In this study, external costs due to air pollution in the city of Tehran are estimated for CO2, SO2, NOXand PM pollutants in 1390. In the first step, employing up to down procedure, these pollutants’ emission from oil products, liquid gas and natural gas fuel from transportation, industrial, household and commercial, army and departments, plants and refineries are estimated. Then the external costs due to these emissions have been computed based on presented Expenditure in universal bank and Iran’s environment organization report at 1381. The results show that external costs due to four mentioned air pollutants are approximately 18/06 thousand billion Rials (based on constant prices in 1981) in Tehran city in 1390. The maximum external costs are 83 percent for PM pollutant, 94 percent for transportation and 72 percent for gasoil fuel from point of views of pollutants type, pollutants producing section and the type of fuel consumed, respectively. Also, the total air pollution external costs due to these four pollutants are 0.18 and 0.71 percent with respect to Gross Domestic Production (GDP) of Iran and Tehran,respectively. In this study, realization of external costs is done under the light of Cost Plus method by inflation andexchange rates. In the first approach, external costs are estimated to be 24.88 thousand billiard Rials and in the second approach, they are found to be approximately 66.74 thousand billiard Rials.

Externalities and damages from externalities are unavoidable in economic processes. One of the important externalities is environmental pollution. Therefore, in order to control pollution, society must suffer social costs.Social cost in energy sector is created because of greenhouse gases (CO2, SO2 and Nox). In this paper, methods for social cost estimation and experiences of other countries in this field have been studied.Trend of social cost of energy sector in Iran shows 139% of growth rate. So, native coefficients for social cost estimatation are very important. Also, it is necessary to mention that damage cost of energy sector in Iran hace been 52050 billion Rials, which 12.9% of it belongs to power sector.

A project in any case should have a feasibility study and besides justifying the project, it should be able to make the best use of resources. There are costs for all projects which is imposed on the project and this cost should be estimated in the feasibility study of the project. External costs are costs which are imposed on society and the environment but they are not included in the price of the goods or services. This paper presents a new model to estimating the external environmental costs of a project. Therefor, first the potential environmental pollutants will be grouped and justified by the checklist method.Finally, external costs are estimated based on the said checklist using the energy balance sheet and its adjustment coefficients. And by using another checklist to look at external costs that have been counted many times, Subtract or add to the total external costs. Then the private (fixed and variable) costs of the project are taken into account and The cost is minus the total income.This is a kind of cost-benefit analysis, can be used to justify a financially project.

The subject of air pollution has become important since the emergence of industrial societies. Based on statistics provided by the spokesman of the Ministry of Health and Medical Education on December 8, 2017, in Iran, due to air pollution, 2.48 percent of gross national product is wasted. Also, the amount of damage caused to the national economy caused by air pollution is 34 trillion tomans. Annually, $ 25 billion of the world's economy becomes smoke and goes to the air, due to air pollution. Meanwhile, metropolitan areas have a very significant contribution to this damage. According to the Economic Welfare Theory, any costs that are incurred in society must be paid by the causing factors. Today, in most countries in the world, external costs are estimated and included in the pricing calculations. Therefore, it is important to calculate the external costs of air pollution in codification of an appropriate management approach. For this purpose, the aim of this research is to consider an economic, engineering and management approach to external costs caused by the emission of PM, NOx, SO2, CO pollutants in order to plan and provide targeted solutions for reducing air pollution in Karaj.

Sulfuric acid production plants are one of the main sources of sulfur oxides, emission to the atmosphere. In the present study to control sulfur oxides of Sulfuric acid plant two methods have been selected. The first method is desulfurization by ammoniac (Plant A) and the second one is a combination of the first method and dry scrubbing process with calcium hydroxide as the absorbent material) Plant B). Concerning economical investigation two techniques were carried out regarding the conclusion of the simulation. Considering the simulation results by HYSYS v3.1 software, 110 tones of sulfur oxides production were eliminated daily in two methods. As elimination of sulfur oxides was nearly the same (110 tones daily) in both methods, the external costs of production reduction of SOX as a pollutant substance is the same, too. Therefore, economic index of these two methods were calculated through COMFAR? software with two presuppositions i.e. considering the external costs and not considering the external costs, the internal rate of return (IRR) in the first method was about 46% which is more than that of the second method (18%). Moreover, the payback period in the first method was 3 years which is less than that of the second method (5 years). Net present value (NPV) as a major criterion in economics was calculated, too. In the first method NPV was more than that of the second method which is a sign of an appropriate flow of cash in the first method. In cash flow of implementation of the second presupposition, there would be 541286 million rials save as the result of reduction of external costs. Consequently, the first method has economic priority over the second method for desulfurization of sulfuric acid production plants.

