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In this study, two wind-solar-based polygeneration systems namely CES-1 and CES-2 are developed, modeled, and analyzed thermodynamically. CES-1 hybridizes a heliostat based CSP system with wind turbines while CES-2 integrates heliostat-based CPVT with wind turbines. This study aims to compare the production and thermodynamics performance of two heliostat based concentrated solar power technologies when hybridized with wind turbines. The systems have been modeled to produce, freshwater, hot water, electricity, hydrogen, and cooling with different cycles/subsystems. While the overall objective of the study is to model two polygeneration systems with improved energy and exergy performances, the performances of two solar technologies are compared. The wind turbine system integrated with the comprehensive energy systems will produce 1.14 MW of electricity and it has 72.2% energy and exergy efficiency. Also, based on the same solar energy input, the performance of the heliostat integrated CPVT system (CES-2) is found to be better than that of the CSP based system (CES-1). The polygeneration thermal and exergy efficiencies for the two systems respectively are 48.08% and 31.67% for CES-1; 59.7% and 43.91% for CES-2. Also, the electric power produced by CES-2 is 280 kW higher in comparison to CES-1.

India ranked 5th in the world for using hydroelectric power production. As of 31 March 2020, India's total installed hydroelectric plant capability was 46,000 MW or 12.3% of its total electricity production capacity. Savonius water turbine is a useful prime mover to convert hydraulic power to electric power. It has been proven that the twisted blade of the blade has better performance than others. In the present study, the Numerical method has been used to analysis the 60° twist angles from top to bottom of the blade. The aspect ratio is taken as 1. Research is carried out for the variable load on the shaft for the same flow rate and twist angle. In the present numerical investigation, the considered angular velocity is 1 rad/s, 5 rad/s, 10 rad/s, 15 rad/s, 20 rad/s, 30 rad/s, 40 rad/s, 50 rad/s, 60 rad/s, 70 rad/s, 80 rad/s, 90 rad/s, 100 rad/s and 150 rad/s. The numerical analysis shows that the higher the load on the shaft, the lower the power generated by the turbine and vice-versa.

Electrical power connectors are critical points of electrical networks. Failure in high-voltage connectors may result in major power outages, safety risks and important economic consequences. Therefore, there is an imperious need to tackle such issue by developing suitable on-line condition monitoring strategies to minimize the aforementioned problems and to ease the application of predictive maintenance tasks. This work develops an on-line condition monitoring method to predict early failures in power connectors from data acquired on-line (electric current and voltage drop across the connector, and temperature) to determine the instantaneous value of the connector resistance, since it is used as a signature or indicator of its health condition. The proposed approach combines a parametric degradation model of the resistance of the connector, whose parameters are identified by means of the Markov chain Monte Carlo stochastic method, which also provides the confidence intervals of the electrical resistance. This fast approach allows an on-line diagnosis of the health condition of the connector, anticipating its failure and thus, easing the application of predictive maintenance plans. Laboratory results emulating the ageing conditions of the connectors prove the suitability and feasibility of the proposed approach, which could be applied to other power products and apparatus.

When the number of wind farms increases, the number of wind turbines placed in forested areas will also increase, this is because of the large forest areas in Sweden. When the wind turbines are placed in forested areas the fatigue loads increase drastically, so their maintenance costs increase making them less profitable. In this work clearings in forest are studied to be able to increase the electrical power generated by the wind turbines and decrease the fatigue loads to make them more profitable. The approach in this work is to use Computational Fluid Dynamics (CFD) with the Large Eddy Simulation (LES) turbulence model coupled to an aero elastic solver that solves the dynamic response of the wind turbine. Here Ryningsnas in Sweden is investigated with a homogeneous forest, the current clearing and an extended clearing. The electrical generator power was highest for the current clearing. But the fatigue loads were both higher and lower than the homogeneous forest depending on which part of the wind turbine that was investigated. The extended clearing nearly always had the lowest fatigue loads but unfortunately also the lowest electrical generator power. Further optimization of the clearings and the wind turbine locations in relation to them is needed to find the sweet spot where the fatigue loads are lower and the electrical generator power is higher.

In the electrical power system optimal power flow is a solution for power management with multi variable equality and inequality constraints. Different algorithms were used to solve the optimum power flow (OPF). This paper proposes the optimal power flow using efficient and reliable optimization technique of enhanced sine cosine algorithm (ESCA). The proposed algorithm used to solve the multi objective power flow function problems such as generating cost, losses, emission of power plant and to improve the voltage stability. In this IEEE standard 30 bus system with four different multi objective functions have been tested and results obtained by Enhanced sine cosine algorithm are compared with other evolutionary algorithms. The results show that ESCA gives better results than other techniques in terms of convergence speed and global optimal solutions.

Electric vehicle users need access to recharging services within the all-electrical driving range of their vehicles. However, public charging stations to be located on remote highways are in many cases far from the power grid, where a connection to the power grid may be impossible, costly, or impractical. This article formulates a stochastic mixed integer linear programming (MILP) planning model for energy storage and renewable energy systems to cover the energy demand of stand-alone charging stations for plug-in electric vehicles (PEVs) entirely using green energy generated by renewable energy sources (RESs). The proposed model accounts for the stochastic behavior of PEVs and RESs as well as the technical, economic, and operational characteristics of a variety of energy storage technologies. A customer satisfaction criterion is introduced to allow for a tradeoff between performance and investment costs. The proposed model can also be used for designing fully green PEV charging stations in urban and rural settings to capitalize on PEV environmental benefits by avoiding the use of fossil-fuel-generated electric power in their charging or to reduce the main grid load. A set of numerical studies have been performed in General Algebraic Modeling System (GAMS) environment to demonstrate the feasibility and effectiveness of the proposed model.

With the increasing popularity of renewable energy sources and the globally increasing electricity demand, the task of balancing the intermittent energy supply with varying demand becomes increasingly difficult. Instead of adjusting the supply, improving the demand response (DR) can be a more efficient way to optimize power balance. HVAC (heating, ventilation, and air-conditioning) systems, which operate on the demand side of power-grids, have a huge potential to improve the power balance. To assess their potential in a variable air volume (VAV) air-conditioning system with energy storage tank we introduce a demand response method that combines active cool-energy storage (ACES) with global temperature adjustment (GTA). To confirm the effectiveness of this combined ACES+GTA approach, we conduct measurements with the help of a full-scale VAV air-conditioning test setup. The experimental results are compared with a TRNSYS simulation. The measurements indicate that an energy-storing water-tank can effectively reduce the number of starts and stops for the heat pump. The simulation confirms that the ACES+GTA method can also effectively reduce the peak load of the power grid with little impact on the thermal comfort of the energy consumers. The cost-saving rate, compared to the conventional operating mode (no energy-storage during other periods), reaches 7.02% for an entire cooling season if the GTA method (with DR) is used.

