The Biofuels Controversy

Shell caused a stir the other day, when they announced their withdrawal from all their wind and solar projects, in favour of biofuels. This could be good for Australia, according to some including the former Chief Scientist, Robin Batterham (here writing as President of the Australian Acadamy of Science and Engineering). But are biofuels good for the Earth?

Biofuels can be loosely defined (thanks Wiki) as any fuel sourced from "recently dead biological material". Their main attraction for energy solutions is that, unlike most renewable sources, they can directly replace petroleum products, as liquids with similar energy density, and are thus able to power (regular combustion engine) vehicles and even aircraft.

This is makes them important even in the absence of any greenhouse gas emission considerations: Arguably, Peak Oil and the emerging "energy gap" are problems just as serious as, and even more acute than, climate change.

However, in principle, biofuels can also be carbon neutral, since any carbon released by burning them is carbon that was removed, from the atmosphere, by the plant that produced the fuel. The "in principle" qualification is important however, since soils also contain a large amount of adsorbed CO2, some of which may be released when the soil is tilled. In addition, energy use during production – making fertilizers, preparing and irrigating the land, harvesting the crop, etc – must also be taken into account.

The controversy arises when you consider the sustainability of biofuels from an agricultural perspective. From land clearing to make way for sugar in Brazil (who already run a large part of their transportation on ethanol or ethanol-rich petrol mixtures) to as yet unanswered questions regarding the contribution of biofuels to the recent massive increases in world food prices. Even environmental groups are divided, and nobody seems quite to be certain what to do.

There are many possible causes of rising food prices. It is difficult to be sure which reasons are mot important, and it is premature to blame biofuels. Nevertheless, guilty or innocent this time, the economics is simple in the medium to long term. The world's thirst for oil ensures it will become a serious problem, when farmers especially in poorer countries can do better selling fuel than food.

These concerns relate mostly to what can be called 'first generation' biofuels: ethanol fermented from sugar cane or other sugary or starchy crops (corn in the USA is another big one). Ultimately they suffer from a problem of scale, in that there is just not enough arable land for fuel from these crops make a serious dent in fossil fuels oil and gas emissions, even ignoring the competing need to grow food on it.

Fortunately, second and later generation biofuels offer likely solutions. Feedstock can be sourced from waste biomass, as a Finnish company (there may also be others) is already doing, to produce ethanol. This is more a recycling effort of sorts, but very important especially because if allowed instead to decompose as landfill, biowaste can form methane, that pesky bovine-burp of a greenhouse gas that happens to be more than 20 times more efficient at trapping heat than CO2.

The first commercial ethanol plants that use cellulosic material (see also a press release here) are already operating in the USA. These are currently operating mainly on woodchips, however scientists are working on genetically modified grasses and the like which can be grown on very poor land with high yield, and used in a similar manner.

The holy grail of biofuels is algae, although it is as yet uncertain how soon this can become a commercially viable route. The CSIRO have a dedicated centre working on oil-producing algae, and they are by no means the only ones in the game. Algae can be grown in tanks that can be built anywhere a water supply is available. Some algae can grow in salt water, although this is yet to be perfected for the oil-producing species. If it can be, the potential area available for exploitation of course becomes effectively infinite. Algae it seems can also be found that produce hydrogen – another interesting development worth watching. Last but not least, contaminated water such as sewage or agricultural runoff can be beneficial to algal growth, opening possibilities for solving several problems at once.

It seems to me that we can hope that the food-for-fuel problem can soon be circumvented, and sustainable expansion of the biofuels industry achieved. Plenty of political care is still required however. The availability of these second-generation solutions don't guarantee the cessation of exploitation of first generation methods! One can be sure that until the new technologies make ethanol (for example) cheaper than the food crops do, we or our trusted governments will probably need to pay a 'free range eggs' premium to ensure our biofuels are the good kind. Make sure you keep watching.

Change 2 contributor Dr Miles Page is an Australian scientist who has been working at the international coalface of the emerging Energy Revolution. After receiving his PhD from Sydney University, Dr Page held senior research positions with the Atomic Energy Commission in Paris and the Max Planck Institute in Potsdam. He has spent the past 3 years in Israel researching Thin Film Solar Cells at the Weizmann Institute of Science and developing alternative Fuel Cells.