Electricity Production System Research Articles

Optimization of an Organic Rankine Cycle–Vapor Compression Cycle System for Electricity and Cooling Production from Low-Grade Waste Heat

Optimization of an Organic Rankine Cycle–Vapor Compression Cycle System for Electricity and Cooling Production from Low-Grade Waste Heat

Economic and technical optimization of a tri-generation setup integrating a partial evaporation Rankine cycle with an ejector-based refrigeration system using different solar collectors

Three collector types, namely parabolic trough solar collector (PTSC), linear Fresnel collector (LFC), and dish collector, are employed to drive a tri-generation configuration composed of a partial evaporation Rankine cycle (PERC), a hot water production unit (HWPU), and a cascade ejector-based compression refrigeration system (ECRS) for electricity, cooling, and heating production. The ECRS is integrated with the topping PERC through an absorption refrigeration system (ARS). Moreover, the collector is indirectly connected to the system by a storage tank to increase the operating hours of the system. The performance of the system is evaluated by thermodynamic and economic analysis. The three-objective optimization result is a testament to the fact that utilizing PTSC brings about the best performance of the system. The system exergy efficiency (ηex) in the case of PTSC is 8.1 % and 24.9 % higher than in the case of LFC and dish collector, respectively. The economic performance of the system in the case of PTSC is superior to that of the dish collector. Furthermore, the PTSC case results in a relatively similar economic performance to the LFC case. The system produces power, cooling, and heating at rates of 200.8 kW, 564.9 kW, and 795.7 kW in the optimum case of utilizing PTSC, respectively. Moreover, ηex, total cost rate (C˙tot), and specific cost of tri-generation (ctri) are obtained as 11.48 %, 204.7 $h−1, and 44.91 $GJ−1, correspondingly. The results indicate that ηex of the proposed layout in the case of PTSC is superior to a comparable tri-generation configuration introduced in the field by 2.78 % points.

Flexible operation of nuclear hybrid energy systems for load following and water desalination

Nuclear hybrid energy systems (NHES) have the potential to provide dependable and emission-free electricity to the grid while also increasing the flexibility and reliability of the electrical grid. Molten salt reactor (MSR) technology can provide consistent, carbon-free electricity while also increasing efficiency, security, and sustainability and reducing nuclear waste. This study investigates the integration of Molten Salt Reactors (MSR) and conventional Pressurized Water Reactors (PWR) with desalination technologies: Direct Contact Membrane Distillation (DCMD), Multi-Stage Flash Distillation (MSFD), and Reverse Osmosis (RO). Dynamic first-principles models were developed and tested using real grid data from the New York Independent System Operator. The results demonstrate that nuclear power is capable of flexibly responding to changing grid demand while simultaneously producing clean water, particularly during periods of low electricity demand. The MSR-RO system was found to be the most efficient in electricity generation and water production, and all hybrid systems reduced CO2 emissions by 356,000 to 682,000 tons annually. Economic analysis reveals that nuclear desalination technologies are cost-competitive with conventional systems, especially when paired with RO. These findings confirm the technical feasibility and environmental benefits of nuclear hybrid systems for sustainable electricity and water production.

Strategic integration of residential electricity: An optimisation model for solar energy utilisation and carbon reduction

The Solar Combined Cooling, Heating, and Power (S-CCHP) system, distinct from traditional centralised generation, provides clean energy solutions by installing user-side renewable energy capture facilities like solar panels to address the energy crisis and mitigate global warming. Previous research on the design of S-CCHP for buildings has often emphasised self-sufficiency, with less focus on the role of these systems as energy suppliers on the market. However, it is feasible to install scaled-up solar facilities that generate enough power to export to the grid, reducing grid pressure and enhancing the renewable energy mix. This study analyses the optimal design deployment for electricity within the S-CCHP system, based on the Renewable Energy System for Residential Building Heating and Electricity Production (RESHeat) system installed in Limanowa. It aims to optimise owner energy deployment by strategically integrating electricity generation, hybrid storage, and the electricity market to maximise owner benefits. A Life Cycle Assessment is also conducted to explore greenhouse gas emissions across scenarios with different storage facilities and reuse rates. Results show that the optimal deployment of 264 PV panels, each with a rated power of 440 W, generates 105 MWh annually, resulting in the surplus of 90.18 MWh with a selling price of 115 EUR/MWh. Vanadium redox flow batteries offer the highest revenue (4922.01 EUR) with the lowest storage costs, while lithium-ion batteries have the lowest carbon emissions (1.22 t CO2 eq/y). Sensitivity analysis and revenue break-even analysis are further conducted to assess the robustness and financial viability.

