نشریه انرژی ایران
سال هفدهم شماره 1 (پیاپی 62، بهار 1393)

In this paper, we have analyzed economical and energy efficiency dimensions of old tractors replacement with new efficient types. The main goals is economical, technical and environmental assessment of existing plan and suggestion new optimal and favorite plan. We use special model for this work that was established by LEAP software. Very different scenarios were evaluated by this model. The result of research shows, although fuel consumption of all active tractors in Iran was 1265 million liter per year in 2010, but it will increase to 1890 million liter in 2021 by reference scenario. If replacing all of old tractors, fuel consumption will decrease dramatically and it will reach to lower than 1300 million liter per year. Furthermore, social benefit of implementation this plan will be to 300 MM$ up to 2021

This paper implements and designs a new under frequency load shedding in competitive electricity market. In this paper at first optimal amount of load shedding is achived to restore the power system stability and put steady state frequency in allowable range after disturbance occurring. Then a technoeconomic multi-objective function is introduced to detect an optimal load shedding scheme considering competitive electricity market. The proposed problem include maximum GENCOs profits considering electricity power not supplied penalty cost and minimizing congestion cost in competitive electricity market. In order to solve multi objective function, a partical swarm optimization (PSO) is used to find the optimal value of load shedding. The proposed methodology is implement on a modified IEEE 39-bus test system. Generating output associated with the price of each generator, power output and price of dispatchable loads are calculated through performing smart market procedure of MATPOWER 4.1. The obtained results demonstrate the effectiveness of the proposed methodology in designing the optimal load shedding to restore system frequency and satisfying social welfare

Operation in micro grids containing combined heat and power generators require specific modeling and optimization methods due to interrelation between electricity and heat. In this paper after introducing a proto type micro grid and corresponding dispersed generations a multi objective problem is investigated for micro grid operation. Based on three factors: generation cost function, environmental emission and micro grid loss a three objective optimization model is proposed. Considering proposed model a genetic algorithm based method entitled Non-dominated Sorting Genetic Algorithm (NSGAII) is employed. The objective is providing simultaneous electricity and heat considering the possibility of electricity trading with external grid. Subsequently, three scenarios: using domestic boiler, gas engine contribution and micro turbine contribution are presented for providing electricity and heat demands of consumers and the best scenarios is selected at the end.

This paper implements and designs a new under frequency load shedding in competitive electricity market. In this paper at first optimal amount of load shedding is achived to restore the power system stability and put steady state frequency in allowable range after disturbance occurring. Then a technoeconomic multi-objective function is introduced to detect an optimal load shedding scheme considering competitive electricity market. The proposed problem include maximum GENCOs profits considering electricity power not supplied penalty cost and minimizing congestion cost in competitive electricity market. In order to solve multi objective function, a partical swarm optimization (PSO) is used to find the optimal value of load shedding. The proposed methodology is implement on a modified IEEE 39-bus test system. Generating output associated with the price of each generator, power output and price of dispatchable loads are calculated through performing smart market procedure of MATPOWER 4.1. The obtained results demonstrate the effectiveness of the proposed methodology in designing the optimal load shedding to restore system frequency and satisfying social welfare

In this paper, an economic analysis of replacing a single phase motors with a three phase motors and an inverter is carried out for the domestic water cooler. Considering the importance of saving energy, the enormous contributions being made by electrical motor in the residential loads, and the ever-increasing prices of energy carriers necessitate using technology to optimize energy consumption. In this study, we evaluated replacement of a three phase motor with an inverter instead of the conventional single phase motor being used in a specific timeframe in a hot and dry climate such as Kashan, where a great number of such cooler are used. Offering such technology, would lead to a softer starting in electrical motors, less breakdown owing to reduced mechanical stress on parts, reduced electric power generation and cost and less power losses in transmission lines. In all these cases energy savings can be achieved having a payback period of less of two years for the investment incurred, making this technique a superior one for such applications.

This article presents an assessment of wind energy during 20 months with the time interval of 10-minutes in Shush-tar station in Iran. Weibull distribution function was used to model the wind data. In the first phase of the study,the error obtained from Weibull distribution was compared with three other models namely, Rayleigh, Logistic and Log-normal. It was concluded that Weibull distribution is the best function to model the wind speed in Shush-tar. From the initial evaluation of wind data, it was found that the studied site doesn’t have sufficient wind potential for using large and medium scale wind turbines.Thus an economic evaluation of three small wind turbines was performed on RETScreen® software.The economical indicators like the simple payback period, the Benefit-cost ratio, the net present value, and the cost of renewable energy production showed that the proposed small wind turbines are not feasible in the city of Shush-tar. It was suggested that in addition to the study of other renewable sources such as solar energy in shush-tar,a feasibility study for installation of a hybrid system which uses both solar photovoltaic panels and a small wind turbine can be considered for the next study.

According to the Iranian Cement Industry Employers Association, Production process of cement, Compared to the production method and age of factory,requires a huge amount of energy therefor there has always been a need for finding alternative and cheap fuel sources in the world. The percent of the cost of the energy in cement industry is estimated to be approximately 25% to 35%. Hence, this industry shows a huge potential in the field of energy management as well as implementation of optimization of energy consumption. According to experts, the Bureau of Mines and Mineral Industries Ministry of Industry and Trade,In 1391 cement industries in Iran have consumed about 61.77×1012 kcal of heat energy for the producing of 71 million tons of cement. Tire-Derived Fuel (TDF) can only provide about 1.62 percent of this need. Using of the Refuse-Derived Fuel (RDF), whose its production has large potential in Iran, can cover about 25.6 percent. Reduction of 27.22 percent of fossil fuel consumption in the cement industries stem from applying the both of these fuels simultaneously, lead to gas saving about two billion cubic meters per every year. The export value of such volume of gas is equal to one billion and ten million dollars. The purpose of this paper is to estimate the evaluation and effects of using alternative fuels in the cement industry in Iran. It also deals with procedures, difficulties as well as technical and economic evaluation facing the scheme.

Differen world energy outlook with different horizons (2035, 2040 and 2050) show that demand for primary energy will increase. The energymix in 2050 will mainly be fossil based although the share of theses fuels will decrease. Accorging to some forecasts, energy consumption will increase more than 50 percent during next 30 years which most of this growth belongs to non-OECD countries. In supply side, the fastest growth will belong to natural gas and renewables. According to World Energy Council (WEC), Environmental sustainability، energy security, and energy equity are three pillars ofthe energy trilemma. The WEC has built two scenarios for fulfillment of these goals for world energy outlook to 2050. The more consumer-driven Jazzscenario has a focus on energy equity with priority given toachieving individual access and affordability of energy through economic growth. But more voter-driven Symphony scenario has a focus on achieving environmentalsustainability through internationally coordinated policies and practices. In Jazz scenario, the growth of energy consumption is more than Symphony scenario. In addition, the growth of renewables in Symphony scenario is twice of Jazz scenario.