Saturday, 11 October 2014

Biomess? – fuel for thought

By Dr Dan van der Horst, University of Edinburgh. This article first appeared in the summer 2014 edition of the RSGS's magazine, The Geographer.

Making and controlling fire was perhaps the single most important invention that allowed humans to conquer the planet; keeping us warm and safe, improving our food, and transforming our landscapes. Even today, biomass energy is the most important source of energy in many developing countries. But the production of liquid biofuels, a policy pursued by the EU and the US, is highly controversial with environmental, social and conservation NGOs, even if most people in Scotland have no idea it is in their fuel tanks. In this short piece I will not revisit the extensive debate of how biofuels impact on food production and biodiversity, and what it would take to reduce or control these effects. Instead, I focus on a few home truths about biofuels that have received less attention to date.

The economic problem of biofuels is that they are, under most conditions, a relatively expensive way to reduce carbon emissions, so public money could be better spent on other low-carbon interventions. Whilst other renewables may experience technological breakthroughs or significant price reductions due to mass production, this is far less likely to happen for biofuels as they are based on a feedstock that has to be grown on land, which comes with an opportunity cost.

First generation biofuels (ethanol made from starchy or sugary crops, or biodiesel made from plant oil) are only a good value product in a market where food prices are low and petrol and diesel prices are high. Unless food production is subsidised and fossil fuels are taxed, these are rare conditions. In the absence of subsidies, we can perhaps envisage such conditions in a very remote corner of Africa where people can produce a surplus of food but cannot export it due to very poor transport links, which in turn also make the import of diesel and petrol very expensive.

Biofuels could have a useful role to play in an oil-importing developing country that is selfsufficient in food production but is struggling to sell its agricultural exports on the world market, for example because of logistical bottlenecks or import tariffs. Under these conditions, biofuel production could be a useful way to enhance the trade balance (spend less hard currency on importing oil) and boost the rural economy instead. This is how Brazil came to adopt their sugar-to-ethanol programme.

The carbon problem of second generation biofuels (made from inedible, woody biomass) is that there are better uses of the feedstock: using biomass as building material will store carbon for decades or longer. And when the time comes to dispose of these materials, they can still be burned for energy recovery. If there is a suitable place for biofuels in an industrial country, then it is first and foremost in integrated waste management. In the first decade of the 21st century, the UK was producing more renewable energy from biomass than from wind. This was not because we have big agricultural or forestry sectors, but because we were implementing the EU waste directive, which told us to cap landfill sites and capture the methane that emerges from them. Some of the largest anaerobic digestion plants in Europe are now found in the West Midlands; modern centralised facilities for treating sewer sludge and food waste. It could even be argued that we would have no need for a separate energy policy, if our other policy domains, such as foreign policy, environmental policy and economic policy, were more coherent and integrated.

At the end of the day, there is one very simple fundamental problem for biofuels. If you want to extract the highest possible value from a product, that product has to be very cheap and plentiful to ensure that putting it on fire is the best option. Smoking (whatever...) is just the exception that proves the rule.