Exploring the Potential of Solar Energy for Electricity and Heat Production in Azerbaijan

Taking use of Azerbaijan's advantageous geographic and climatic characteristics, this thesis investigates the potential of solar energy for the generation of heat and electricity in the nation. In order to assess the viability of solar photovoltaic (PV) systems for electricity production and solar thermal technologies for heating, it evaluates important places with significant sun insolation. The report points up difficulties including geographical variations in solar radiation and infrastructural constraints, but it also implies that these obstacles may be addressed by technical innovation and strategic planning. Azerbaijan's energy security and sustainability may be enhanced by implementing hybrid systems, supporting policies, and infrastructural enhancements that optimize the use of solar energy.

Study of the Management of the Electrical Energy Production and Distribution System Within the National School of Teachers of Mamou, Guinea

With the energy transition, marked essentially by the mass integration of energy production based on renewable resources, the missions and challenges of electrical energy distribution networks are evolving. This study is part of this dynamic, its objective is the study of the management of the production and distribution system of electrical energy within the National School of Teachers of Mamou. It emerges from this study that the supply of electrical energy to the National School of Teachers of Mamou is ensured by a hybrid system of three power sources: photovoltaic solar fields, Generator Group and Electricity of Guinea. The current electrical energy requirements of the Mamou NST are 40 kW. The total power of the installed photovoltaic solar fields is 70 kWp; the Generator used has a power of 10 kVA; the site’s Electricity of Guinea network is made up of transformers, cabin substations and protective equipment. The electricity distribution network is characterized by: Four (4) 250 A circuit breakers; a 32 A circuit breaker for the departure of lamps, sockets and fans; a 10 A circuit breaker for the lamps; a 10 A circuit breaker for the fans; a 16 A circuit breaker for the sockets and an 800 A mechanical inverter. The study shows that the power of photovoltaic solar fields is largely sufficient to cover the current electrical energy needs of the National School of Teachers of Mamou.

Water usage in cooling systems for electricity production: an event study of retrofitted coal-fired power plants in the United States

Water usage in cooling systems for electricity production: an event study of retrofitted coal-fired power plants in the United States

Toward sustainable energy resource: Integrated concentrated photovoltaic and membrane distillation systems for fresh water and electricity production

This study introduces and evaluates a novel Concentrated Photovoltaic (CPV)-assisted Direct Contact Membrane Distillation (DCMD) system, examining its efficiency and energy output under varying operational conditions. A Computational Fluid Dynamics (CFD) model, validated with experimental data, assesses the system's performance at different concentration ratios ranging from 1x to 10x and 25x to 100x, flow patterns (counterflow and parallel flow) at different Reynolds numbers (30–1200). This study investigates the seasonal performance of the CPV-DCMD system, providing valuable insights into its reliability and sustainability throughout the year. Results show increased mass flux and electric power with higher concentration ratios, especially at lower Reynolds numbers. In the counter-flow arrangement, the mass flux increases notably under specific conditions, while seasonal analysis reveals peak flux during summer and autumn afternoons. Electric power output follows a consistent trend across seasons, with high output observed during noon hours. The study demonstrates the system's energy efficiency, with notable energy gain compared to consumption across diverse operational conditions. Overall, the findings provide insights into optimizing the performance of CPV-assisted DCMD systems for sustainable energy generation and water desalination applications.

Analysis of the PV/T system for electricity and hot water production

Analysis of the PV/T system for electricity and hot water production

ELECTRICITY GENERATION METHODS FROM SOLAR ENERGY

In this study, photovoltaic cells that directly convert solar energy into electrical energy and concentrated solar energy technologies that indirectly generate electrical energy from superheated steam by concentrat-ing solar energy were examined in detail, classified among themselves, and compared technically. Exami-nations on electricity production methods and technologies from solar energy were carried out in three stages. In the first stage, a comprehensive scheme was created by examining the methods of electricity production from solar energy in general. In the second stage, the structures and types of photovoltaic cells were examined. In the third stage, concentrated solar energy systems were examined. Finally, electricity production systems from solar energy are compared and the results are presented.

