A group from the UVA is researching the energy limits of fossil and renewable resources
Cristina G. Pedraz/DICYT The Recognised Research Group (Grupo de Investigación Reconocido, GIR) for Energy, Economics, and System Dynamics of the University of Valladolid (UVA) is currently working on several lines of research into the energy limits of fossil resources and renewable energy.
In the case of fossil non renewable resources, the ultimate objective is to determine for how long we will have oil, coal, and natural gas if current consumer patterns continue. In order to achieve this the researchers use scenarios, i.e. hypotheses as to how events may develop in the future. These scenarios have been standardised by international bodies such as the United Nations (UN), the International Energy Agency (IEA), and the Organisation for Economic Co-operation and Development (OECD).
Luis Javier Miguel, a lecturer in Systems and Automation Engineering and the coordinator of the Research Group, explains that “this is a problem that we have been aware of for a long time and many research groups worldwide are working on it”.
The UVA researchers make estimates as to the amount of fossil resources remaining on our planet in various scenarios. These calculations are however far from simple as a multitude of variables must be taken into account. “For example, there are endless details pertaining to oil. There are unconventional oilfields in places such as the deep water of the oceans or the Arctic, the extraction of which involves destroying part of nature. There is also heavy oil, so called because it does not flow easily, which is of very poor quality; its extraction is more problematical”, he points out; these situations need to be considered when making the estimates.
The limits of renewable energy
Although renewable energy is in theory inexhaustible, either owing to the amount of energy it contains or to its natural regeneration capacity, there are limits to the making use of its potential. The Group for Energy, Economics, and System Dynamics is working to assess these limits by using a top-down method.
“If we want to calculate the maximum amount of wind energy that we can extract from the planet there are two calculation methods, top-down and bottom-up. Most estimates are made using the latter method, in which the extent and power of a wind park is calculated and is extrapolated to the surface of the Earth. The resulting numbers are very large, and although initial calculations have traditionally been carried out in this way, the figures have been reduced as many factors come into play and must be included”, Luis Javier Miguel explains.
The UVA research team makes its calculations using the top-down method. “We consider how much energy there is in the atmosphere from a thermodynamic perspective with air in movement, and see how much of this energy can be exploited because it is in areas where this is technologically feasible. Two elements are therefore taken into account, technology and economics, and in this last point the Energy Return Rate (Tasa de Retorno Energético, TRE), i.e. how much energy a source can produce and how much energy needs to be provided to exploit this resource”, he adds.
The estimates made by the group depending on these criteria reveal that the maximum amount of wind energy that can be extracted from the planet would not be sufficient to cover the current demand for energy.
On the other hand, it has used the top-down method to calculate the limits of other forms of renewable energy such as biofuels or photovoltaic energy, and has also found that the figures are more accurate than those obtained by the bottom-up method.
Analysis of technological materials
Another line of research related to the scarcity of resources is that of the analysis of the life cycle of the materials involved in new energy technologies. “We are worried that this may bring up another limit. In the case of photovoltaic energy, for instance, how much gallium arsenide (one of the materials that can be used to manufacture solar cells) is there in nature? Some materials are very scarce and there is not enough to go round”, Luis Javier Miguel declares.
|Research Group for Energy, Economics, and System Dynamics
The Research Group for Energy, Economics, and System Dynamics of the University of Valladolid is working on various lines of research into energy and economics and system dynamics as the most suitable tool for the analysis of the complex relationships between some of the variables influencing sustainability and development. It is made up of a group of lecturers and researchers from various disciplines such as physics, economics, and engineering. Although the team has been working together for several years, it was formally founded as a Recognised Research Group (GIR) of the University of Valladolid in January.