In many developing countries,the use of conventional power plants to generate electricity is not meeting the increasing demands. Therefore, it has become important to find sustainable alternatives. In the present study, a solar hybrid combined cycle power plant consisting of a solar thermal plant, large-scale gas and steam turbines, and a magnetohydrodynamic generator has been investigated under oxy-fuel combustion. The performance analysis of this system under fuel pressure rate varying from 10 to 25 bar was conducted using Cycle Tempo software. The analysis of the gas and steam combined cycle shows that the net powers and the net efficiencies obtained ranged from 98 MWe to 134 MWe and 30.5% to 40%, respectively. In addition, the integration of the magnetohydrodynamic generator to the combined cycle led to an increase in the overall power from 169 MWe to 205 MWe. Moreover, it is seen that the fuel mass rate (2.81 kg/s) obtained in the gas turbine system under oxy-fuel combustion is significantly reduced when compared to conventional systems. The incorporation of solar energy and oxy-fuel combustion in the gas turbine system has increased the combustor inlet and outlet temperature and reduced the fuel consumption. From these observations, the solar hybrid system proposed in this study does not only generates electric power but also reduce the turbine exhaust fumes and CO2 emissions, which is a key factor in minimizing environment pollution.

Emissions produced by the aviation industry are currently a severe environmental threat; therefore, aviation agencies and governments have set emission targets and formulated plans to restrict emissions within the next decade. Hybrid aircraft technology is being considered to meet these targets. The importance of these technologies lies in their advancements in terms of aircraft life cycles and environmental benignity. Owing to these advancements, hybrid electric systems with more than one power source have become promising for the aviation industry, considering that the growth of air traffic is projected to double in the next decade. Hybrid technologies have given future hybrid fans and motor-fan engines potential as alternative power generators. Herein, Turboelectric Distributed Propulsion (TeDP) is discussed in terms of power distribution and power sources. The fundamentals of turbofan and turboshaft engines are presented along with their electricity-generation mechanism. TeDP is discussed from a design viewpoint, with a detailed discussion of different types of hybrid electric and turboelectric systems. Examples of proposed TeDP aircraft models and numerical modelling tools used to simulate the performance of TeDP models are reviewed. Finally, innovative turboelectric systems in which electric power savers and mechanical gear changers have been discarded for weight optimisation are presented along with other prospective models, engines, approaches, and architectures. The findings of this review indicate the knowledge gaps in the field of numerical modelling for NASA’s TeDP and its capability to increase the efficiency by up to 24% with a 50% reduction in emissions relative to those of conventional gas turbines.

Excessive consumption of fossil fuels has led to depletion of reserves and environmental crises. Therefore, turning to clean energy sources is essential. However, these energy sources are intermittent in nature and have problems meeting long-term energy demand. The option suggested by the researchers is to use hybrid energy systems. The aim of this paper is provide the conceptual configuration of a novel energy cycle based on clean energy resources. The novel energy cycle is composed of a wind turbine, solar photovoltaic field (PV), an alkaline fuel cell (AFC), a Stirling engine and an electrolyzer. Solar PV and wind turbine convert solar light energy and wind kinetic energy into electricity, respectively. Then, the generated electricity is fed to water electrolyzer. The electrolyzer decomposes water into oxygen and hydrogen gases by receiving electrical power. So the fuel cell inlets are provided. Next, the AFC converts the chemical energy contained in hydrogen into electricity during electrochemical reactions with by-product (heat). The purpose of the introduced cycle is to generate electricity and hydrogen fuel. The relationships defined for the components of the proposed cycle are novel and is examined for the first time. Results showed that the output of the introduced cycle is 10.5 kW of electricity and its electrical efficiency is 56.9%. In addition, the electrolyzer uses 9.9 kW of electricity to produce 221.3 grams per hour of hydrogen fuel. The share of the Stirling engine in the output power of the cycle is 9.85% (1033.7 W) which is obtained from the dissipated heat of the fuel cell. In addition, wind turbine is capable of generating an average of 4.1 kW of electricity. However, 238.6 kW of cycle exergy is destroyed. Two different scenarios are presented for solar field design.

The possibility of exploiting electrical energy scavenged from bicycle mechanical vibrations by piezoelectric harvesters is investigated. The bicycle vibrations on a typical city track are characterized through road tests and the power spectral densities (PSDs) of measured vibrations are presented. Both analytical and experimental methods are adopted to estimate the average electric power that can be harvested by a standard piezoelectric harvester with tip mass mounted on the bicycle. The possibility of tuning the harvester by means of liquid tip masses, resulting in a better trade-off between generated power and stress inside the piezoelectric layer, is investigated as well.

Energy harvesting in the railway industry has great potential for many applications. Energy harvesters can provide electrical power for track-side, on-board, and infrastructure instruments, including health monitoring sensors, signaling, switches, and safety equipment. Due to the rapidly growing trend of the railway network, a considerable number of instrumentations need to be located in inaccessible, remote, and harsh locations where providing the energy through cable is almost impossible. In these cases, self-powered sensors and distributed power generators can be used based on energy harvesting techniques. High-intensity sound and vibration levels in the railway environment prove them to be promising sources of energy for self-powered devices. This paper aims to provide a comprehensive review on the railway sound and vibration energy harvesting, from the beginning to the most state-of-the-art. This paper addresses different energy harvesting resources for the railway environment, diverse methods of energy harvesting and their advantages and drawbacks, and at the end, energy harvesting applications in the railway industry. Different models and prototypes of energy harvesters are introduced and compared. Finally, the potential applications of railway energy harvesting are addressed, and future challenges and trends are discussed. The scheme of the present paper is designed in a way to provide readers the most significant principles that need to be considered in the design of railway energy harvesters.

