Developing hydropower plants is a successful strategy for sustainable energy production in countries. On the other hand, due to the high capacity of energy production in the pumping power plant sector, the strategy of saving and continuous exploitation of these power plants is one of the successful policies of governments. Therefore, in this research, the optimization of energy production and maintenance costs in one of the large storage pump power plants in Iran has been discussed and investigated based on the optimization mathematical model strategy. Therefore, a Mixed Integer Nonlinear Programming mathematical model was developed in this field. Due to the uncertainty in the presented mathematical model, the fuzzification strategy was used in the mathematical model. On the other hand, in order to achieve the optimal production plan, an energy production cost optimization policy has been presented to reduce the difference in supply and demand in the energy production network. In order to evaluate the presented mathematical model, four meta-heuristic algorithms of Multi-objective Keshtel Algorithm, Multi-objective Simulated Annealing, Non-dominated Ranking Genetic Algorithm and Non-dominated Sorting Genetic Algorithm II were used with binary coding. The results of this research have shown that the solution of the meta-heuristic NRGA algorithm has been done despite the approximation of the optimal solutions in a suitable period of time, and the results of the research indicate the applicability of the presented model in the studied power plant. Therefore, according to the level of optimization performed in the case study, it has caused the improvement of planning by 7% to 12% and effective optimization processes.

In the current conditions of the world, preserving energy and creating sustainable sources has double importance. Therefore, it is necessary for the governments to move towards the use of sustainable energy in order to preserve resources and energy as well as generate income. The current research was conducted with the aim of producing sustainable energy using the hydroelectric method and providing an adaptable economic model for Mashhad Water and Wastewater Company. To ensure that the results are generalizable to any condition, location, and time, the calculations were arranged in such a way that if the required specifications for generating electricity through hydropower—based on technical principles and formulas from reliable scientific references—are considered as primary input data, the secondary data will show the amount of electricity generated and the resulting revenue based on the electricity purchase tariff.  Finally, the decision maker or investor, by calculating the amount of fixed and annual variable costs for the implementation of such a project and entering it into the necessary formulas, can calculate economic indicators such as the cost price of each kilowatt hour and the internal rate of return. Investment return period (IRR), net present value (NPV) of the project to decide whether or not to invest and to make a decision with their help. The results showed that in the studied sample with a flow rate of 0.075 m2/s and a height of 8 m, the amount of electricity produced is 30,077 kw/hr/year with a cost price of 79,000 Rials, which means that the project is not economical with the values ​​of this sample.

The most common form of large-scale energy storage system is of hydroelectricity Pumped-storage. These types of storage systems were originally developed to help generate electricity during peak times and also as a backup for nuclear power plants. Examining the recent trends in the design of the electricity market and the increase in the unstable production of renewable energies, provides the possibility of providing other services by the  hydroelectricity Pumped-storage, which, while earning additional income for the power plant, also helps the power system. While market design issues have evolved since their inception, there are still ways in which designs can be improved to better understand the value of all the capabilities of pumped storage systems while still maintaining a fair and unbiased view of the electricity market. This article addresses some of the problems that may limit the full valuation of hydroelectricity Pumped-storage in today's markets and suggests solutions for these problems.

Increasing global warming is the result of the gradual accumulation of greenhouse gases in the living environment. Energy production systems in general and electricity production in particular is one of the effective factors in the production of greenhouse gases. Therefore, on the one hand, environmental considerations and on the other hand, the limitation of fossil resources have made it necessary to change the energy production system and replace fossil fuels. In this regard, the use of renewable energy resources such as hydropower can be a good alternative to fossil fuels. This article has studied the effect of hydropower consumption on Iran's environment. Hence article has estimated the short-run and long-run relationship between hydropower consumption and different measures of environmental degradation including ecological footprint, carbon footprint, and CO2 emission in the Iranian economy during 1980-2018. For this purpose, the Autoregressive distributed lag (ARDL) approach has been used. The estimation of the specified models indicates the existence of a long-run relationship between the variables included in these models and shows that in the short and long run, there is a significant negative relationship between hydropower consumption and carbon dioxide emissions, and carbon footprints. In other words, the use of hydropower in the short and long run reduces the carbon footprint and emissions of carbon dioxide. Hydropower also affects the ecological footprint in the short run.

