|Home » ENVIRONMENT » Externalities and wind... » Externalities of different technologies|
The most noted project on determining the external cost of energy is the ExternE (Externalities of Energy) project, which attempted to develop a consistent methodology to assess the externalities of electricity generation technologies. Work and methodologies on the ExternE project are continuously updated. For comprehensive details on ExternE, refer to www.externe.info.
Prior to the ExternE project, studies were conducted in the late 1980s and beginning of the 1990s that gave an early insight into the importance of externalities for energy policy as a decision-making tool. An overview of the key aspects of these early studies is presented in Appendix I.
The ExternE methodology is a bottom-up approach, which first characterises the stages of the fuel cycle of the electricity generation technology in question. Subsequently, the fuel chain burdens are identified. Burdens refer to anything that is, or could be, capable of causing an impact of whatever type. After having identified the burdens, an identification of the potential impacts is achieved, independent of their number, type or size. Every impact is then reported. This process just described for the fuel cycle is known as the 'accounting framework'. For the final analysis, the most significant impacts are selected and only their effects are calculated.
Afterwards, the 'impact pathway' approach developed by ExternE proceeds to establish the effects and spatial distribution of the burdens to see their final impact on health and the environment. Then, the 'economic valuation' assigns the respective costs of the damages induced by each given activity.
The methodology summarised above was implemented in the computer model EcoSense (also within the ExternE project). EcoSense is based on the impact pathway approach and is therefore widely used to assess environmental impacts and the resulting external costs of electricity generation technologies. Moreover, EcoSense provides the relevant data and models required for an integrated impact assessment related to airborne pollutants.
Figure 4.2: Impacts Pathway Approach.
Source: European Commission (1994)
The modelling approach of EcoSense is briefly summarised in 'Methodology for the calculation of external costs of different electricity generation technologies based on the EcoSense Model' below, where the different steps for the determination of empirical results of external costs of electricity generation in the EU27 Member States are presented. It is important to note that the EcoSense model not only includes the external costs caused by conventional electricity generation in its own country but also models the pathway of emissions from conventional power plants to the different receptors (humans, animals, plants, crops, materials and so on) all over Europe ( in other words including those located thousands of kilometres outside an EU Member State). The aspect that emissions from one country pass to other countries, and, especially for climate change, to the whole world is essential to derive robust results. The objective of the EcoSense model, however, is to model cross-border effects in Europe only, and not on a global scale.
Because air pollutants can damage a number of different receptors (humans, animals, plants and so on), the task of analysing the impacts of any given emission is complex. Moreover, the final values of external effects and external costs vary between different countries and regions, since specific peculiarities from every country have an influence on the results due to a different range of technologies, fuels and pollution abatement options as well as locations.
In general, the fossil-fuel cycle of electricity generation demonstrates the highest values on external effects and external cost (coal, lignite, peat, oil and gas), of which gas is the least damaging. In the ExternE studies, nuclear and renewable energy show the lowest externalities or damages.
In almost all studies to date, the fossil-fuel cycles of electricity generation are associated with higher external costs than nuclear and renewable energies. An exception are the studies undertaken by Hohmeyer (1988) and Ottinger et al. (1990), which also show significant external costs of nuclear energy:
The most important emissions concerning electricity generation are CO2, SO2, NOx and also PM10 (particulate matter up to 10 micrometers in size). Emissions generally depend on the type of fuel used:
|Acknowledgements | Sitemap | Partners | Disclaimer | Contact|
The sole responsibility for the content of this webpage lies with the authors. It does not necessarily reflect the opinion of the European Communities. The European Commission is not responsible for any use that maybe made of the information contained therein.