Sharif Digital Repository

To mitigate global warming and fossil fuel shortages a novel oxy-fuel combustion power plant integrated with a power to gas system is proposed. A net-zero emission MATIANT cycle with inherent CO2 capture ability is selected as the power cycle also providing the CO2 and power demand of the power to gas system, which comprises a proton exchange membrane electrolyzer for hydrogen production and a Sabatier reactor for methanation. A techno-economic investigation, a multi-objective optimization, and a sensitivity analysis are carried out. A comprehensive economic method that covers all economic aspects is utilized, and a Sabatier reactor model which considers the possibility of the presence of... 

The development of emerging smart grid technologies has led to more and more penetration of renewable energy resources and electric energy storage in the residential sectors. Besides, owing to the significant evolution of power electronic devices, there is a rapid growth in penetration of DC loads and generations, such as PV and electric vehicles (EVs), into the buildings and homes as a building block of the future smart cities. This is despite the fact that the electricity infrastructure of the conventional buildings is designed based on AC electricity and as a result, there would be a lot of losses due to the frequent power conversion from AC to DC and vice versa. Besides, according to a... 

In this paper, a multi-agent framework is proposed to address the expansion planning problem in a restructured active distribution network. In this framework, the objective and techno-economic constraints of participating agents are addressed in the expansion planning of power network and DER assets as well as the network and DERs optimal operation management. The agents include distributed generator owners and load aggregators which participate along with the distribution network operator (DNO) in the active distribution network planning. The proposed framework is formulated as a bi-level optimization problem with multi-lower levels in which the DNO optimizes the network expansion planning... 

The introduction of cryptocurrencies as a new form of money has attracted a tremendous amount of attention in recent years. This new financial paradigm relies on miners to validate transactions by running their cryptocurrency mining devices (CMDs). Nowadays, the significant profitability of the mining business has tempted a large number of private players in the electrical industry to employ their renewable energy resources to mine digital currency. Here, microgrid (MG) owners may use their excessive generated power to mine digital money instead of exporting it to the main grid. This paper is devoted to investigate the influential potentials of this trending business on distribution networks... 

This paper presents a novel stochastic planning framework for the integration of renewable distributed energy resources (DERs) into existing power systems without relying on new investments in the transmission networks. The upper-level problem of the proposed model aims at minimizing the total expected social cost of supplying demand that includes the expected cost of getting energy from conventional generating units and DERs, the congestion cost of transmission networks, and the greenhouse gas (GHG) emission cost, while each of the privately invested DER satisfies a specified rate of return. The lower-level problem clears the electricity market to find locational marginal prices (LMPs) and... 

Increasing the intermittent outputs of renewable energy sources (RESs) has forced planners to define a new concept named flexibility. In this regard, some short- and long-term solutions, such as transmission expansion planning (TEP) and energy storage systems (ESSs) have been suggested to improve the flexibility amount. A proper optimization procedure is required to choose an optimal solution to improve flexibility. Therefore, a mixed-integer linear programming (MILP) direct-optimization TEP versus ESSs co-planning model is presented in this paper to enhance power system flexibility. In doing so, a novel RES-BESS-based grid-scale system flexibility metric is proposed to investigate the... 

This paper presents a new framework for multistage expansion planning in active power distribution networks, in which the distribution system operator (DSO) considers active network management by clearing the local energy market at the distribution level. The proposed model is formulated as a bi-level optimization problem, where the upper level minimizes the net present value of the total costs imposed to DSO associated with the investment and maintenance of the network assets as well as the network operation, while the lower level on clearing the local energy market captures the participation of distributed energy resource (DER) owners and demand aggregators to maximize the social welfare.... 

Hydrogen as an energy carrier can play a significant role in reducing environmental emissions if it is produced from renewable energy resources. This research aims to assess hydrogen production from wind energy considering environmental, economic, and technical aspect for the East Azerbaijan province of Iran. The economic assessment is performed by calculation of payback period, levelized cost of hydrogen, and levelized cost of electricity. Since uncertainty in the power output of wind turbines may affect the payback period, all calculations are performed for four different turbine degradation rates. While it is common in the literature to choose the wind turbine based on a single criterion,... 

This paper presents a new model to maximize the utilization of existing transmission system infrastructure by optimally sizing and siting the future developments of variable renewable energy sources (VRES). The model tries to maximize the integration of VRES in power systems with minimum expected energy curtailment without relying on new investments in the transmission systems. The proposed model is formulated as a linear stochastic programming optimization problem where VRES output scenarios are generated such that their spatio-temporal correlations are maintained. The Progressive Hedging Algorithm (PHA) with bundled scenarios is utilized to solve the proposed model for large-scale cases.... 

Iran is situated in a wind belt. However, the installed wind capacity in Iran is around 300 MW, which is minuscule compared with the global 651 GW capacity as of 2021. Using novel data from wind trackers across Iran, the paper’s findings show immense potential for wind energy in Iran from a technical perspective. While attractive policies are already in place to incentivize wind energy development in Iran, the feed-in tariff (FiT) for wind energy has dropped to around 3 cents per kWh because of the sharp depreciation of the Iranian rial between 2018 and 2020. This paper shows that there is no economic justification for the development of wind farms in Iran at such low FiTs. A minimum FiT of... 

