GENERAL DEFINITIONS
Renewable energy sources (RES) can be defined, in general, as those capturing their energy from ongoing natural processes, like sunshine, wind, flowing water, geothermal heat flows and biological processes; they are considered renewable because their flow of energy is replaced by a constant natural process in a short period of time, which is one of the main differences between RES and fossil energy sources (University of Massachusetts, 1997).
RES can be used in different ways, either directly or indirectly, to generate some more convenient form of energy: for instance, to produce electricity through wind turbines or fuels, such as ethanol, from biomass.
Their use is not new in human history, since wood has been the primary energy source since less than 150 years ago; nevertheless, in the last century, the low price of fossil fuels caused a fall in wood use and, even today, it is one of the main obstacles to a widespread development in RES exploitation (Energy Information Administration, 2004).
In relatively recent years, during the 1970s, the concept of renewable energy began to be debated; since then, RES have gained increasing attention due to the emergence of various problematic issues related to the use of fossil fuels and of nuclear energy: in particular their exhaustibility, their polluting emissions and wastes, and quite recently their rising prices.
As a matter of fact, RES are seen as more sustainable than nuclear and fossil sources of energy: first, because they may be classified as “free energy”, which means (in engineering) an energy source available directly from the environment and which cannot be expected to be depletable by humans; besides, RES are commonly considered cleaner, in terms of their final emissions and environmental impact.
In spite of these potential positive effects, some criticisms have arisen, regarding a more extensive use of RES.
In the case of bio-energy (i.e. energy produced from biomass) the main debate refers to the opportunity cost of the land. Large areas should be used to cultivate energy crops, in order to produce significant level of bio-energy; those areas could be used to other kinds of production, or could even left wild for conservation purposes (Cliff Bowden, 2005). In this perspective, some argue that the achievement of food security by a country and its bio-energy production are in a sort of competition, as we will focus later in the article.
Before analyzing this debate more in detail, we think it is worth trying to give a definition of the term “biomass” and underline its main characteristics.
The term biomass has different definitions, often depending on the defining entity and its purposes. Nonetheless, it can be broadly identified as all kinds of non-fossil organic material that is available on a renewable basis; we include agricultural crop and wood wastes and residues, animal wastes, municipal wastes, other organic waste materials and, of course, dedicated energy crops and trees[1].
Given the high variety of raw materials, several types of technologies are used to transform biomass into bio-energy: among them, we could list direct combustion, co-firing, pyrolysis and anaerobic digestion. On the other side, final uses of biomass are various and diversified: biomass can be used for household heating, as a liquid fuel, to produce bio-fuels or bio-gas.
Some differences can be identified between biomass and the other kinds of RES. From the point of view of its availability, biomass can be considered, among RES, the most independent one from geography, being available at local level in various forms in almost every period of the year. However, geography becomes relevant again in the phase of transformation of biomass into bio-energy and its transport: collection logistics, available transformation technologies and infrastructures are crucial aspects of the biomass supply chain, as well as the distance existing between the production site and the demand (ITABIA, 2003). In this perspective, biomass can be seen as an important resource at territorial level.
In terms of renewability of the source, there is a wide diversity not only between biomass and other RES, but also among different types of biomass: some kinds of biomass are constantly renewed (e.g. municipal or animal wastes), while some others take time and a new productive process to be renovated (e.g. trees and energy crops). It is worth reminding that this second kind of biomass lies in the definition of RES too, because the time it needs to be renewed never goes beyond a human lifespan (CPATS, 1998).
Furthermore, as opposite for the other RES, the final uses of biomass for bio-energy are usually characterized by some sort of polluting emissions, even if at a lower level than fossil energy sources: in fact, these emissions would be compensated by the amount of CO2 absorbed by biomass during its life, resulting in almost no net CO2 emission. The incidence of transport in bio-energy productive process is a crucial point in the assessment of its final emission and it should be analysed case by case; however, it is generally agreed upon that total net polluting emissions of bio-energy are lower than those of fossil fuels, especially if biomass is transported and use within a reasonable distance from the production site.
In this article, we want to focus our attention on bio-fuels, a specific type of biomass obtained by the oil of dedicated crops (called energy crops), like sugar cane, soy, sunflower, among others.
Liquid biofuels usually produced are bio-ethanol, bio-diesel, as well as virgin vegetable oils. Bio-ethanol can be used in internal combustion engines and in fuel cells; bio-diesel can be used in modern diesel vehicles with little or no modification to the engine and can be obtained also from waste and virgin vegetable and animal oil and fats (lipids); while modifications in diesel engines are needed to use virgin vegetable oils.
While the introduction of energy crops can contribute in the increase in bio-diversity of areas previously dedicated to monocolture, the major benefit of biofuels lies in their lower emissions, compared to fossil fuels. Nevertheless, together with the land opportunity cost, some drawbacks in their use are usually identified: they are linked to the fact that the crops need to be grown, collected, dried and fermented, and the oil obtained needs to be transformed to be used safely by common engines. All these steps in the production chain of biofuels require particular infrastructures and technology, resulting in a higher price of the final product and, consequently, in a barrier against a more widespread use of this kind of bio-energy.
