 (though it concedes in that case “much of the energy gain comes from generating electricity by burning the co-product lignin, rather than from the ethanol itself”, so it should be discounted as a great leap forward in liquid fuel production).

But let’s say we pretend to be optimists for a moment and take that 2.62 and roll it in a little bit of the US government’s 5.0. Let’s say, given optimum conditions and efficiency, you can regain 3.5 units of energy from ethanol for each unit you input into growing and producing it. That’s still a long way off crude oil’s 40:1 to 100:1 (depending on the well). So far off that I’d hesitate to suggest one as a substitute for the other even without calculating the arable land required. You just know it’s not going to be good, right?

Pimentel’s study suggested that 97% of all of America’s arable land would be required to fuel the private automobile fleet of that country (again leaving aside freight, air travel, military and government usage, etc etc). And while America has a lot of cars… it’s also got a lot of arable land. What would it be like for Ireland?

Well, if you were to do a genuine like-for-like comparison, and insist that the biofuel industry pay for itself energy-wise in the same way as the fossil fuel industry does, then we should scale up the number of litres of fuel required by the same amount as the NER is scaled down, even though the energy contained in the ethanol isn’t necessarily quite that much less than that contained in petrol. In which case, let’s use the government 5:1 (as we can assume that the electricity generated by the co-product can be channelled into biofuel production in some way).

So using the optimistic biofuel NER of 5:1 and the most pessimistic crude oil NER of 40:1, it suggests that Ireland would require the production of 13.2 billion litres of bioethanol to fuel the current private automobile fleet. I’ll also use the most optimistic litres per hectare number I can find (an Indian company, Ammana Bio, has claimed 7,000 litres per hectare from sorghum; far more than the 1,500 litres / hectare that is often quoted when discussing UK / Northern Europe biofuel production) in order to get a highly conservative estimate of 1.88 million hectares.

Again using Nationmaster we discover that Ireland has a total of 1.05 million hectares of arable and permanent cropland. This suggests that if Ireland were to make the transition to biofuels without a significant parallel reduction in car usage, we’d need to dedicate the entire arable surface of the nation to growing high-yield stock for bioethanol, and still import 45% of our fuel. Quite how this squares with the Green Party’s insistence that “the poverty of two-thirds of the world’s family demands a redistribution of the world’s resources” is anyone’s guess.

Let’s stop talking about biofuels. Start talking about fewer cars.

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