ارزیابی و بهره برداری آثار جانبی مرتبط با انرژی در بخش صنعت

The scope of this paper is to comparatively evaluate the effectiveness of alternative policy measures in reducing impacts from atmospheric pollution generated from industrial energy use. The evaluation procedure relies on the assessment of energy-related externalities by exploiting the methodology developed in the framework of the ExternE project. The analysis focuses on 2 industrial units located in the Greater Athens area and examines three types of abatement measures that can be used independently of the extent energy saving or end-of-pipe emission reduction measures are used: substitution of fuel oil with natural gas, relocation of the units several hundreds of kilometers far from Athens and increase of stack height in the same site. It results that the use of natural gas is by far the most effective among these measures, leading to a reduction of more than 90% of both local and regional damages. The relative effectiveness of the examined measures does not change if the significant uncertainties associated with the accounting procedure are taken into account, while inclusion of the external cost due to greenhouse gases emissions is further accentuating the advantages of natural gas. Moreover, it is shown that the quantifiable energy-related external costs of a single industrial product, may be very low compared to the corresponding private costs, but they sum up to significantly high damages to society if we take into account the total energy consumption in the industrial sector.

The industrial sector is a major contributor to atmospheric pollution, with energy consumption in the plant representing a significant source of atmospheric releases, especially of SO2, NOx and particulate matter. Depending on the temperature of exhaust gases and the stack's design parameters, as well as on the meteorological conditions at the site, these primary pollutants are dispersed in the atmosphere before precipitating and negatively affecting human health and ecosystems. Moreover, following chemical reactions in the atmosphere, SO2 and NOx are gradually transformed into secondary pollutants (ozone and aerosols), which are responsible for severe impacts on various receptors located at several hundreds of kilometers far from the source. Impacts of atmospheric pollution impose costs on society which are often not at all or only partly considered in the production cost and in the market prices of the respective industrial products. In addition, greenhouse gases (GHG) and especially CO2 emissions released from fossil fuel combustion constitute another source of social damages, in particular to forthcoming generations. The existence of these costs—the so-called external costs—constitute a severe market failure leading to the misallocation of scarce resources, since producers and consumers come to decisions that may be optimal for them but not for the society as a whole. Although the concept and implications of environmental externalities were well founded within neoclassical economics, attempts for their quantification have basically started only in late 1980s. The focus was on the external cost of electricity generation because of the key-role electricity plays in modern economies and the existence of several competing technologies, each with different environmental side-effects. Early studies were based on a top-down approach by first estimating aggregate damages for different impact categories that are subsequently attributed to various emissions for calculating external costs per unit of emission on the basis of emission inventories (Hohmeyer, 1988 and Hohmeyer, 1992). The bottom-up approach—known also as the impact pathway approach—was developed in early 1990s and is generally considered as providing more reliable external cost estimates that are site- and technology-specific. The analysis begins with determining the pollutants released from a specific source, uses dispersion models together with detailed information on the distribution of receptors and dose–response functions for calculating physical impacts, which are translated into monetary terms by means of economic valuation techniques. The so calculated marginal damages have the additional advantage of allowing for the consideration of variations due to technology choices and siting decisions. The ExternE project of the European Commission is one of the largest in scope and most widely appreciated studies using the bottom-up approach. Starting from the electricity generation sector, the developed methodological approach has subsequently been accommodated to the particular characteristics of the transport sector which is another major contributor to atmospheric pollution (European Commission, 1998; Friedrich and Bickel, 2001). Results of these studies and their exploitation in policy making are already abundant in the literature (e.g. Eyre, 1997; Krewitt et al., 1999; Krewitt and Nitsch, 2003; Mirasgedis et al., 2004; Int Panis et al., 2004). Energy-related externalities of the industrial sector have only partly addressed, as fraction of the overall damages produced by selected industrial processes. Specifically, the ECOSIT project has adopted and extended the ExternE methodology with the objective to quantify for specific innovative industrial technologies the damages associated with as much of the products’ life cycle as was relevant (European Commission, 2003). The results of the study show that the calculated external costs strongly depend on the nature of the product, the process layout and the location of units, and should not be generalized and extrapolated to other situations. However, if the focus of the analysis is restricted to energy-related externalities of industrial activities the results can provide valuable information to policy making, independently of the products’ type. It is true that the external costs associated with industrial energy use are relatively small if reduced to the total production cost, because energy itself represents in most cases only a small part of the products’ added value. Moreover, they could be small in comparison to total external costs produced by the specific industrial process. Nevertheless, the industrial sector as a major energy consumer is expected to significantly contribute to total energy-related externalities and their quantification could significantly assist in combating atmospheric pollution and climate change, especially if due to the location of industrial units the released emissions affect densely populated areas. It is clear that energy saving and end-of pipe emissions abatement measures are the priority actions that should be implemented in all industries in order to enhance their eco-efficiency. However, emissions concentrations in urban centers can be further alleviated by adopting more drastic interventions such as fuel shifts and relocation of units. The aim of this paper is to exploit the ExternE methodology for assessing the relative effectiveness of alternative abatement measures in reducing damages caused by energy-related atmospheric pollutants emitted from two industrial units located in the Greater Athens area in Greece. The focus is on measures that can be implemented independently of the extent energy saving or end-of-pipe emission reduction techniques are already introduced in the units under consideration. Namely, three types of commonly implemented abatement measures are considered: increase of stack height for facilitating the rapid dispersion of the exhaust gases, substitution of heavy fuel oil by natural gas and relocation of plants to industrial parks in the North or South of Greece. Additional information is provided to policy makers by estimating climate change externalities in each case. The obtained results are verified by taking into account the many uncertain parameters involved in the assessment of externalities. Among the different approaches used to handle uncertainty in external cost estimates, sensitivity analysis is clearly the simplest one producing “low”, “medium” and “high” cost values by altering a small number of crucial parameters (European Commission, 1995). However, total uncertainty results as the combination of the uncertainties characterizing the several input parameters used in the accounting procedure. Thus, more sophisticated approaches relying on probability theory (IVM, 1995; Rabl and Spadaro, 1999), Monte Carlo techniques (Morgan and Henrion, 1990) or fuzzy logique (Mirasgedis et al., 1999) have been proposed in order to provide more reliable estimates of the plausible range of relevant values. In the context of this study, the uncertainties of the estimated externalities have been analyzed on the basis of the probabilistic quantitative approach presented in the most recent update of the ExternE methodology (European Commission, 2005). The remainder of this paper is structured as follows: the accounting procedure is presented in Section 2 providing a summary description of the Impact Pathway Approach (IPA) developed and continuously improved in the framework of the ExternE project, as well as of the technique used in the treatment of uncertainties. Section 3 gives the necessary information regarding the contribution of industry to total atmospheric emissions in Greece and the details specifying the two case studies. Section 4 presents and discusses the obtained results, while concluding remarks are included in Section 5.