THE INTERNATIONAL INTEREST ON BIOMASS
All the above mentioned issues have gained interest in the international arena thanks to the wider debate on the increase in the atmospheric concentrations of anthropogenic greenhouse gases, its effects on global climate and the way in which they could be faced.
It has been estimated that the major part of the increased concentration of these gases in the atmosphere have been generated through fossil fuel burning and land use changes undertaken by industrialized countries. For this reason, the global community has urged industrialized and emerging countries[2] to take concrete initiatives in reducing their greenhouse gas emissions.
The promotion of a widespread use of energy from renewable energy sources is one of the most relevant of these initiatives, since it may deeply contribute to a sensible reduction in polluting emissions.
Various international meeting have been focused on the need for a reduction in greenhouse gases emissions. We can cite, very briefly, some of them.
In 1988, the Intergovernmental Panel on Climate Change (IPCC) was created by the World Meteorological Organization and the United Nations Environment Programme (UNEP). Its first report started to look at global warming as a real and urgent environmental problem.
In 1992, in Rio de Janeiro, at the United Nations Conference on Environment and Development the Framework Convention on Climate Change, setting an overall framework for intergovernmental efforts to tackle the challenge of climate change, was presented.
One of the most relevant outcome of this Conference[3] has been a document called “Agenda 21”, a plan of action to be taken globally, nationally and locally in order to pursue environmentally sustainable development, intended as a process that “meets the needs of the present without compromising the ability of future generation to meet their own needs” (Bruntland Report, 1997).
After the entry into force of the 1992 convention, ratifying countries gathered annually during Conference of the Parties to assess concrete fulfilment of their engagements.
In December of 1997, the Kyoto Protocol was drafted, during their third annual meeting. Using the information provided by IPCC, on the level of global CO2 emissions reductions needed in order to prevent further climate change, the Protocol established an international plan to achieve that target. However, although the text of the Kyoto Protocol was adopted unanimously, it only entered into force on the 16th February 2005. In fact, many industrialized countries have proved not to have the sufficient political will to fulfil the obligation of a substantial reduction in greenhouses gases emissions[4].
The full implementation of Agenda 21, and the Commitments to the Rio principles, were strongly reaffirmed at the World Summit on Sustainable Development held in 2002 Johannesburg. During the Summit, the UN reaffirmed the commitment to achieve the Millennium Development Goals (MDGs) adopted by the UN Millennium Summit in 2000[5]; it is particularly worth noting here that the 7th goal remarks the concept of environmentally sustainable development.
Energy issues clearly raise as a central point in the path toward the achievement of sustainable development goals, even though neither Agenda 21 nor the Millennium Declaration have a specific chapter on them. In fact, according to Johannesburg Declaration energy must be considered a human need, like other basic needs (food security, water, health care, and so on).
Since almost two billion people have no access to modern energy services[6]n order to ensure that sustainable development goals are realized, one of the main challenges lies in finding a balance between the growing demand for energy and its impact on the environment.
In order to fulfil targets foreseen by MDG Energy Vision[7] (2005), the provision of modern energy service to poor people all around the world should be accelerated. The achievement of this target would represent a crucial step towards sustainable development.
In order to give strength to this statement and to give an assessment of the impact of bio-energy, we will analyse the existing literature on the bio-energy, focusing mainly on its relation with food security in developing countries.
BIBLIOGRAPHY
Cliff Bowden, “Investing in renewable energy sources”, 2005; available at
“Le biomasse per l’energia e l’ambiente – Rapporto 2003”, ITABIA
Donald L. Klass, “Biomass for renewable energy and fuels”, Biomass Energy Research Association, 2004; available at
(Renewable Energy Research Laboratory (RERL) University of Massachusetts, 1997)
(1998)
(US Department of Energy – Energy Efficiency and Renewable Energy, 2005)
(Energy Information Administration, 2006)
(2005)
(2006)
(Biomass, intermediate technology development group)
(national energy foundation)
D.O. Hall and J.I. House, “Biomass energy development and carbon dioxide mitigation options ”, Division of Life Sciences, King's College London;
1
[1] For a more detailed definition of biomass, see
[2] like China, India and Brazil, both for their economic growth and for their large population.
[3] Also known as the “Earth Summit”.
[4] Article 3 charges industrialized countries with the responsibility of reducing their emissions of greenhouse gases “by at least 5 per cent below 1990 levels in the commitment period 2008 to 2012”.
[5] With the United Nations Millennium Declaration.
[6] Thus affecting all aspects of socio-economic development.
[7]The targets of the MDG Energy Vision are that by 2015:
• 100% of the world’s urban populations and 50% of the world’s rural population use modern liquid and gaseous fuels for cooking
• 50% of the world’s rural population use improved biomass stoves
• 100% of the biomass used for cooking is produced in a sustainable way
• 100% of the world’s urban populations have a basic electricity supply to meet lighting and communication needs
• 100% of the world’s health facilities and schools have electricity supply and use modern liquid and gaseous fuels to meet cooking and heating needs
• 100% of all communities have access to mechanised power