Fossil fuels that are use for power generation in power plants in recent decays are finishing. In addition they are lot of pollution in environment. This pollution different ways are human health and environment. This damage imposes negative external costs that exceed private cost of power plants. The main goal of this paper is to calculated the social cost of Iranian fossil power plants based on coefficient of EPA, world bank and DOE in 1383.social cost of fossil power plant are natural gas power plant, diesel, combine cycle and steam power plants are analyzed. Results show that social cost combine cycle is least and their efficiency is more.

Despite the high potential of geothermal energy in Iran, only 100 MW of geothermal power will be produced in 2017, Because noticeable amount of subsides have allocated to fossil fuels plants in recent years. This study aims to compare final cost of geothermal electricity with electricity cost of other kinds of prevalent power plants in Iran. The levelized cost method includes investment, operation and maintenance, fuel and pollution costs of each technology which produce electricity. Comparison of final costs of electricity on export price of fules and externalities costs reveals that high capacity factor, independence on fossil fuels and low emission costs, would make geothermal power plants competitive with other power plants in Iran. This study suggests that the liberalization of energy prices has a significant effect on geothermal power development in Iran and could provide the possibility for exporting more natural gas to foreign countries.

Many reports that appeared during the last 20 years have shown that atmospheric pollution causes serious damage to human health and to environment. Electricity generation from fuel fossil is one of the major sources of pollution and considerable share of this damage. The price of electricity in Iran, as in many other countries also, includes only the production of private costs and ignores any other external economic effects. In this research, the external costs of SO2 and NO2 emissions have been calculated for Shahid Rajaii Power Plant. Shahid Rajaii Power Plant is located at Tehran – Gavin free way. The system of Shahid Rajaii almost depends upon fuel oil, gas oil and natural gas. It's total capacity is almost 2000 MW. The system is based on fire Power Plant which consists of 13 units. There are 4 steam turbines with 1000 MW capacity, 6 gas turbines with 640 MW and 3 steam units with 375 MW. In this paper, the external costs have been accounted for unit steam of power plant. The SO2 and NO2 emissions were compared with international standard of ambient air on four seasons, and in two conditions of Normal and Maximum load. The resulting external costs of SO2 and NO2 emissions were achieved about 444.226, 276.069 Ris/kWh.The results shows that the external costs of SO2 emission is highest due to high usage of fuel oil.

Up to now, many studies have been conducted to investigate the role of nuclear energy in reducing environmental costs and climate changes considering the different economic models and energy scenarios in different countries. However, to best of our knowledge, there is no report on this subject in Iran. This study presents a model based on dynamic programming which compares the environmental costs of nuclear power plants with other power plants such as fossil, renewable, gas, steam and combined cycle plants. This model evaluates the impact of external costs in the future planning of electrical energy and by considering baseline and nuclear scenarios, impact studies of external costs are performed. In order to verify the proposed model, the results were compared with the available data and MESSAGE results, and the accuracy of this model was proved. According to this research, nuclear power is an effective strategy for reducing environmental pollution in the future.

According to definitions, external costs are the harmful results of economic activities. This costs represent as social and environmental costs. In the other words, producing a product is attendant with some costs for environment and this cost is not calculated in final price of that product. Paying no attention to this external costs, cause the destructive effects on environment and natural resources. In the energy sector of country, external costs are being imposed some costs on society and environment and cause water and air pollution and reduce the level of the freshwater. Replacing renewable energies can reduce this costs. Based on recent studies, external cost of combined cycle power plants is less the others. According to potential of wind, solar, biomass and geothermal energy in Iran, we can improve our level in renewable energies in future. Not only the environmental costs of renewable energy is very low but also the water footprint in solar and wind power is less than other power plant.