The analysis presented in this paper shows that the assessment of energy-related externalities in the industrial sector can provide valuable support in the design of atmospheric pollution mitigation policies. The ExternE methodology as implemented in the EcoSense 4.0 model is proven as an effective tool for this purpose, provided an appropriate scaling-up of the considered units is performed, in order to fit to the scale of large emission sources typical of the power generation sector, for which it was initially designed. The present analysis examines two units located in the Greater Athens area, a region already suffering from increased concentrations of atmospheric pollutants. This area concentrates more than one third of total industrial units of Greece contributing to a higher or lesser degree to the whole problem of atmospheric pollution in urban centers. The question raised is which type of policy measures should be implemented for the particular case of industries located in this area in order to contribute to the overall target of mitigating atmospheric pollution in urban centers for protecting human health and in accordance with relevant EC directives. The analysis starts with an overall assessment of the total quantifiable external cost related with energy use in the selected units in the present situation. The obtained results show that although energy-related externalities account for only a very small percentage of the private production cost in industrial units, they constitute a significant cost figure if compared to the private cost of fuel oil. It is therefore confirmed that the damages caused to society by energy use in the industrial sector sum up to considerable damages if we consider total energy consumption of industrial units, especially of those located close to urban areas. It is worth noticing that half of the total quantified external cost refers to the anticipated damages of the global warming effect. Hence, the very first priority for mitigating atmospheric pollution in urban centers and contributing to climate change abatement in the global level is to use more efficient energy conversion technologies and minimize energy losses in the industrial processes. It is also found that for the particular case of Athens the distance from the most populated city center is not the most critical parameter, but it is rather the exact location of the unit in relation to the sea and the predominant wind direction. Next, the performed analysis focuses on the comparative assessment of three pollution mitigation measures that can be implemented independently of the extent energy conservation or other end-of-pipe pollution mitigation measures are already in place. On the contrary, the obtained results and more specifically the resultant damage cost per ton of pollutant offer valuable information to relevant decisions. Concerning the pollution mitigation measures, the substitution of fuel oil by natural gas is proven by far the most effective solution. Since the largest part of Greater Athens area has already an access to the grid of natural gas it seems that a policy for encouraging or imposing the penetration of natural gas in all industrial units in this area is strongly recommended. Such a shift is not expected to have any effect on natural gas prices because of the small share of the Greek market and especially of the Greek industrial sector on total fuel consumption in the EU and worldwide. The measure of relocation far from the city center is also very effective in reducing local damages. However, the overall impact of relocation on total damages produced by energy use depends on the location of the new site, with sites in southern Greece appearing more advantageous as being surrounded by the sea. Finally, the increase of stack height, although reducing local damages by 20–30%, they do not practically influence damages outside this local scale. It is clear that policy makers have to carefully consider the pros and cons of each candidate solution including all related distributional effects. In this sense the relocation option besides the reduction of pollution damages far from the densely populated Athens area has on the one side a positive impact on regional development and on the other side negative effects on employment in Attika region. External cost estimates are often strongly disputed because of the overall uncertainties associated with the assessment of externalities, in particular with the assumptions, simplifications and ambiguities inherent in all steps of the IPA. However, the performed uncertainty analysis shows that despite these uncertainties the conclusions regarding the comparative assessment of pollution mitigation options are very robust. Hence, it is proved that the assessment of energy-related external cost is a valuable instrument for environmental policy making in the industrial sector. In particular, relevant estimates can be fully exploited on a comparative and not necessarily on an absolute value basis for prioritizing pollution mitigation options and supporting siting decisions.