Hybrid parabolic trough concentrators were considered as the basis of co-generation systems, which mainly based on the Simultaneous production of thermal and electrical energy. In this paper, a thermal model of two cogeneration systems consisting parabolic trough collector, combined with a cylindrical thermoelectric generator was presented. The collector of the present configurations forms an annular channel between the inner side of absorber tube and upper surface of tubular thermoelectric generator. A heat transfer fluid (Therminol VP1 or hot water) is passed along the annular channel using a pump with low consumption, which mainly energized by the produced power from the tubular thermoelectric generator. Also, the heat transfer fluid (Therminol VP1 or Hot water) temperature is mainly based on the temperature adjustment principle, where the heat transfer fluid flow rate is adjusted according to sun irradiation to keep the heat transfer fluid temperature at 400 °C for Therminol VP1 or at 95 °C in the case of water. To examine the effects of solar concentration ratio and sun irradiation on the thermal and electrical performance of the hybrid system, a set of nonlinear equations were developed and coded in MATLAB software (R2015a). The power output and electrical efficiency of the tubular thermoelectric generator, the overall efficiency and net power as well as hot water storage of the hybrid systems were separately presented and discussed for all three solar concentration ratios and ten sun irradiation values. To validate the predicted results of the numerical model, two available research works have been used. The comparison of results obtained with results of the exact solution indicates a good agreement. The novel integration technique shows major improvements in thermal and electrical performance of both hybrid systems. As a results, the overall efficiency of the first hybrid system (Here, Therminol VP1 serves as a heat transfer fluid) reached to 70.550% corresponding to 306.5826 L/Day of Therminol VP1 at 400 °C and about 585 W of additional power. These values in the case of water serves as a heat transfer fluid up to 76.913%, 1058.467 L/D of hot water at 95 °C and 97.032 W of additional electrical power, respectively.

This paper demonstrates the analysis of a long-distance high-power microwave wireless power transmission (MWPT) system based on asymmetrical resonant magnetron and cyclotron-wave rectifier. In the system, the novel magnetron with the asymmetrical resonant cavity, the straps, and the output loop coupling circuit can effectively promote the beam–wave interaction, suppress the mode competition, and enhance the output coupling, which results in a 400 kW output microwave power with a conversion efficiency of 45%. The transceiver Cassegrain antenna system with its simple structure, high conversion efficiency, and high power capacity can attain an integral power transmission efficiency of 2.6% at 10 km distance. The cyclotron-wave rectifier with high efficiency and single-tube high power capacity can achieve 85% microwave to DC conversion efficiency. Finally, the long-distance high-power MWPT system can achieve 8.5 kW DC power with about 1% DC–DC transmission efficiency at the operating 2.45 GHz frequency and for the 10 km distance. Such a system is likely a potential and attracting solution to remotely power the fuel-free aerial vehicle from the ground, can also provide electrical power to an isolated mountain top or an island, and even an alternative to transmit the power from space solar power satellite in geostationary orbit to the ground.

Lessons learned from the Fukushima Daiichi nuclear power plant accident directed that multiple failures should be considered more seriously rather than single failure in the licensing bases and safety cases because attempts to take accident management measures could be unsuccessful under the high radiation environment aggravated by multiple failures, such as complete loss of electric power, uncontrollable loss of coolant inventory, failure of essential safety function recovery. In the case of the complete loss of electric power called station blackout (SBO), if there is no mitigation action for recovering safety functions, the reactor core would be overheated, and severe fuel damage could be anticipated due to the failure of the active heat sink. In such a transient condition at CANDU-6 plants, the seal failure of the primary heat transport (PHT) pumps can facilitate a consequent increase in the fuel sheath temperature and eventually lead to degradation of the fuel integrity. Therefore, it is necessary to specify the regulatory guidelines for multiple failures on a licensing basis so that licensees should prepare the accident management measures to prevent or mitigate accident conditions. In order to explore the efficiency of implementing accident management strategies for CANDU-6 plants, this study proposed a realistic accident analysis approach on the SBO transient with multiple-failure sequences such as seal failure of PHT pumps without operator's recovery actions. In this regard, a comparative study for two PHT pump seal failure modes with and without coolant seal leakage was conducted using a best-estimate code to precisely investigate the behaviors of thermal-hydraulic parameters during transient conditions. Moreover, a sensitivity analysis for different PHT pump seal leakage rates was also carried out to examine the effect of leakage rate on the system responses. This study is expected to provide the technical bases to the accident management strategy for unmitigated transient conditions with multiple failures.

This communication presents the implementation of a central receiver where helically coiled tubes are employed in order to enhance the rate of solar to heat conversion, which is the energy source that drives a cogeneration cycle which consists of organic Rankine cycle and the ejector-absorption refrigeration cycle. A numerical simulation with the application of computational fluid dynamics using the ANSYS-FLUENT package was conducted to examine the effect of the coil diameter and inlet oil (Duratherm 600) temperature on the pressure and temperature of solar heat transfer fluid (SHTF) which leaves the receiver. It is found that for inlet temperature of 92°C and direct normal irradiations of 850 W/m2, the outlet temperature of solar heat transfer fluid is raised by 9% when the coil diameter increased from 150 to 400 mm. Further, cogeneration cycle response to altering operating parameters is also investigated. From 100% radiative solar energy supplied to cogeneration cycle, it is revealed that fluids of organic Rankine cycle; R141b, R600a, and R143a produce the energetic output as 20.64%, 15.04%, and 8.33%, respectively, and the remaining solar input energy is lost to environment through temperature difference. The exergy distribution shows that for R141b operated cycle out of 100% solar exergy, 16.79% is produced as exergetic output, 81.94% is the exergy destroyed, and the remaining 1.27% is the exergy loss.

Life Cycle Climate Performance (LCCP) is a widely accepted metric to evaluate the carbon footprint of air conditioning (AC) systems “from cradle to grave.” This paper: (1) reviews the invention and evolution of LCCP, including a comprehensive timeline and bibliography; (2) documents the successful application of LCCP in the replacement of HFC-410A with HFC-32 in room air conditioners; (3) compares the conceptual frameworks and the operational approaches; and 4) reflects on the drawbacks of current LCCP research and points out possible future work. The major policy-relevant findings are: 1. The indirect emissions caused by energy consumption is 70 to 80 percent of the LCCP of AC systems in most countries but will decline in importance as electric power supply shifts rapidly from fossil fuel to renewable energy sources, which have near-zero carbon intensity; 2. The embodied greenhouse gas (GHG) emissions in refrigerant manufacture are, in most cases, negligible but the physical and chemical properties are crucial for system optimization for low carbon footprint; 3. The LCCP metric can be used for multiple purposes such as refrigerant selection and AC system architecture optimization; and 4. Data limitations in material manufacturing and the carbon intensity of electric power are the most significant challenges. Finally, this paper describes a variety of methods to fill in data gaps, including the correction factor method, the data-driven method, and the database searching method. The next-generation LCCP will be an enhanced evaluation process considering local climate, heat islands, and local power supply characteristics.

