In this paper, a novel risk-based, two-objective (technical and economical) optimal reactive power dispatch method in a wind-integrated power system is proposed which is more consistent with operational criteria.  The technical objective includes the minimization of the new voltage instability risk index. The economical objective includes cost minimization of reactive power generation and active power loss. The proposed voltage instability risk employs a hybrid possibilistic (Delphi-Fuzzy)-probabilistic approach that takes into consideration the operator’s experience, the wind speed and demand forecast uncertainties when quantifying the risk index. The decision variables are the reactive power resources of the system. To solve the problem, the modified multi-objective particle swarm optimization algorithm with sine and cosine acceleration coefficients is utilized. The method is implemented on the modified IEEE 30-bus system. The proposed method is compared with those in the previously published literature, and the results confirm that the proposed risk index is better at estimating the voltage instability risk of the system, especially in cases with severe impact and low probability. In addition, according to the simulation results compared to typical security-based planning, the proposed risk-based planning may increase the security and economy of the system due to better utilization of system resources.

Approximately 2. 4 million tons of bagasse are produced each year in Iran, most of which are currently treated as waste adding to serious environmental concerns. Application of bagasse for energy production is a sustainable solution to supply the required energy within the sugar refineries and export the surplus electricity to the grid. Currently, the energy demand in Iranian sugar mills is mainly supplied by fossil fuels (natural gas or mazut). Bagasse fluidized bed and fixed bed gasification plants would respectively lead to save 59, 250 and 21, 750 tons of CO2 annually, compared to gas power plants of the same scale. The present study aims to compare the environmental economic analysis of electricity generation in 10-MW gas-fired power plants with that electricity generation in bagasse gasification plants (with fluidized bed and fixed bed reactors) exemplarily in Iran. The bagasse fluidized bed gasification option (with IRR of 28. 6%) showed the most promising economic viability compared to bagasse fixed bed gasification and gas power plant cases with IRR values of 25. 09 and 21. 94%, respectively. Furthermore, bagasse gasification options were potentially characterized by a better environmental performance compared to fossil-fuelled options. On the other hand, the obtained levelised cost of electricity at gas power plants (2 cents/kWh) was lower than the global range and lower than bagasse gasification cases (7-9 cents/kWh). The results revealed the vital need of biomass power plants to governmental support in order to compete with fossil power plants by participation of private sector.

The production and supply of natural gas in Iran is monopolized in the hands of the Ministry of Petroleum and prices are set by administrative decisions. However, given that gas based power plants use it as an input to meet the needs of end users of electricity, optimal price of natural gas is related to the final price of electricity. We use time series data for the period 1989 to 2016 to estimate the price elasticity of gas demand. We first estimate the price elasticity of gas demand. We then calculate the efficiency of natural gas production at scale and calculate the final cost of the natural gas produced. We then calculate the coded price of gas delivered to power plants. The actual cost of supplying one cubic meter of natural gas to power plants in 2015 was 800 Rials. The natural gas prices based on estimated Ramsey price for the years 2015 and 2016 for the gas delivered to the power plants are 8589. 71 and 9377. 91 Rials per cubic meter respectively. We can thus conclude that current administrative prices for natural gas in the power plants sector are not optimal.

The increasing emission of greenhouse gases as the most crucial factor in global warming has made this a global concern in recent years. One concept proposed to better understand the amount of greenhouse gas emissions is the carbon footprint. Carbon footprint is the amount of greenhouse gases produced by a particular product or activity in its simplest definition. Since the power generation industry is one of the most highly emitting sectors, the study of carbon footprint has also become significant. This is primarily because fossil fuels are still the number one energy source for electricity generation, and even coal-fired power plants, which have the highest greenhouse gas emissions, will be the number one source in the coming years. They will still have a high share. Therefore, in the present study, while examining the concept of carbon footprint and its calculation method in the electricity industry, in a case study of South Khorasan province, the carbon footprint from steam and combined cycle gas and diesel power plants has been compared with Tabas coal-fired power plant. The obtained results show that the site's elevation according to the air density can have up to 10% impact the carbon footprint of the combined cycle power plant, and sites with low height should be chosen as much as possible. Also, the carbon footprint of the coal-burning power plant with a value of 968 grams per kilowatt hour is far higher than other fossil power plants with a value of 579 grams per kilowatt hour.

Sustainable energy development is one of the requirements for the continued growth and sustainable development of societies and humanity. The main purpose of this study is to plan the supply of sustainable electricity by share of each type of the share of different power plants in the country.The methodology of this study is applied based on the purpose and has been done by mixed method (documentary, qualitative and quantitative). This research has been collected and analyzed using the data obtained from the study of documents, using (selected model) MESSAGE software and in the form of three reference scenarios, energy sustainability and high fuel price, the optimal composition of the country's power plant until 2050 has been investigated and proposed.Based on results and the model outputs, the optimal power plant composition in the form of energy sustainability scenario is the priority of combined cycle, nuclear and renewable power plants, respectively. Also, according to the findings, nuclear power plants are in the second place in the reference scenario and the sustainability scenario, and in the third place in the fuel price increase scenario. The results obtained from this study, considering the need for sustainable development of electricity in the country and according to the upstream documents and laws, it is necessary to prioritize the development of power plants, respectively.

Ocean energy, as a renewable resource that covers a large area of the earth, is increasingly used for power generation in forms of wave, tidal and thermal. Ocean thermal energy conversion (OTEC) systems utilize from the difference between the temperatures of surface and deep water and drive a thermodynamic Rankine cycle to generate electric power. The generated power of these plants depends on the temperature of the surface water as warm source. Due to the variation in the temperature of ocean surface, the output power of the OTEC system frequently changes in the year. This uncertainty nature results in the variation in the generated power and so, integration of large-scale OTEC generation units to the power system is a challenging problem. Thus, new techniques must be developed to study the effects of these variable resources on the power system. In operation studies of power systems, the balance between generation and consumption is important and from reliability point of view, some spinning reserve must be scheduled to prevent load curtailment in the events such as forced outages of generation units, transmission lines and so on. In a power system containing large-scale OTEC power plants, the uncertainty nature of these plants must be considered in the reserve scheduling. Thus, for this purpose, a reliability model considering both failure of composed components and variation in the output power, is developed for OTEC units. To determine a suitable multi-state model for OTEC units, fuzzy c-means clustering technique and XB index are utilized. Then, the proposed multi-state model is used to determine spinning reserve value of a power system containing OTEC plants using of the modified PJM method. Numerical results associated to RBTS and IEEE-RTS present the effectiveness of the proposed technique for operation studies of power systems containing OTEC systems.

The recent state of electrical system comprises the conventional generating units along with the sources of renewable energy. The suggested article recommends a method for the solution of single and multi-objective optimal power flow, incorporating wind energy with traditional coal-based generating stations. In this article, the two thermal power plants are replaced with the wind power plants. The techno-economic analysis are done with this state of electrical system. In proposed work, Weibull probability distribution functions is used for calculating wind power output. A non-dominated sorting based multi-objective moth flame optimization technique is used for the optimization issue. The fuzzy decision-making approach is applied for extracting the best compromise solution. The results are authenticated though modified IEEE-30 bus test system, which is combined with wind and thermal generating plants.