Renewable Energy Sources (RES) are well-defined as energy sources, that are in abundance within the natural surroundings and are much inexhaustible. In addition, hydroelectricity (HE) is a vital part of world renewable energy supply and Hydropower remains a bulk source of electricity generation because of its environmental friendliness in nature. Modeling is the analysis of the non-linear models which represent the fundamental parts of the Hydropower plant (governor, turbine, servomotor). This paper studies accurate and elaborate hydraulic turbine and governor models and its implementation in MATLAB/Simulink combined with the Sims cape Power Systems (SPS). An effort has been created to develop a plant model and examine the suitableness of controllers during a governor model for fault incidence within the system by means Simulink based simulation. The Ziegler– Nichols tuning methodology was applied for specifying the gain coefficients of a governor (PID-PI) under 50% of load demand from the plant. Also, MATLAB/Simulink gave the chance to record and compare the figures of the plant with PID & PI controllers through simulation tests within the commonest cases (three-phase fault, load demand variation) with a view of finding out the potency and therefore, the stability of the system.

In this paper, copulas and Archimediean copulas (especially with hyperbolic generator) are investigated and it is shown how to use this type of functions in the stochastic frontier analysis. Then we study the efficiency of hydropower plants located on prominent dams in Iran, and based on their performance in 1399 we use data envelopment analysis and stochastic frontier analysis and copulas functions to rank them. In the present study, among the 58 mentioned dams, the dams with an average practical production capacity of at least 10 MW are evaluated. The number of these dams is 29. The calculations show that Gotvand Dam is in the first place and the Mulla Sadra dam has the last rank.

Although Ethiopia is one of the world's fastest-growing economies, access to sustainable energy and cutting-edge clean energy technology remains a major concern. The government is making significant efforts to generate renewable energy and provide more access to its citizens. Despite this, traditional fuels (charcoal, fuel wood, dung cakes, and agricultural waste) account for around 87 percent of Ethiopia's energy use, and they pose a range of health and environmental risks. Solar, hydro, wind, and geothermal resources abound in the nation, but only 5% of the country's total hydroelectric capacity is being used; while, the rest is either underutilized or underdeveloped. An in-depth look at Ethiopia's renewable energy potential, as well as the opportunities and problems it faces, is presented in this review. With a combined installed capacity of over 7000 MW, hydropower and wind power are the most promising renewable energy sources in Ethiopia as of yet. It is hoped that this assessment will shed light on how Ethiopia can harness and maximize the use of its abundant renewable energy sources.

The main endeavor in this paper is to study on 32 fundamental Iranian dams and investigating efficiency scores and also ranks of placed powerhouse on them by using data envelopment analysis and stochastic frontier analysis methods in 1393.Applying copula technique in the stochastic frontier analysis is an advantage to our study between similar activities. EMS and MATLAB programs have been used to evaluate efficiency of centers by any models. To have a unique result, we use the average of scores by four models in any center and it is seen that Sefidroud has been selected the best efficient center and also Taleghan is in the last order. Also for comparing results of the mentioned four models, we use correlations which are based on ranks of the hydroelectricity centers in every model. The minimum compatibility is between results of BCC and SFA-Clayton models which is 63.86% and the maximum compatibility is between results of standard SFA and SFA-Clayton models which is 99.41%. Meanwhile compatibility between results of CCR and BCC models is 72.10%.

In recent years, the trajectory of energy policy-maker in Iran towards the expansion of renewable electricity generation capacity has raised the possibility that, with future increases in this capacity, issues stemming from the intermittency of renewable electricity may gradually emerge within the power grid. Consequently, it can be expected that in the future, a gradual increase in storage capacity through pumped-storage hydroelectricity units will turn to a necessity to alleviate such issues. Considering the challenges associated with investment risk and the financing of pumped-storage projects, this study endeavors to propose a market-based conceptual model for policy-making in order to foster investing in pumped-storage units. In a way that such a model would enable these units to increase their revenues through the provision of ancillary services and peak shaving and reducing their income risks. Additionally, beyond presenting the conceptual model, efforts have been made to offer a set of policy recommendations, such as pricing policies and technology ranking, to improve the performance of policy-making.