Solar-based power and desalination system using super-critical carbon dioxide (S–CO2) Brayton cycle can be considered as one of the most promising development directions of future energy. This study presents the design and behaviour estimate of a novel concentrated solar-driven power and desalination (CSPD) system using S–CO2 Brayton cycle and multi-stage flash (MSF) desalination technology. Operation simulations and exergic analysis of the CSPD system are conducted by utilizing the Ebsilon software. Operation behaviour estimate results of the CSPD system show that the efficiency of S–CO2 Brayton cycle is 36.6%. The electric power and freshwater daily output of the CSPD system are 50.1 MW and 4050.8 t. The CSPD system can perform the solar-driven electricity production and solar-driven desalination simultaneously according to the pre-set operation strategy. The exergic analysis results indicate that the solar tower receiver and heat exchanger of desalination system have the two maximum energy destructions as well as the two lowest exergy efficiencies. The economic analysis results reveal that the CSPD system has an equivalent LCOE (levelized cost of electricity) of 0.059 $∙kWh−1 and an LCOW (levelized cost of water) of 1.15 $∙t−1, which means the CSPD system is economically feasible.

Ice accretion on the wings seriously threatens the flight safety of an aircraft. From the perspectives of ensuring flight safety and saving power consumption, the ice shape modulation method using distributed plasma is proposed. Distributed plasma actuator units are designed to modulate the spanwise continuous ice at the leading edge into periodically segmented ice pieces, forming a wavy leading edge. Both airfoil and scaled aircraft model, with continuous and modulated ice, are experimentally investigated and simulated. Compared with the continuous ice, ice shape modulation can significantly improve the aerodynamic performance, flight control characteristics and flight safety. This method can save about half electric power, which is very beneficial for application.

Osmotic heat engine (OHE) is a promising technology to harvest low-grade heat from renewable energy source. In previous studies of OHEs, the features of actual heat source and application scenarios are usually ignored. Here we present an advanced adsorption-based osmotic heat engine to harvest solar energy and a dynamic model for such energy utilization system is established. Firstly, the dynamic characteristics of the OHE from transient to cyclic-steady state is investigated. There exist an optimal adsorption/desorption time to maximize the electric power and efficiency simultaneously. Higher working concentration elevates the electric power and efficiency. Larger direct solar irradiation intensity upgrades the electric power while hinders the efficiency. Then a practical simulation of a small sized OHE harvesting solar energy to generate electricity during a day is carried out and the effects of some important parameters on the system under transient state are analyzed. The results indicate that there is a best number of cycles the system performs during a day to maximize the average electric power and efficiency. Among the ten selected adsorbents, MIL-101 leads to the largest average electric power of 41.8 W and Zeolite 13X leads to the highest electric efficiency of 1.04% when the number of cycles is set as 60 and 7 mol/kg NaCl is employed as working solution.

Controllable rapid expansion and activation of gases is important for a variety of applications, including combustion engines, thrusters, actuators, catalysis, and sensors. Typically, the activation of macroscopic gas volumes is based on ultra-fast chemical reactions, which require fuel and are irreversible. An “electrically powered explosion”, i.e., the rapid increase in temperature of a macroscopic relevant gas volume induced by an electrical power pulse, is a feasible repeatable and clean alternative, providing adaptable non-chemical power on demand. Till now, the fundamental problem was to find an efficient transducer material that converts electrical energy into an immediate temperature increase of a sufficient gas volume. To overcome these limitations, we developed electrically powered repeatable air explosions (EPRAE) based on free-standing graphene layers of nanoscale thickness in the form of microtubes that are interconnected to a macroscopic framework. These low-density and highly permeable graphene foams are characterized by heat capacities comparable to air. The EPRAE process facilitates cyclic heating of cm3-sized air volumes to several 100 °C for more than 100,000 cycles, heating rates beyond 300,000 K s−1 and repetition rates of several Hz. It enables pneumatic actuators with the highest observed output power densities (>40 kW kg−1) and strains ∼100%, as well as tunable microfluidic pumps, gas flowmeters, thermophones, and micro-thrusters.

International audience; This paper proposes a new framework for the operational reliability evaluation of integrated electric power-gas networks (IEPGNs). First, a novel approach for modeling the failure modes of natural gas pipelines is presented. This approach utilizes the concept of virtual nodes and employs a gas release rate model to consider the pinhole, hole, and rupture failure modes of pipelines. Thereafter, a four-state Markov model for natural gas-fired generators (NGFGs) with dual-fuel capabilities is proposed. The area risk method is extended to include the proposed reliability models, and the partial reliability indices of the area risk method are evaluated using a non-sequential Monte Carlo simulation (NSMCS). A nonlinear optimization model is also proposed to calculate electric and gas load curtailments for each system state in NSMCS. This model is linearized to obtain a mixed-integer linear programming (MILP) model for reducing the computational burden. The computational performance of NSMCS is further improved by adopting cross entropy (CE)-based importance sampling (IS). Finally, the efficacy of the proposed framework is demonstrated on three test systems. Case studies validate the importance of considering the proposed reliability models of IEPGNs for operational reliability evaluation. The impacts of operational strategies on the operational reliability indices are also demonstrated.

Stochastic nature of load demand has a great impact on the performance of electrical power system. As a result, planning of electrical power system considering load uncertainties became inevitable. This paper presents Monte Carlo simulation based different bio-inspired algorithms, grey wolf optimization (GWO), manta ray foraging optimization (MRFO), satin bower bird optimization (SBO) and whale optimization (WOA) to optimize locations of three DG units under load uncertainties considering 500 scenarios. Each scenario includes 50 iterations which means that for each run we have 25,000 iterations and 500 characteristics for different load value. Two objectives are achieved. Firstly, statistically finding the optimal probabilistic location of three DG units under load uncertainties in IEEE 33-bus and IEEE 69-bus radial distribution system based on Monte Carlo simulation integrated with different bio-inspired algorithms. Secondly, comparing between the performances of four different bio-inspired algorithms. Three objective functions are considered, minimizing active power loss, minimizing voltage deviation and maximizing voltage stability index. The active and reactive power demand are normally distributed using normal distribution function. The optimal probabilistic location is investigated considering two cases under load uncertainties, optimizing location of three DG units generally and optimizing location of one DG unit assuming two optimum locations for the other two units extracted from case I. The obtained results (after placing DG units) are compared to the base case (DG units are not connected) and compared to each other according to the optimization technique. The results show that, SBO algorithm superiors other algorithms almost in all cases. Comes next GWO which provide good results generally. However, the good performance obtained by MRFO, it consumes twice the time of other algorithms. WOA however fast convergence, it provides results worse than other algorithms. The system is applied to the well-known IEEE 33-bus and IEEE 69-bus radial distribution system.