A solar assisted grid-tied polygeneration system for hydrogen and electricity production: Future of energy transition from electrons to molecules

Climate change and energy crises are twin challenges that require collective wisdom and polygeneration energy systems for sustainable development. Hydrogen is an abundant element in the universe that can shape the future of energy transmission and storage from electrons to molecules. This paper presents utilization of a solar PV assisted hydrogen and electricity production and storage system for a university transportation fleet of 43 student transit buses to reduce annual 9842 liter fuel consumption and 26.52 Mt CO2 emissions. The system is designed, modeled, and simulated using TRNSYS® energy simulation software and optimized in TrnOpt linked to GenOpt for dynamic weather conditions of Gujrat (Pakistan), Fargo (USA), London (UK). As a model, the results of a 27kWp PV system are presented that assists an alkaline electrolyzer generating 12696 m3 hydrogen, 6348 m3 oxygen, 16848 KWh electricity exported to national grid and 11.56 GJ thermal energy annually. The proposed system generates energy vectors including hydrogen, electricity, heat, and oxygen with optimal performance during intermittent weathers. In this paper, a business model canvas is developed for solar PV assisted hydrogen production and storage system. These outputs can be accredited to the hydrogen as an energy alternative for green and sustainable future for transportation sector.

Techno-economic analysis of a grid/fuel cell/PV/electrolyzer system for hydrogen and electricity production in the countries of African and Malagasy council for higher education (CAMES)

The current electricity challenges in Africa have spurred the interest of governments in incorporating renewable energy sources into the energy mix. The use of hybrid solar energy systems has become a practical choice for electrification. The novelty of the paper is threefold: (i) The Grid/Fuel Cell/PV/Electrolyzer hybrid system is modeled, simulated, and optimized in for some communities of the nineteen countries of the African and Malagasy Council for Higher Education (CAMES) for the very first time; (ii) The levelized costs of hydrogen and energy were evaluated and compared; (iii) PV, fuel cell, grid purchases, and grid sales power productions were determined and compared. The study findings showed a levelized cost of energy varying between US$ 0.238/kWh (in Madagascar) and US$ 0.344/kWh (in Gabon). Subsequently, among the West, Central, and East African countries of CAMES, Mali, Chad, and Burundi were the countries with the smallest LCOE respectively. Also, the levelized cost of hydrogen ranged between US$ 1.84/kg (in Madagascar) and US$ 2.17/kg (in Gabon and Equatorial Guinea). The computation of the net present cost indicated a variation between 183,536 US$ (in Madagascar) and 216,115 US$ (in Gabon). The PV, fuel cell, grid purchases, and grid sales power productions were between 34,044 kWh/year (in Gabon) and 53,176 kWh/year (in Mali) for PV productions; between 43,526 kWh/year (in the Democratic Republic of Congo) and 43,784 kWh/year (in Chad) for fuel cell productions; between 29,976 kWh/year (in Senegal) and 30,700 kWh/year (in the Congo Republic) for grid purchases power productions; and between 11,604 kWh/year (in Gabon) and 29,608 kWh/year (in Mali) for grid sales productions respectively. It was concluded that the PV power production was the highest power generated by the hybrid system when compared with fuel cell, grid sales, and grid purchases power productions. Concerning the PV penetration, it varied between 54.2 % (in Gabon) and 84.7 % (in Mali). The present work is aimed at decision-makers so that they become aware of the need to urgently develop the renewable energy sector in the countries for a successful energy transition in Africa.

Experimental study on a solar-powered cogeneration system for freshwater and electricity production.

In this study, a photovoltaic/thermal (PVT) collector and a stepped solar still system were constructed and integrated. The PVT collector was used to improve the performance of a stepped solar still device. Saltwater enters into the PV-T system and the temperature of the solar panel declines, and then ultimately the efficiency of the PV-T collector increases. After leaving the PVT collector, the temperature of the saltwater increased and was used as a pre-heater for further evaporation in the solar still, which ultimately caused an increase in its efficiency. The more tremendous temperature difference generated between the stepped surface and the glass increases efficiency and produces more freshwater. A flow rate of 7.5 L/hour of saline water was used to study the efficiency of the solar still device and the PVT collector. The value of productivity of solar still system with photovoltaic/thermal collector was 0.76kg/m2 more than that of conventional solar still. Despite the PVT collector, the daily efficiency of the solar still system increased to 34.8%, which shows an increase of 13.9% compared to the passive solar still device. Also, by cooling the PV-T system, the average electrical efficiency has increased from 13.1 to 13.7%. Production power reached 72.46 W from 65.96 W in two consecutive days at 11:15.