Introduction: Urban water and wastewater systems should be constructed and designed within the framework of sustainable development. Therefore the assessment of environmental impacts of these systems’ construction and operation is an essential issue. One of the environmental impacts is the global warming in which the equivalent carbon dioxide has the most important role. The equipments, energy and chemical materials used in drinking water cycle (including the phases such as withdrawal water from its resources, water treatment, water distribution, wastewater collection and treatment) have environmental impacts such as the intensification of global warming due to the increase in greenhouse gasses emission. There are various tools for sustainability assessment of water and wastewater systems. Life Cycle Assessment (LCA) is one of these tools. Unlike the three decade records of applying the LCA in the world, this method has been rarely employed in Iran to resolve the problems of real water and wastewater systems. In this study, the LCA of drinking water system has been implemented in order to estimate its impact on global warming and to examine different cases with minimum environmental impacts. Determination of the water cycle phases with the maximum impact on global warming has been also aimed. In this regard, released equivalent carbon dioxide in life cycle of drinking water was estimated by means of SiamPro software. Sari, a city (in north of Iran) in which drinking water is supplied from wells, has been selected as the case study. Three different scenarios for replacing groundwater resources by a dam reservoir (Shahid Rajaee dam) were studied. Materials and Methods: In the present research, Sari city is selected as the case study (Figure 1). Population of the city is about 350, 000 in which 57, 000 inhabitants profit by the wastewater collection and treatment system. Drinking water cycle is divided into four phases including water withdrawal from its resources, water distribution, wastewater collection and wastewater treatment in which the electricity is supplied from thermal power plant. Figure 1. Map of the studied area Because of the nonexistence of required infrastructures, drinking water in Sari city was supplied from underground water resources before July 2015. In other words, drinking water in Sari city was supplied from 28 wells with discharge of 1180 l/s. 18% of this amount was lost due to the leakage. On the other hand, underground water resources have been exposed to pollution due to the usage of farming fertilizers and operating cesspools. Therefore, replacing underground water resources by Shahid Rajaee dam has been mooted. In this regard, water will be transferred from Shahid Rajaee dam to Kiasar water treatment plant. Then the treated water will be transferred to Sari city. Wastewater treatment plant of Sari has been designed in four modules. The first module which has been operated since 2010, serves about 105000 people. The average and the maximum input discharges of this module are 269 and 546 l/s, respectively. Three scenarios have been considered for replacing underground water resources by Shahid Rajaee dam. These scenarios are: 1) Supplying a part of Sari drinking water demand from Shahid Rajaee dam; 2) Supplying the total drinking water demand from Shahid Rajaee dam; and 3) Supplying the total drinking water demand from Shahid Rajaee dam and using hydroelectricity. It should be noted that the environmental impacts of dam construction has not been considered in these Scenarios. SimaPro is one of the common software for assessing the life cycle. In this study, SimaPro 5. 1 is employed for calculating the greenhouse gasses produced in water and wastewater systems. Discussion of Results: The total amount of the equivalent carbon dioxide produced in drinking water life cycle in Sari city is presented in Figure 2. According to this figure, the total amount of the equivalent carbon dioxide produced in drinking water cycle is 0. 392 in which the phase of withdrawal water from its resources has the greatest part (about 60% of the total equivalent carbon dioxide) in producing the greenhouse gasses. Water distribution network, wastewater treatment plant and wastewater collection network have portions of about 20%, 12% and 8% respectively, in producing the greenhouse gasses. Figure 2. The equivalent carbon dioxide produced in drinking water life cycle in Sari According to the obtained results, water supplying from the Shahid Rajaee dam will reduce the environmental impact to a great extent. Scenarios 1 and 2 with common electricity production (in which 500 and 1500 l/s water was respectively supplied from Shahid Rajaee dam and was treated in Kiasr water treatment plant) reduce 84% and 86% of greenhouse gasses production in the water withdrawal phase, in addition to supplying water with higher quality. In scenario 3 with hydroelectricity, 89% of greenhouse gasses produced in the water withdrawal phase is reduced (Figure 3). The equivalent carbon dioxide produced by various agents in itroduced scenarios are shown in Figure 4. Figure 3. The equivalent carbon dioxide produced in the present situation and various scenarios Figure 4. The equivalent carbon dioxide relevant to various agents in scenarios 1-3 Conclusions: It can be concluded that operation of Shahid Rajaee dam and Kiasar water treatment plant and using hydroelectricity would lead to a great reduction in electricity consumption and producing greenhouse gasses. Another result is that the biggest share among the factors producing carbon dioxide is associated to electricity.