Nowadays, around 70% percent of global energy usage is consumed in urban areas. Undoubtedly, this figure will increase in coming decades due to population rise. As a result, energy resiliency can be considered as an important issue in urban context. Resilience of energy supply in urban areas can be categorized in two approaches, short-term and long-term. Short-term applies to cope with threats such as earthquakes and floods, and long-term applies to deal with impacts of climate change on global warming. In this study, literature review was applied to design questionnaire for expert survey, followed by Fuzzy analytic hierarchy process method to categorize 34 sub-criteria divided under four... 

Optimal planning of residential complex energy systems requires thorough mathematical modelling to address the interconnections between all the energy installations from the largest ones, shared by all the residents, to the smallest ones in each distinct unit. Besides, conflicting desires of investors and residents in various aspects such as reliability index make this problem more challenging. In response, this paper presents a thorough framework to obtain the optimum design and operation of a residential complex energy system from scratch. To address the appropriate interconnection between various components of such an energy system, a multi-layer energy hub structure is proposed. Besides,... 

In this paper, a robust distribution system expansion planning (DSP) approach is presented to supply the load growth locally and move toward nearly zero energy local distribution areas (LDAs). In the proposed approach, a distribution system operator (DSO) is responsible for secure and optimum operation of LDAs. Therefore, investors on distribution system upgrades use this approach to maximize the profit on investments by determining the installation year of new distribution feeders and energy resources, distributed energy resource (DER) placements and sizes considered by corresponding DSOs. The accurate AC power flow solution is used and mathematical methods are developed to model the DSP as... 

Pollutant emission is one of the most important problems the world faces. Using sustainable energies is among the best solutions which can be employed to reduce CO2 and other pollutants as in Environmental Protection Agency (EPA) standards. In this study, a case study region located in the south of Iran, including 100 households, is studied to find practical methods of investment to partially replace the required energy by renewables where the total emission is confined to the EPA standards. The solar irradiant of the region is 5.36 kWh/m2/day which causes high energy consumption (3000 kWh/day). If the government invests $495705, which is equal to the social penalty that has to be paid for... 

Transcritical-CO2, supercritical-CO2, and organic Rankine cycles are numerically investigated and compared in simple Rankine, Rankine with internal heat exchanger, and regenerative Rankine configurations to assess their thermodynamic and thermoeconomic performance indicators. Subsequently, the systems are optimized using a multi-objective optimization method. Pareto optimal solutions are provided to present the trade-off between thermodynamic and thermoeconomic indicators. In addition, scatter plots of decision variables are presented to ascertain the optimal operating range of input variables. The results show that transcritical-CO2 systems can generate the highest power. The levelized cost... 

The concept of flexibility is defined as the power systems’ ability to effectively respond to changes in power generation and demand profiles to maintain the supply–demand balance. However, the inherent flexibility margins required for successful operation have been recently challenged by the unprecedented arrival of uncertainties, driven by constantly changing demand, failure of conventional units, and the intermittent outputs of renewable energy sources (RES). Tackling these challenges, energy storage systems (ESS) as one important player of the new power grids can enhance the system flexibility. It, therefore, calls for an efficient planning procedure to ensure flexibility margins by... 

The aim of this paper is to provide a solution to decrease water consumption in the slab-cooling unit of Mobarakeh Steel Complex in Iran. The plan should give an hourly decline in water consumption during a one-year operation period to calculate the annual reduction in water consumption of the proposed process. Recommended solutions for the conversion scheme of an existing wet cooling tower to a dry or hybrid cooling system require modeling of the slab cooling process. The curves of temperature drop in slabs are extracted in this paper by modeling the transient heat transfer of the slabs in the cooling process. This will reduce the computational volume. Then, the design and optimization of... 

Algorithmic trading based on machine learning is a developing and promising field of research. Financial markets have a complex, uncertain, and dynamic nature, making them challenging for trading. Some financial theories, such as the fractal market hypothesis, believe that the markets behave based on the collective psychology of investors who trade with different investment horizons and interpretations of information. Accordingly, a multi-agent deep reinforcement learning framework is proposed in this paper to trade on the collective intelligence of multiple agents, each of which is an expert trader on a specific timeframe. The proposed framework works in a hierarchical structure in which... 

Direct reduction of iron process in steel industry has special production conditions. Low quality cooling water, low cold and high hot cooling water temperature, space limitation for new equipment installation, high value-added of product and severe effect of cooling water temperature on production rate are of these conditions. Considering technical and economic constraints and limitations, this situation makes this process an attractive case study for converting the existing wet cooling tower to hybrid cooling system. In this paper, based on integration of process, dry and wet cooling system and ambient conditions profiles, a new method for designing hybrid cooling system has been proposed.... 

Purpose: The purpose of this research was to model the impact of customer knowledge on the performance of organization with a focus on information technology industry. Furthermore, it is intended to analyze the effect of customer knowledge investment on the performance measures, by reviewing investment policies. Design/methodology/approach: The relationship between customer knowledge and performance measures was specified using literature review and grounded theory method. The system dynamics approach was then applied to analyze the impact of the customer knowledge on the performance measures. Findings: This study provided a dynamic model on the causal relationship between customer knowledge...