فصلنامه مطالعات اقتصاد انرژی
پیاپی 57 (تابستان 1397)

Due to favorable efficiencies, industry increasingly utilizes combined heat and power (CHP) units. This paper reviews options for optimal location, size and operation of various CHP technologies in heat and electricity distribution networks with given techno-economic-environmental constraints, which maximizd the economic profit of CHP technologies. In our cost benefit model, heat and electricity sold to customers, loss reduction of heat and electricity distribution networks, and cost reduction in required equipment investment are considered as benefits for the utility company and, the sum of costs for capital equipment investment, operation and maintenance, and environmental emission are considered as costs. We obtain the optimal values through use of a newly developed hybrid algorithm based on shuffled frog leaping algorithm and particle swarm. The simulation results show that combination of renewable and non-renewable CHP technologies increase yearly utility company economic profit by $ 134937.09. Internal combustion engines have no role in this combination due their high environmental emission costs

This paper examines the relationship between natural gas consumption and economic growth in 11 gas exporting countries including Iran, Qatar, Venezuela, Egypt, Algeria, Russia, UAE, Libya, Nigeria, Bolivia, and Trinidad (GECF countries), using a multivariate production model for the period 1992 to 2014. The study reveals that natural gas consumption, economic growth, gross fixed capital formation and degree of trade openness are cointegrated with regard to structural breaks. When we use the Fully Modified Ordinary Least Square (FMOLS) and Dynamic Ordinary Least Square (DOLS) tests, we see that natural gas consumption in GECF countries positively affects economic growth. Furthermore, results of the joint test (short-run and long-run) of the VECM Granger causality test reveals unidirectional causality from natural gas consumption to growth for GECF countries, which proves the growth hypothesis. Regarding the direction of causality of each country in the panel, the results of the Dumitrescu-Hurlin causality test (2012) support the growth hypothesis in the case of Iran, Venezuela, Egypt, Algeria, the United Arab Emirates, Nigeria, Bolivia, while for Russia it confirms the feedback hypothesis and for Qatar, Libya and Trinidad it confirms the neutral hypothesis.

Maritime transport has a major cost advantage in the transport of bulky and heavy cargo due to its low per tonne cost. This paper assesses the demand for the two types of fuel that are used in cargo and passenger ships (bunker fuel oil and gas oil –diesel) in the world. We first estimate the total demand for maritime transport and then proceed to calculate the associated demand for fuel demand. Given the differential market characteristics of the two fuel types, we use two different equations to estimate the demand for them.
The results show that both fuel oil and diesel demand are positively correlated with the volume of maritime traffic in a significant manner. Our observations indicate that the changes in overall economic conditions affect the volume of international trade and resultant demand for fuels used in maritime transport. We also see that the demand for each of the two fuels, namely fuel oil and diesel are negatively correlated with their respective real prices in a significant manner.

This study investigates the effect of oil price volatility on country risk index of Organization of Petroleum Exporting Countries (OPEC) members for the period 2002 to 2015. We calculate oil price volatility by using an exponential autoregressive conditional heteroskedasticity (EGARCH) approach. The impact of oil price volatility on country risk index in OPEC is estimated using a Markov switching model. The result indicate that oil price volatility has different effects on the risk index in different OPEC countries. Oil price volatility has positive effect on country risk index for the United Arabic Emirates and Kuwait; negative effects for Qatar, Nigeria, Libya and; asymmetric effects for Angola, Iraq, Saudi Arabia and Venezuela. Moreover, the study results indicate that oil price volatility has the most positive effects for the United Arabic Emirates, Iraq, Saudi Arabia, Angola and the least positive impact for Kuwait and Venezuela. Furthermore, the lowest negative impact of oil price volatility on country risk index is seen for Iran and Iraq and the greatest negative impact for Qatar. It is therefore recommended that planners, investors and others institutions pay attention to the country risk index and the likely impact of oil price volatility on it before investing in OPEC member countries.

There are many studies of the determinant factors of technical efficiency of power plants, but few studies have dealt with the efficiency effect of change in prices of inputs and outputs. In this paper we report on a study that uses the parametric stochastic frontier analysis to assess the effect of reduction of energy subsidies and resultant changes in input and output prices on the efficiency of power plants. The results show that while the direct effect of subsidy reform has not been significant at the macro level in Iran, increasing the input-to-output price ratio of power plants has led to significant increases in the technical efficiency of power plants, especially those operated by the private sector

The effects of economic growth on the environment is one of the most important factors in current discussions in environmental economics. Industrialization of societies leads to further exploitation of fossil fuels such as coal, oil and gas. The combustion of these fuels leads to increased emission of toxic and dangerous gases and damages such as global warming and climate change. Therefore, in this study we use the VAR panel method to calculate the technical, scale and combination effects of economic growth on the environment of Iranian provinces for the 2005 to 2016 period. The results show that shocks to per capita income (a measure of technical effects) reduced environmental pollution (CO2 emissions). However, shocks to GDP2 (a measure of scale effects) and capital-labor ratio (a measure of combined effects) increased environmental pollution. Analysis of variance also showed that in Iran, per capita income has greater impact on environmental quality and pollution than other measures of economic growth.

The share of natural gas in Iran's energy basket is curremtly more than 70 percent. The efficient use of gas is thus a key feature of a resilient economy. This research uses productivity and data envelopment analysis to assess the productivity of gas powered power generating plants for the period 2011-2015 and where possible compares them to the targets set in the fifth development plan of the country. We use Excel and GAMS software to perform the necessary computations. We identify factors that affect productivity and pinpoint areas where improvements are needed. In the end, we use the average of the most popular multi-attribute decision-making methods (MADM) to rank gas powered power generation plants. The Fajre_Jam power plant is the most efficient and the Bid_Boland power plant is the least efficient

Energy is a driver and essential input of most production processes. In Iran and other oil rentier states, the bulk of energy consumption is from non-renewable resources (due to its abundance and cheapness). It seems that the low price of non-renewable energies in these countries lessens the incentive for increasing energy efficiency in these countries. The empirical proof of this hypothesis can clarify another dimension of the resource curse. To study the effect of resource abundance on energy efficiency, we use the sample of rentier and non-rentier countries, based on unbalanced panel data for the period 1998-2012. Our results indicate that there is a positive relationship between the ratio of natural resource rent to GDP and energy intensity, implying that higher resource rents lead to lower energy efficiency. The results also show that there is a negative relationship between energy price and energy intensity, indicating that higher fuel prices lead to higher energy efficiency.