Do we have enough food energy?

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Do we have enough food energy?

“Energy is neither created nor destroyed, it only transforms” according to the First Principle of thermodynamics. Physicists announce us, and daily experience confirms it, that energies are interchangeable in their forms and their units of measure have their equivalences, we pass from Kwatts to KJulios and Kcal, and vice versa, as measures of the same concept, energy. But is it true?


Imagine the universe (exclude the earth). There is an enormous amount of nuclear, fossil, solar, electromagnetic, gravitational energy … But there is no life (possible but very improbable) known. And life, our existence, needs the energy it receives in the form of the contribution of food energy. If it did not exist, the other energies would continue to exist, but the writer and his esteemed readers would not exist. We need to feed ourselves to live, and we get the energy of food from photosynthesis.

To create food energy we have to start from solar energy (obtained from any of the other forms) and transform it from the biological system of photosynthesis, which is the factory producing the products that provide energy to heterotrophs. This is the only way and the inverse is possible: products with food energy for man can become another form of energy.

Faced with the challenges we face (climate change, increases in population, increase in food production, decrease in available resources: water, land …), concern for the environment has become part of our lives, we have to do more with less and all this in a sustainability environment that guarantees the future of the new generations. So converting food energy, of specific use for food, into physical energy for general use (such as biofuels), can be potentially conflictive because it affects the social and political stability depending on the process. Bridging the issue, humanity needs two types of energy: the essential to maintain life, that is, the energy in the form of food the origin of which is in photosynthesis (as the very system of life to capture and transform physical energy to their needs), and what we could call energy of development, that of human achievements, of its economy, its technologies, its services, transport … and this second is valid any physical energy independent of its origin (nuclear, hydraulic, fuel / gas, coal, renewable …).

On the other hand, in today’s society the average consumption of energy per inhabitant of the planet is estimated at 200 MegaJoules / day, of which only 4.2% (8,400KJ / day) corresponds to the need for food energy. It is evident that in the total energy consumption, the weight of the specific food energy is small, very small, but essential. Therefore, we must not forget to work for maximum efficiency and sustainability, since it is a weak system, the efficiency of the conversion of solar energy (photovoltaic) into food product does not reach 3% in the best of cases and the earth cultivable, with its needs for fresh water, is today 3.9% of the total land area. It is necessary to avoid that these relatively scarce resources depart from the alimentary system in their fundamental mission of maintaining and developing life. The sustainability of food production must be maintained but without damaging its mission. A balance must be struck between the availability of food and the use of food energy to produce physical energy. Thus, the contribution of total energy consumption of food energy is small (less than 5%) but essential for life.

Today this balance has been displaced, an example, USA uses 40% of its corn (food energy) to produce biofuels (physical energy) and this has caused a significant increase in the cost of food based on this cereal (in Mexico by example).

The society begins to become aware and research on the development of biofuels, called 2nd, 3rd and 4th generation, is already underway. The vegetable structure (agricultural residues) is used, without nutritional value, which is discarded. The subject is of complex investigation since to hydrolyze efficiently cellulose to glucose (so that it is fermentable to alcohol) is not technically or economically easy. Other routes are under study, specific cultivation of algae, cultivation of non-food vegetable species, but in this case there may be conflict with water and soil resources, fourth-generation biofuels with carbon storage.

In short, a challenge for research, innovation and economy under the overall responsibility of the Society (government policies and companies) in order to achieve maximum energy efficiency, without unsustainable damage to the environment and without negative effects on the accessibility of all citizen to their food, accessibility affected by multiple social factors among which the availability / price ratio is critical.

The analysis was impact of energy and the environment on the competitiveness of the food sector, in a seminar organized by the Gas Natural Fenosa Foundation on June 16 in Logroño. The seminar was inaugurated by representatives of the Government of La Rioja, a very dynamic community in agrifood production and counted with the participation of several experts, who analyzed the subject from different perspectives.

By Yvonne Colomer | Director Triptolemos Foundation 

Triptolemos Foundation for agri-food development since 2002 collaborates in the optimization and articulation of the functioning of the food system, so that it results in greater availability and quality of food, in confidence and dignity, in an environment of global sustainability, in the conviction that there can be no sustainable and socially balanced development if, at the base, the global food system does not maintain a balance between its actors.