Dynamic performance analysis of a photovoltaic thermal (PVT) collector with an extruded absorber using python optimization modeling object (Pyomo)

Solar photovoltaic thermal (PVT) integrates photovoltaic panels and solar thermal collectors in one system for simultaneous electricity and heat production in a reduced area. The absorber type used for heat extraction significantly affects PVT performance. This work examines the performance of an extruded absorber PVT under varying solar irradiance, ambient temperature, and wind speed. A detailed dynamic mathematical model is developed from energy balance equations and heat transfer correlations for each layer of the PVT collector. Using orthogonal collocation on the finite difference method, the system of differential equations is discretized and solved numerically with Pyomo, a Python optimization modeling tool. Following validation against literature data, the model is used to predict the temperature of each layer and the thermal and electrical output of the PVT collector. The effect of cooling fluid mass flow rate, solar irradiance intensity, ambient temperature, and wind speed on PVT performance is analyzed. This design provides a maximum electrical efficiency of 15.47 % at a wind velocity of 3 m/s, regardless of the cooling fluid flow rate. Peak electrical power of 212.26 W is achieved at the highest flow rate (14.14 kg/hr) and with the highest wind velocity (3 m/s), while the peak thermal power of 348.03 W occurs at a wind velocity of 1 m/s and a flow rate of 11.31 kg/hr. Compared to the conventional sheet-and-tube design at 1 m/s wind speed and 5.65 kg/hr cooling fluid flow rate, the extruded absorber PVT delivers 203.18 W electrical and 189.27 W thermal power, outperforming the 207.46 W electrical and 128.9 W thermal power of the conventional design, demonstrating the potential of the extruded absorber design for enhancing heat generation.

Alternative Approach for Thermo-Hydraulic Modeling of Direct Steam Generation in Parabolic Trough Solar Collectors

Abstract The implementation of direct steam generation in linear concentrators is limited mainly by the complexity and the high demand for computational resources of the models developed to predict the installation behavior. With this in mind, we introduce an innovative methodology to characterize the thermo-hydraulic behavior of direct steam generation in parabolic trough solar collectors, with a strong focus on two-phase flow phenomena. Our proposed approach has resulted in a generalized function that eliminates the need for the convective coefficient h and enables accurate prediction of the flow pattern within the receiver. By comparing our model with experimental data from the literature, we achieved relative squared errors (RSEs) values of less than 3% for temperature and pressure calculations, thus validating the robustness of our methodology. The Taitel and Dukler diagram confirms an appropriate flow pattern, while intermittent flow is observed initially during boiling; the pressure drop, although slightly elevated compared to direct solar steam (DISS) loop results, remains within acceptable limits; and the model demonstrates suitability for assessing liquid water, phase change, and superheated steam temperature evolution along the loop. Moreover, we further showcased the practical application of our developed model by applying it to a specific case study conducted in Agua Prieta, Sonora (Northwest México). The validated model exhibits versatility and is applicable to various cases, including both concentrating systems for electricity production and solar heat for industrial processes.

Energetic Valorization of the Innovative Building Envelope: An Overview of Electric Production System Optimization

The world population increased from 1 billion in 1800 to around 8 billion today. The Population Division of the United Nations predicts a global population of approximately 10.4 billion people by the end of the century. That represents over 2 billion more people. Moreover, the global community is currently experiencing a precarious state due to the enduring repercussions of the COVID-19 pandemic across all sectors, including energy. Given the rising global population and the limited availability of primary energy resources, we must reach a balance between the demands of a growing human population and the planet’s carrying capacity. The dreadful conflict in Ukraine has precipitated an enormous energy crisis. This crisis has served as a warning to the world population of how much it depends on this resource to survive. In France, the building sectors, specifically residential and tertiary, account for 45% of the total final energy consumption. It is the first energy consumer of the country and one of the most polluting (i.e., about 34% of CO2 emitted by France). Consequently, we must consider alternative energy resource forms (i.e., substitution energy forms). Harvesting energy from the building envelope may be a viable technique for partially satisfying the electricity demands of building users. In this context, scientific research offers considerable potential for developing more innovative and efficient systems. This article aims to review the state-of-the-art of advances on the subject to orient and further optimize energy production systems, particularly electricity. This work addresses several points of view: it discusses the overall backdrop of the present study and introduces the subject; details the research strategy and procedures used to produce this paper; develops the state-of-the-art on the potential for generating or recovering power from the building envelope; presents the SWOT analysis of the earlier-described systems. Finally, it concludes by offering findings and viewpoints.

