Journal of Energy Management and Technology
Volume:4 Issue: 3, Summer 2020

Nowadays, the negative effects of greenhouse gas emission, air pollution, and global warming have been increased exponentially due to population growth, especially in urban areas. To handle urbanization with minimal environmental pollution, the smart city concept has been introduced and extended significantly. Worldwide concerns on social welfare and lifestyle quality are the other important reasons that motivate cities to become smarter and more intelligent. The smart cities try to promote economic growth and improve the quality of life by providing regional development and technology utilization, especially smart-based technologies by using information and communication technology, and services. In this paper, it is attempted to present the definition, concepts, and standards to make the necessary arrangements and involved challenges in smart cities focusing on the power system requirements. Finally, by reviewing some proposed frameworks regarding the smartization road map, a sample road-map is described, especially in pioneer smart cities around the world.

The presence of new devices with their new technology makes the optimal scheduling of energy hub’s operation more complicated and challenging, however brings more flexibility. Power to gas as one of recent type of energy storages, can enable the energy hub in carbon trading market based on its carbon recycling feature. Participation in carbon emission trading market can be considered as suitable option for reducing the operation cost. In this paper, an energy hub included power to gas technology has been investigated. In addition to power to gas, the combined heat and power unit beside the gas powered boiler make the different energy conversion to each other possible. District heating network among market context has been considered as well as electricity. The demand response program as one of smart grid’s strategies has been employed beside the other control variables of energy hub. Finally, the uncertainties of problem such as demands, renewable sources production, prices are handled by using stochastic optimization method. A mixed integer linear programming formulation has been proposed for optimization of defined energy hub’s operation. The output results demonstrate that added flexibility by participation in carbon emission trading market and demand response program are capable for 2% reduction of operation cost.

Energy hubs connect multi energy carriers at the input port to various loads at the output port. The present study investigates the optimal operation of the energy hub as a centralized unit. In this paper, the main objective function is exhibited by the minimization of the total operation cost subject to a set of constraints. The cost function comprises two parts, namely the different energy carriers cost and the production cost of the environmental pollutants caused by each carrier. The constraints involved in operation problem of the energy hub include power balance, limitations of energy storages and converters. Well-known Mixed Integer Linear Programming (MILP) is used to tackle the proposed optimization model. Tidal power plant as a new renewable energy resource is also considered in the input port of the energy hub. In order to investigate the effectiveness of the model, the proposed model is examined on a test system. Considering the production cost of the environmental pollutants makes the problem to be more realistic. As a result, it is recommended to consider the emission cost in the energy hub operation problem.

The environmental air pollution according to greenhouse gas emissions and significant demand for electrical energy and water due to the growing population of the world can be mentioned as main challenges all around the world. The current study proposes a new structure for energy-efficient microgrids to deal with on-peak electrical energy load in summer days. Two ancillary services are considered in the proposed structure including solar Stirling engine and diesel plant for decreasing the successive outages of interconnected energy network in extremely-hot weather status and eliminating massive blackouts. Such services are effective solutions to provide load and minimize the whole energy procurement cost as production-side management strategies. The objective of the proposed model is to minimize the fuel cost of the diesel plant and the cost of generated electricity by the local power network considering technical limitations of the combined diesel-Stirling electricity supply system. The optimal employment of solar-based Stirling cycle and diesel engine in providing summer peak power load are evaluated in terms of economic-environmental aspects by applying the model on a test case microgrid, which verifies high performance of the model.

Energy is an important parameters for sustainable development of each country. Renewable energies are one of the main ways to reach this aim. Photovoltaic (PV) power plants is one of the most popular renewable power generation methods that is available in most parts of the world. Rising the PV cell temperature is one of the proved weak points which negatively affects their electricity production. Different ways have been proposed in order to degradation of temperature effects on PV cells. One of them, is using phase change materials (PCMs) to prevent the rapid rise of the temperature of PV modules. PCMs absorb parts of temperature of cells, which is leads to decrease the PV temperature. Several methods were presented in PV/T field based on PCMs. The main purpose of this paper is to introduce the major coolant ways of PV modules and provides a review of different methods of cooling PV modules by using PCMs. For each section, some suggestions for developing purposes have been presented.

This paper proposes a developed basic Multi-Level Inverter that is commercially suited for higher number of levels. The suggested topology can produce larger ratios of steps per DC sources, switches, gate-driver circuits and total devices than previous structures. The increased levels of suggested topology has led to low THD and better power quality. Accordingly, the output-side filter can be removed or its size can be reduced. The proposed topology doesn’t employ H-bridge to produce negative levels. So, the total voltage stress on switches is reduced in great extent. All the aforementioned properties make the suggested topology a compact, light and cheaper structure. Also, the suitability for supplying resistive-inductive (R-L) loads is another merit of suggested topology. Since the magnitude of DC sources influences the number of levels, three different scenarios have been considered for selecting magnitude of DC sources in basic topology. Then, the switching states, key parameters and blocking voltage on switches of suggested basic topology have been presented for each scenario. In the following, the generalized topology have been proposed that is consisted of cascaded basic units. Then, a generalized methodology has been suggested for selecting magnitude of DC sources in generalized topology to minimize redundant switching states and maximize number of voltage levels. To verify properties of suggested topology, it has been compared with similar novel structures. Also, to check correct performance of suggested topology, its basic version has been simulated in PSCAD/EMTDC software. The comparison and simulation outcomes certify advantages and correct operation of proposed topology.

This paper introduces a new exclusive binary search (EBS) algorithm to solve the economic dispatch problem (ED). This new algorithm converges to the best possible solution, corresponding to the precision requirements of the problem with a systematic search structure. The most essential purpose of economic dispatch is the optimal allocation of each generator's load sharing and the cost reduction of the active units in the power system. In this article, nonlinear factors and constraints are considered, including inlet steam valves’ effect, Valve-Point Effect (VPE), generation and load balances in the system, prohibited operating zones (POZs), power generation limits, ramp rates limits, and line losses. According to these constraints, the complexity of computation increases. However, the proposed algorithm will be able to find the optimal solution. This algorithm is implemented on three standardized 13, 15, and 40-unit test systems considering different operating conditions. Simulation results indicate the capability of this algorithm to solve ED problems.