Biofuels

You’ve probably heard about biofuels and you probably have an opinion on them. Biofuels shot to public prominence when they were vaunted as the saviour, the silver bullet that would allow us all to continue using cars, trains, planes, boats, vans and trucks but without contributing to human induced climate change. Within a staggeringly short space of time they turned in to public enemy number one, single-handedly pushing up food prices, leading to mass food shortages, breaking our cars and actually increasing greenhouse gas emissions.

Unsurprisingly neither of these scenarios is wholly accurate. So what is the truth about biofuels?

To understand why biofuels have been so greatly misrepresented by both sides of the argument we need to understand one thing. Biofuels are a massive topic and are therefore really complicated and really complicated things are very hard to report in a digestible way in the mainstream press so they get simplified. And when they get simplified they get polarised.

Why are biofuels so complicated?

The first thing to establish is that unlike petrol and diesel, “biofuels” covers a number of fuels and they can be made in a number of different ways. For example the following are lists of biofuels, feedstocks (what they are made from) and processes. These lists are far from exhaustive but illustrate the issue.

These are all biofuels:
Biodiesel, Syndiesel, DME (gaseous), Methanol, Ethanol, Biobutanol, Biomethane (gaseous) etc

And these can be made from:
Rapeseed oil, sunflower oil, waste cooking oil, tallow, wheat, sugar beat, straw, waste wood, farmed wood, organic waste, sewage, manure, algae, jatropha etc

Using these processes:
Esterification, hydrolysis and fermentation, gasification, anaerobic digestion, algae harvesting etc

With such a range of fuels, feedstocks and processes it is important not to make sweeping statements. Some combinations of feedstocks, processes and resulting fuel result in net disbenefits whilst some result in net benefits. This is how “biofuels” can simultaneously be good and bad. It is important to be clear about which fuels, processes and feedstocks we are talking about when we talk about benefits and disbenefits.

What are we comparing biofuels to?

When thinking about the effects of biofuels, both positive and negative, it is important to be clear what we are comparing them to. The greenhouse gas emissions and wider environmental impacts of petrol and diesel are often regarded as fixed points. Most of the oil that has been extracted so far is relatively easy to get to (conventional reserves). In the future we are going to have to exploit more of the unconventional reserves such as oil shales and tar sands which require far greater energy inputs. This will result in the carbon intensity of petrol and diesel increasing assuming that there is no mitigation. The extraction and processing of oil shales and tar sands can also be water intensive and has significant social and economic impacts on local communities.

The conventional fuels industry and the biofuels industry should be viewed together, as production outputs from each will affect the other. The development of biofuels may reduce the need for more unconventional reserves to be used, effectively providing a double benefit. Just as the biofuel industry must develop with the tightest of sustainability and greenhouse gas standards so must the conventional industry if both are to contribute to providing our energy needs at the minimum environmental cost.