Cars fuelled by the land

Cars fuelled by the land

September 23, 2016

Cars fuelled by the land

One of the paradoxes of the modern world is the exploitation of agricultural land to produce fuel instead of food, with an energy yield which is frequently unsustainable.

The search for solutions based on approaches which use less energy and take better advantage of our knowledge will become one of the decisive aspects of sustainability in the field of eco-agro-food systems. The energy intensity of conventional agriculture using fossil fuel sources is significant, and the use of agriculture to produce energy is the third paradox of the food system put forward by BCFN, with increasingly fierce competition for land to use for the production of energy and food, caused by the growing popularity of using crops to produce biofuels. The idea of using agricultural land to put fuel in cars rather than food in the mouths of hungry people seems to be completely illogical in terms of equality, ethics, sustainability and simple common sense”. These are the views of environmental economist, Pavan Sukhdev, consultant for, among other bodies, the United Nations and, for three years, from 2009 to 2011, Director of the Global Agenda Council on Ecosystems and Biodiversity of the World Economic Forum.

What are biofuels?
Biofuels are rapidly produced using the biological processes of agriculture or anaerobic digestion, which sets them apart from fossil fuels like coal and oil, created from prehistoric biological material by extremely slow geological processes. Biofuels can be directly derived from plants (for instance, from rapeseed, sugar cane, maize or beet) or indirectly from the waste of various agricultural or industrial processes, as well as from organic waste. The main biofuels are bioethanol, biomethanol, biodimethylether, biohydrogen and biogas.
All biofuels are now being put under the spotlight, not just because their production means that there is less agricultural land for food production, but also because some research has thrown doubt over their general sustainability. Indeed, any energy source comes with a cost, equal to the energy which needs to be invested for its production: in the case of oil, for instance, this is the energy required to find it, extract it and transform it into petrol or diesel. For bioethanol obtained from sugar cane, this is the energy needed to grow the crop, harvest it, transport it to the processing plant and ferment it to obtain alcohol, which can then be used, as is the case in Brazil, for example, to fuel cars.

A complex measurement
A tool used to assess whether a biofuel offers a real benefit is the so-called EROEI coefficient (which stands for Energy Return On Energy Invested). In theory, it is a relatively easy value to calculate from a mathematical point of view, since it is simply the relationship between the energy obtained and the energy expended in order to obtain it. It is immediately clear that a source of energy with an EROEI lower than 1 is unsuitable because its production consumes more energy than can be obtained from the end product, leading to a net loss rather than a gain.
The EROEI is considered to be a key indicator on which to base strategic choices in energy policy, and for striking the best balance between various energy sources. However, its practical application has already thrown up complications due to the lack of a universally accepted criterion on which to base calculations and the need to constantly update the calculation with the changes in the conditions and availability of more efficient technologies.
Although for fossil fuels the EROEI value is gradually reducing as the largest and most easily accessible reserves are depleted, in the case of some biofuels, the opposite trend is emerging. This is due, for instance, to logistic factors, where some sources of energy with a low yield may be suitable for certain locations, such as islands, which are difficult to reach with other energy sources, but also for areas where it may be challenging to get sufficient amounts of food.

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