This paper provides an overview of hyperloop technologies, including a brief discussion of key components of a hyperloop system that determine the electric power requirements as a function of time. At-scale hyperloop systems do not yet exist, so a model was used to generate a set of load profiles for conceptual hyperloop realizations at four locations in the United States: two systems in California and one each in Colorado and Ohio. In all four cases, the modeled hyperloop load profiles included pulses in both active and reactive power. Grid modeling was performed to estimate the grid impacts and for discussing grid integration challenges. The paper discusses how energy storage systems might be used to eliminate the pulsating load characteristics or significantly reduce it to accommodate current grid planning guidelines.

Sonochemistry is considered as one of the cleaner pathways for hydrogen production. The present paper investigates the potential of this technique based upon mass, mass to energy and energy conversion metrics, using modelling and experimental approaches. Four scenarios are examined assuming four saturating gases, namely O2, air, N2 and Ar, four acoustic frequencies, i.e., 20, 210, 326 and 488 kHz, and considering common acoustic intensities then common net electric power. The study revealed that Ar is the best fitting saturating gas for the sonochemical production of hydrogen. With a common acoustic intensity of 0.48 W/cm2, an optimum ratio of H2 molar yield to acoustic energy intensity is retrieved at 210 kHz, while with a common net electric power of 87 W, the highest ratio of hydrogen yield to electric energy was observed at 20 kHz. Results were interpreted based upon emitter surface, energy conversion and distinction of calorimetric and cavitational energies.

Space systems require technologies intended for power generation and management most of the time. Within the Electric Power Subsystem, one or a group of several batteries conform the secondary power source of a space mission. In this work, the initial design of a Li-ion battery for small spacecraft, based on Commercial Off-The-Shelf (COTS) cells, is shown, the evolution of this design being thoroughly described from the first configuration. This battery has been sized to satisfy the power requirements of the UNION/Lian-He mission, the third Low Earth Orbit (LEO) microsatellite completely designed within an academic environment by the staff of Instituto Universitario de Microgravedad “Ignacio Da Riva” (IDR/UPM). Structural analyses of different battery configurations were carried out via Finite Element Method (FEM) modeling, in order to assure the viability of the design. The final configuration of the battery was reached based on these studies, which are described in the present work.

This paper presents the results of an experimental study evaluating R450A as a possible drop-in replacement for R134a in household heat pump tumble dryers. A heat pump installed in a tumble dryer was equipped with pressure and temperature sensors, and electrical power meters. First, the energy consumption according to the IEC 61121 standard was evaluated using R134a. Then the refrigerant was replaced with R450A and a new optimal charge was determined. The tumble dryer performance was then evaluated again and compared with the previous results. It was found that R450A is a suitable drop-in replacement for R134a in heat pump tumble dryers. The total energy consumption of the tumble dryer decreased by 3.7% and several other benefits such as a better utilized evaporator, and a lower refrigerant temperature at the compressor outlet were observed. Additionally, the refrigerant charge CO2 equivalent was reduced by more than 50%. However, the duration of the drying cycle increased by 4.2%, due to a slightly lower condensing temperature in the heat pump.

The organization of operation, maintenance and repair of the basic technological facilities of electric power systems (EPS), which are beyond their designed service life (hereinafter referred to as ageing facilities, or AFs) is one of the problems that determine the energy security of many countries, including economically developed nations. The principal cause of insufficient overall performance of AFs is the traditional focus of the EPS management on economic efficiency and the insufficient attention to reliability and safety of AFs. The tendency to nonlinear growth in the frequency of occurrence of unacceptable consequences in the EPS requires ensuring the operational reliability and safety of AFs. The averaged estimates of reliability and safety used at designing power facilities are not suitable for characterization of overall operational performance. Among the basic and the least investigated (in terms of operational reliability and safety) EPS facilities are overhead power transmission lines (OPL) with a voltage of 110 кV and above. This is for a reason. OPL are electric power facilities with elements distributed along a multi-kilometer line (supports, insulators, wires, accessories, etc.). That is what makes the organization of continuous monitoring of the technical condition of each of these elements, and, consequently, the assessment of operational reliability and safety, so problematic. A method is suggested for assessment of “weak links” among the operated OPL on operative intervals of time along with a method for assessment of the technical condition of OPL at examination of a representative sample.

The role of nanodielectrics in the electrical power system is becoming crucial owing to its superior properties and potential applications in the field. Yet, the materials face limited breakdown strength and thermal properties. Further, the nanodielectrics have not found a comprehensive commercial platform because of the costly manufacturing process, and characterization and testing facilities. Therefore, to reduce the involved cost, in this work, an FE (finite element) based computational technique has been implemented to visualize the effect of shape, size, and filler concentration under the application of high voltage (HV). The epoxy-based nanodielectrics have been modeled incorporating a range of different shapes and size nanofillers—Al2O3, BN, BeO, SiO2, and TiO2. The paper discusses the 2D-analysis of the modeled nanodielectric in the steady-state electrostatic fields and thermal domains. It shows the insights of the nanofillers’ choice to ensure a perfect blend of electrical and thermal properties. The epoxy with square-shaped BeO fillers showed a rise in the electric field of nearly 1.5 times than unfilled neat epoxy, which indicates a significant surge in thermal conductivity at specific filler loading.

Increasing demand for commercial air travel is projected to have additional environmental impact through increased emissions from fuel burn. This has necessitated the improvement of aircraft propulsion technologies and proposal of new concepts to mitigate this impact. The hybrid-electric aircraft propulsion system has been identified as a potential method to achieve this improvement. However, there are many challenges to overcome. One such challenges is the combination of electrical power sources and the best strategy to manage the power available in the propulsion system. Earlier methods reviewed did not quantify the mass and efficiency penalties incurred by each method, especially at system level. This work compares three power management approaches on the basis of feasibility, mass and efficiency. The focus is on voltage synchronisation and adaptation to the load rating. The three methods are the regulated rectification, the generator field flux variation and the buck-boost. This comparison was made using the propulsion system of the propulsive fuselage aircraft concept as the reference electrical configuration. Based on the findings, the generator field flux variation approach appeared to be the most promising, based on a balance of feasibility, mass and efficiency, for a 2.6MW system.