Zero energy building optimization for a residential complex with a new optimized cogeneration system for electricity, cooling, heating and freshwater production

In this research, a multi-generation system was proposed to meet the energy consumption of a 120-unit zero-energy residential complex with 100 m2 and 2 bedrooms in Sydney, Australia. To meet the heating and cooling demand of the residential complex, a compression chiller was used, and electrical energy was provided using the system's production power. The main goal of this research is to define a zero-energy building by providing the energy consumption of a residential complex with a solar system. Building Energy Optimization (BEopt) Software has been used for the process of simulating the residential complex and extracting the required load of the residential complex. The design of the load supply system of the residential complex was done using EES thermodynamic software. In this research, a large number of inputs have been used in different scenarios to optimize the residential complex, and the tool used in this research by all the modes introduced as inputs turns the problem into a multi-objective optimization problem. The results of the investigation of the residential complex showed that the amount of electricity consumption, heating, and cooling of the residential complex during the year is 36728, 133123, and 17,902 kWh, respectively. Also, by optimizing the energy consumption of the residential complex, it is possible to reduce CO2 emissions and prevent the increase in environmental pollution. The optimal results showed that the system in its most optimal state can reach an exergy efficiency of 25.18 % and a system cost rate of 46.6 $/h. The performance of the system in the city of Sydney showed that the system can produce 166,164 kWh of electricity, 467,945 kWh of heating, and 183,370 kWh of cooling in one year. Comparing the results of residential complex consumption load and system production showed that the proposed system can easily provide the residential complex consumption load throughout the year.

Alternatives for the Optimization and Reduction in the Carbon Footprint in Island Electricity Systems (IESs)

The penetration of renewable energies in island electricity systems (IESs) poses a series of challenges, which include, among others, grid stability, the response to demand, and the security of the supply. Based on the current characteristics of electricity demand on the islands of the Canary Archipelago (Spain) and their electricity production systems, this study presents a series of alternative scenarios to reduce greenhouse gas (GHG) emissions and increase the penetration of renewable energies. The goal is to optimize combustion-based (nonrenewable) energy production and combine it with renewable-based production that meets the requirements of dynamic response, safety, scaling, and integration with nonrenewable systems in terms of efficiency and power. As verified in the research background, the combination of power producing equipment that is generally employed on the islands is not the best combination to reduce pollution. The aim of this work is to find other possible combinations with better results. A methodology is developed and followed to obtain the lowest GHG production and to determine the measures to be applied based on: (a) changing the fuel type by switching to natural gas in the equipment that allows it; (b) using optimal combinations of the least polluting energy production equipment; (c) integrating, to the extent that it is possible, the Chira-Soria pumped hydroelectric energy storage plant into the Gran Canaria electricity system. A series of alternative scenarios are generated with different operating conditions which show the possibility of increasing the renewable installed capacity in the Canary Islands by up to 36.78% (70% in Gran Canaria), with a 65.13% reduction in GHG emissions and a 71.45% reduction in fuel consumption. The results of this study contribute, through the different measures determined through our research, to the mitigation of GHG emissions.

GRU 기반의 농장 내 전력량 관리 및 이상탐지 자동화 시스템 설계

Power efficiency management in smart farms is important due to its link to climate change. As climate change negatively impacts agriculture, future agriculture is expected to utilize smart farms to minimize climate impacts, but smart farms' power consumption may exacerbate the climate crisis due to the current electricity production system. Therefore, it is essential to efficiently manage and optimize the power usage of smart farms. In this study, we propose a system that monitors the power usage of smart farm equipment in real time and predicts the power usage one hour later using GRU. CT sensors are installed to collect power usage data, which are analyzed to detect and prevent abnormal patterns, and combined with IoT technology to efficiently manage and monitor the overall power usage. This helps to optimize power usage, improve energy efficiency, and reduce carbon emissions. The system is expected to improve not only the energy management of smart farms, but also the overall efficiency of energy use.

Design and implementation of an efficient hybrid system for electricity production

The interfacial layer in a Schottky barrier solar cell plays an important role in determining the short circuit current, open circuit voltage, fill factor and efficiency of the cell. In this paper, we studied the effects of interfacial oxide layer thickness, interface state density and Ф0 (the level above the valence band to which surface states are filled in isolated semiconductor) on the open circuit voltage and efficiency of the SnO2/SiO2/Si (N) solar cells. From our analysis, we have found that the efficiency of the cell increases at first with the interfacial oxide layer thickness δ, and after acquiring a maximum value falls with a further increase of δ. We have optimized the interfacial layer thickness for maximum efficiency. The solar cell current–voltage characteristics under illumination are also computed for different values of insulator thickness δ. The results obtained by numerical simulation using Matlab programs are presented and discussed. The SnO2/SiO2/Si (N) solar cells, in which the interfacial oxide layer thickness is optimized to 21 A°, have an average open circuit voltage of 0.62 V and a short circuit current of 36 mA/cm². The calculated conversion efficiency of the cells can be as high as 17.5 %.