THE PURPOSE. To describe the use of ABC and HML-methods for predicting the volume of emergency stock for main electrical equipment accessory parts. To describe the content of the methods, consider the problems and complexity of use. To propose an algorithm constructing a new method for forming an emergency stock based on the statistical data of an electric power company. METHODS. Various practical tasks can arise in electric power company. We have determined the most effective method for solving them using a numerical experiment. The highest efficiency of the ABC method is shown. The results of statistical processing will help to improve forecast precision using the ABC-method. RESULTS. The complex of statistical data and ABC-analysis showed high efficiency in short-term forecasting of electrical equipment components emergency stocks. Authors found that HML-analysis provides less precision in predicting the requirement of equipment. CONCLUSION. The ABC method is the most promising for implementation the specific task. The use of the method helps to accurately predict emergency stocks of company electrical equipment. The HML-method does not allow to precision planing the amount of required equipment.

This paper investigates the effect of the load factor of frequency converters and thyristor converters on electrical power quality. Recommendations for reducing the influence of higher harmonics and switching overvoltages on the characteristics of electrical power are provided. Higher harmonics were measured by a PKK57 complex device for controlling electrical parameters and a digital oscilloscope of the Tektronix TDS 2024V type. Impulse switching overvoltages were recorded by an active resistance divider of the DNEK-10 type and the above-mentioned oscilloscope. The obtained data were processed by the Loginom 6.4 software and the methods of mathematical statistics. The lower threshold level of the load factor of frequency converters and thyristor converters was set equal to 0.8, at which the sinusoidal distortion of voltage curves correspond to the RF standard of electrical power quality. The suppression degree of higher harmonics from the 5th to 17th frequency by power transformers with a capacity of 250–6,300 kV. A ranged from 95 to 45%. The use of the ‘transformer–converter–electric receiver’ system as applied to the power supply systems of mining and processing enterprises was substantiated. It was shown that electric motors with a capacity of up to 2,500 kW inclusively require protection against switching overvoltages. Conventional RC-absorbers based on RC-circuits connected to the terminals of electric motors are shown to be highly efficient for protecting electric motors against switching overvoltages. Thus, the quality of electrical power in power supply systems of mining and processing enterprises in Russia can be ensured by frequency converters and thyristor converters with a load factor of 0.8 or greater. Provided that the transformer capacity does not exceed 1,000 kV. A, a more efficient and less expensive ‘transformer–converter–electrical receiver’ system is recommended. Effective protection of electric motors of up to 2,500 kW inclusive can be provided using the proposed conventional RC absorber, which maintains the overvoltage rate at a level not exceeding 1.7.

The air compressor is a key component in the polymer electrolyte membrane (PEM) fuel cell system and its performance has great impact on the electric power output from the system. Here, analysis was conducted firstly on the Roots-type compressor with fixed internal compression based on the volume reduction created by helical rotors. The built-in volume ratio variations with the wrap angle and the lobe numbers were calculated and discussed. Then a prototype of the Roots-type air compressor with 6 lobes was developed according to the outcomes of the research. The volumetric and isentropic efficiency of the prototype were measured under the discharge pressures from 0.11 MPa to 0.25 MPa while the rotation speeds from 10000 to 14000 rpm. Under the design conditions, the volumetric efficiency and isentropic efficiency of the Roots-type air compressor were 75.8% and 53.9% respectively. It was concluded that this kind of Roots-type air compressor is especially suitable for the fuel cell systems applied in the range extended electric vehicles.

This paper investigates the small-signal power oscillations in a VSC-based multi-terminal DC (MTDC) power transmission system. Regarding the DC power oscillation modes (DPOMs), this paper demonstrates that when the master–slave control is adopted for the MTDC power system, there is only one DPOM. In contrast, when the DC voltage droop control is adopted, the DC electric power oscillations (DEPOs) may be multi-modal oscillations as there are multiple DPOMs. Furthermore, a better understanding of DEPOs, which is analogous to low-frequency electric power oscillations (LEPOs) in conventional AC power systems, is obtained, unveiling how the DPOMs determine the power oscillations in AC and MTDC power systems. Moreover, this paper theoretically verifies that the DPOMs determine the behaviors of both DEPOs in MTDC systems and power oscillations between the VSCs (which adopt the DC voltage control or DC voltage droop control) and external AC systems. By analogy to LEPOs, damping torque analysis is applied to examine the stability risk of the MTDC power system. The results indicate that even if VSCs are self-stable, there is a potential risk of growing DEPOs occurring in MTDC power systems under heavy DC loads.

The effective use of the available land in a PV power plant can be obtained by the integration of a commonly available flat stainless-steel reflector. The integration of the reflector increases module temperature and simultaneously the degradation rate. In this regard, the present work proposes a 3-D opto-thermal simulation model to analysis the performance of the commercial C-Si PV module with stainless steel (SS) reflector. The study also highlights that the natural flow of wind effectively reduces the elevated temperature and the direction of wind flow plays a very prominent role in heat evacuation. Incidentally, the largest state of India, Rajasthan has plenty of promising light breeze throughout the year and that is to come from the mostly north or west direction. A simpler version of the proposed model was experimentally validated in the month of July in Jaipur, India. The simulation result shows that the reflector induces 30 °C to 40 °C increment in temperature in the PV module for laminar airflow. Considering the turbulent airflow model, the temperature rise is 10–20 °C. The thermal scenario largely depends on wind flow and the season considered. The lifetime of the PV module is reduced from 25 years to 21 years with the integration of reflector at favorable wind flow condition. However, it generates a significantly more electric power which overcomes the lifetime loss.

A solid oxide cell-based energy system is proposed for a solar-powered stand-alone building. The system is comprised of a 5 kWel solid oxide fuel cell (SOFC), a 9.5 kWel solid oxide electrolysis cell (SOEC), and the required balance of plant. The SOFC supplies: 1- building demand in the absence of sufficient solar power, 2- heat for SOEC in endothermic and standby modes. Thermal integration of SOFC and SOEC is implemented through a network of heat exchangers, combined with set of control algorithms. Two control strategies were implemented to actuate the SOFC in response to endothermic heat demands of SOEC by manipulating: 1- electric power, 2- fuel utilization. The results of dynamic simulation of system for two scenarios (sunny day and cloudy day) showed successful compliance of temperature constraints with both methods. Manipulation of fuel utilization, however, resulted in better system performance in terms of efficiency and H2 balance.

All-wheel-drive (AWD) multimotor electric powertrains offer greater potential for system performance, efficiency, and reliability improvements. In this article, a new AWD electric powertrain that can increase the overall powertrain efficiency and battery lifetime is introduced. The proposed powertrain is based on a compact and efficient flywheel-based kinetic energy recovery system (KERS) that overcomes most of the shortcomings of the conventional electric KERS. Here, a significant part of the mechanical power transfer takes place without conversion to electrical power. Therefore, a selectable fraction of the recoverable kinetic energy is processed by power electronics. Thus, no energy exchange is necessary between the battery and the powertrain during acceleration and deceleration, resulting in a reduced battery power rating. This article compares the proposed powertrain with a conventional AWD electric powertrain. Mathematical modeling and simulations based on the space vector method were used for both powertrains that show the advantage of the proposed powertrain over the conventional one. The experimental data are also presented from our proof of the concept laboratory setup.

Numerical simulation is the key technique for large-scale power system analysis. Redistribution of global renewable power via international interconnections requires new simulation tools to study the interconnected systems with different nominal frequencies as a whole. This paper introduces an open-source simulation toolkit for electrical power systems (STEPS) hosted at Github. Its kernel is coded in C++ with major functions of power flow and electro-mechanical dynamic simulation. Flexible options are provided and configurable to improve power flow solution and dynamic simulation. Common devices and models are supported in STEPS for AC/DC hybrid system studies. The study of interconnected systems with different nominal frequencies is supported in STEPS for research of international interconnection. Application program interfaces are provided and wrapped with Python to enable high-level interfaces for general applications. STEPS is thread-safe, and parallel computation is supported in both kernel-level and task-level parallelization to accelerate simulation. It is portable and works on Windows and GNU/Linux platforms. Cases from small to large-scale systems are thoroughly tested to validate the toolkit with commercial packages as benchmarks.

The efforts to reduce the impact of the electric power generation from fossil fuels have been conducted to increase renewable energy sources and the trend to implement a decentralised scheme by distributed generation systems. However, small power plants' use does not contribute to the frequency regulation in the electrical power system due to the lack of the inertia and damping properties of synchronous generators used conventionally. This condition can produce unpredictable and unstable operational conditions of multi-area power systems. Hence, this paper aims to assess a voltage source converter (VSC) controlled by a synchronverter to help in frequency regulation in power networks that contain an actual number of renewable sources connected. The contribution lies in using the synchronverter as a control element capable of interacting correctly in a power network with a distributed generation system integrated with synchronous generators and renewable energy sources. Under this scenario, a hardware-in-the-loop (HIL) strategy of a photovoltaic-fuel cell-battery power generation system demonstrates that the VSC controlled by a synchronverter can react adequately under frequency deviations. A three power plants' performance, a conventional one and two photovoltaic (P.V.) farms handled by a synchronverter tied through a transmission link, is studied to demonstrate that the frequency viewpoint's behaviour and control purposes are satisfied. The results show the viability of the synchronverter as a frequency control strategy in electrical networks.

This paper investigates the performance of a hydrogen refueling system that consists of a polymer electrolyte membrane electrolyzer integrated with photovoltaic arrays, and an electrochemical compressor to increase the hydrogen pressure. The energetic and exergetic performance of the hydrogen refueling station is analyzed at different working conditions. The exergy cost of hydrogen production is studied in three different case scenarios; that consist of i) off-grid station with the photovoltaic system and a battery bank to supply the required electric power, ii) on-grid station but the required power is supplied by the electric grid only when solar energy is not available and iii) on-grid station without energy storage. The efficiency of the station significantly increases when the electric grid empowers the system. The maximum energy and exergy efficiencies of the photovoltaic system at solar irradiation of 850 W m-2 are 13.57% and 14.51%, respectively. The exergy cost of hydrogen production in the on-grid station with energy storage is almost 30% higher than the off-grid station. Moreover, the exergy cost of hydrogen in the on-grid station without energy storage is almost 4 times higher than the off-grid station and the energy and exergy efficiencies are considerably higher.

With the advent of the advanced metering infrastructure, electricity usage data is being continuously generated at large volumes by smart meters vastly deployed across the modern power grid. Electric power utility companies and third party entities such as smart home management solution providers gain significant insights into these datasets via machine learning (ML) models. These are then utilized to perform active/passive power demand management that fosters economical and sustainable electricity usage. Although ML models are powerful, these remain vulnerable to adversarial attacks. A novel stealthy black-box attack construction model is proposed that targets deep learning models utilized to perform non-intrusive load monitoring based on smart meter data. These attacks are practical as there is no assumption of the knowledge of training data, internal parameters, and architecture of the targeted ML model. The profound impact of the proposed stealthy attack constructions on energy analytics and decision-making processes is shown through comprehensive theoretical, practical, and comparative analysis. This work sheds light on vulnerabilities of ML models in the smart grid context and provides valuable insights for securely accommodating increasing prevalence of artificial intelligence in the modern power grid.

Due to the widespread use of copper wires in electrical power transmission, the need for raw materials with a homogeneous structure and high strength while maintaining their conductive properties is of high importance. The present study investigates the production of copper wire with improved mechanical properties and homogeneous microstructure due to its nanometre-sized structure. Therefore, the commercial pure copper specimens were subjected to severe plastic deformation (SPD) by means of equal channel angular pressing (ECAP) during four steps at ambient temperature. Due to the creation of a structure with elongated grains in the ECAP process, the deformed specimens were subjected to the direct extrusion operations; thus, a more homogeneous structure was created in them due to the appearance of a secondary radial strain. The obtained results indicate that by applying the simultaneous effects of SPD and direct extrusion on the microstructure, the mechanical properties such as strength and hardness have improved significantly, while the electrical conductivity of pure copper decreased slightly. The outcome can be used as an alternative to current methods for producing high-strength copper wires with suitable electrical conductivity properties.

Features of the electric power market functioning, in comparison with common properties of modern markets, are considered. It is shown that continuous reforms, which take place in many countries, are far from reaching effective solution. Sectoral peculiarities, connected with both technological complexity of the field and economic specificity of the market participants, form very special model of the market. The main way to increase effectivity of the market, to make it more competitive and, in the same time, socially responsible, is to use widely and deeply the modern information technologies, including technologies of artificial intelligence. A technological scheme (especially targeted on features of the electric power market) has been proposed in the article. First, the technologies merge methods of collection, storage, processing, and presentation of information. The collection of market data should be automated, particularly, by the so-called intellectual avatars, which operate in the market as virtual agents. A reliable distributed storage of data, based on blockchain technology, is chosen. The big data technologies of data structuring, storage, and processing are involved. Datamining methods include effective presentation of results in forms of graphs and diagrams. The second set of technologies includes core mathematical models and “digital twins.” They are aimed for data interpolation and extrapolation, in particular, for prediction of further system dynamics. The used neural networks have option of self-learning and self-development. At last, the third set is a set of user interfaces, which provides market actors by complete and adopted information and is organized in accordance with ideas of ergonomics.

Excellent thermal performance and simple construction are the most attractive superiorities of ammonia-salt absorption refrigeration cycles, which is considered to be potentially used in waste heat recovery for the air-conditioning and freezing applications. In the present work, an experimental prototype of an exhaust-heat-driven NH3-NaSCN absorption refrigeration system was designed and built to evaluate the performance. The prototype was designed to be constructed by commonly used devices for the purpose of cost reduction and easy manufacture. A finned-tube generator was specially designed for the exhaust-gas heat sources. The heat source from the exhaust simulation unit was supplied to the generator at temperatures between 150°C and 350°C. Experiments with variational operating conditions, such as exhaust-gas temperatures, cooling-water temperatures, chilled-water temperatures, have been conducted for varying parameters. The results showed that the minimum evaporating temperature of the prototype decreased to -24.56°C; the cooling capacity produced by the prototype was ranging from 0.748 kW to 5.60 kW. The maximum coefficient of performance based on electrical power was 17.58, and the overall coefficient of performance based on both electrical power and thermal energy varied between 0.351 and 0.653. The prototype showed satisfactory performance under wide operating conditions, indicating that the system is appropriate for both air-conditioning and freezing applications. The present study provides significant references for the optimization and application of the exhaust-heat-driven ammonia-salt absorption refrigeration systems.

Microgrids are seen as an emerging solution to locally provide clean energy. Power electronic-based distributed generators (DGs) operating in parallel are the main constituents of these systems, which extract, control, and convert electric power from renewable sources. Broadly, the approaches for controlling these systems are categorized under centralized, decentralized, and distributed strategies. Under the decentralized category, droop control and several variants of the same have been proposed in the literature over the years. A large portion of the work reported, considers linear loads. This article compares the performance of four commonly employed droop control techniques for inverter-based distributed generators, for their performance under nonlinear loading conditions and during plug and play functionality in the islanded mode of operation. The work attempts to investigate the performance of these strategies under both uniform (i.e., same control structure in the DGs) and nonuniform (DGs operating with different control structures) scenarios from the perspective of output power sharing and transients during the plug and play functionality. The evaluation is carried out through simulations of cases with constant impedance, constant current, and dynamic nonlinear loads on the modified 13-bus system using MATLAB–Simulink, and experiments on a laboratory scale microgrid.

Accurate and credible ultra-short-term photovoltaic (PV) power production prediction is very important in short-term resource planning, electric power dispatching, and operational security for the solar power system. This study proposes a novel approach of using genetically optimized non-linear auto-regressive recurrent neural networks (NARX) for ultra-short-term forecasting of PV power output. Hence, the high prediction accuracy of static multi-layered perceptron neural networks can be extended to dynamic (time-series) models with a more stable learning process. Exogenous models with different commonly available meteorological input parameters are developed and tested at five different locations in Algeria and Australia, as case studies of the arid desert climate. The prediction capabilities of the models are quantified as functions of the forecasting horizon (5, 15, 30, and 60 min) and the number of meteorological inputs using various statistical measures. It was found that the proposed models offer very good estimates of output power, with relative root mean square errors ranging between ∼10 and ∼20% and coefficients of determination higher than 91%, while improving the accuracy of corresponding endogenous models by up to 22.3% by only considering the day number and local time as external variables. Unlike the persistent model, the proposed NARX-GA models perform better as the forecasting horizon narrows down, with improvements of up to 58.4%.

This paper introduces a new HT-type module for both symmetrical and asymmetrical multilevel inverters (MLIs) with reduced power electric components. The proposed module comprises of two back to back T-type inverters connected with four cross-connected switches. This MLI addresses two major drawbacks associated with the conventional and other recently proposed MLIs which are the high voltage stress of switches and higher power component counts. The structure of the proposed device is designed combining the beneficial features of both T-type inverter and cross-switched inverter. The 1st feature allows the module to produce negative voltage levels deprived of any extra H-bridge circuit and thus decreasing the overall voltage stress significantly. The latter feature allows the device to utilize reduced number of switches to produce higher voltage levels. A comprehensive comparative analysis is additionally established between other MLI topologies to confirm the superiority of the HT-type MLI. From this analysis, it is found that the proposed MLI has successfully overcome the issues associated with other MLIs, it was able to produce the results following industrial standards and it outperformed other MLIs in different aspects such as power components count, cost, efficiency and dynamic performance. Selective harmonic elimination pulse width modulation (SHE-PWM) and nearest level control (NLC) algorithm is considered in this manuscript to generate the output results from the proposed HT-type module. All the details about the operating principle and modulation techniques utilized for the proposed MLI module are stated and validated by both simulation and experimental results.

This paper presents a low concentrating photovoltaic/thermal (LCPV/T) collector with thermoelectric generator (TEG) which is connected in series. LCPV/T produces heat and electricity while TEG transforms low-grade heat which is gained from LCPV/T into high-grade electricity. In this paper, the mathematical model is built, and the test rig is established to validity the numerical model. The performance of the proposed system under different ambient conditions is studied by test rig with biaxial tracking system. Besides, the effects of environmental parameters, the economic analysis and energy saving of the system in different seasons are also analyzed. The study result shows that the PV/T collector produces the maximum temperature of domestic hot water about 52.96 °C and a daily average electric power of 436.13W with daily average electrical efficiency of 14.34% in summer. By using the TEG module, another 1.68W (2.85‰ of the 436.13W) is generated in summer. In addition, the performance between LCPV/T in series and in parallel is researched. Moreover, the system have the potential of reducing the use of primary energy.

It is an open question whether or not the sharing economy model—utilizing unused for-profit private resources by sharing them for public use through a digital intermediary—could be adopted for public utility and service delivery in the developing world. This article addresses the question using the electric power sector in India as a case study. Six major components of the sharing economy are taken up for analysis: suppliers/service providers; infrastructure facilities; customers; public policy/regulations; platform; and pricing structure. This article discusses the status, challenges, and possible future directions.