Electricity Production System Research Articles

Assessment of the performance of a low-temperature Organic Rankine Cycle engine coupled with a concentrating PV-Thermal system

The operation of an integrated CPVT/ORC unit is investigated to identify the possibility of combining efficiently an ORC engine with a CPVT collectors’ field. The combined system is designed to operate so that the heat provided by the CPV field is at a temperature level in the range of 70–90 °C. The performance of the ORC engine is assessed towards comprehending its behavior under varying thermal loads and, as a result, maximizing the overall system electricity production. The analysis reveals that the electricity production from the ORC engine may be in the order of approximately 17 % of the total output of the combined system and that the implementation of the examined technological solution could increase the solar energy conversion efficiency of the CPV field, provided that the ORC engine operates at its maximum thermal efficiency. Finally, the preliminary economic analysis highlighted the potential of the integrated unit, which could be competitive even for small-scale systems.

Feasibility study of a new solar based trigeneration system for fresh water, cooling, and electricity production

The utilization of solar energy to generate electricity, cooling, and freshwater in remote areas in a sustainable way still poses lots of challenges to researchers. The aim of the current study is to design a new solar-operated trigeneration system to produce electricity, cooling, and fresh water using parabolic trough collectors in remote areas. Electric power is generated by using Organic Rankine Cycle, and cooling and fresh water (using freezing desalination technique) are obtained by two-stage NH3–H2O vapor absorption system run by solar energy. Simulation results show that for PTC arrays of 200 m2, an electrical output obtained is 3.3 kW, cooling rate is 20.4 kW, and mass flow rate of freshwater produced is 36 kg/h for an average solar irradiation of 0.7 kW/m2. Furthermore, sensitivity analysis is conducted by varying the parameter like solar irradiation, evaporator temperature, seawater inlet temperature, etc. and their effect on performance characteristics of the overall setup is investigated.

Low emission vehicle integration: Will National Grid electricity generation mix meet UK net zero?

Assessing greenhouse gas (GHG) emissions produced from electric vehicles (EVs) and hydrogen vehicles (HVs) requires understanding of the carbon intensity of electricity generation. Without the decarbonisation of electricity generation, environmental benefits of low emission vehicles (LEVs) will be diminished. The UK aims to produce net zero emissions by phasing out and banning the sale of new conventionally fuelled vehicles (CFVs) by 2035 in favour of LEVs. A comparison of the UK’s planned and future electricity production systems between 2020 and 2050 was conducted to analyse different vehicle-type mix scenarios: (1) 100% CFVs, (2 A/B) 100% EVs/HVs, (3 A/B) EVs/HVs integrated from 2035 and (4 A/B) EVs/HVs integrated from 2025 onward. This was conducted using four energy scenarios from the UK National Grid: two degrees, steady progression, consumer evolution and community renewables. This study does not consider the embedded carbon costs of the construction and decommissioning of vehicles. Results demonstrated that while the four electricity generation scenarios reduce the projected emissions they fail to achieve low emission targets. The two degree scenario produced the lowest level of emissions under each vehicle-type mix scenario. Technological improvements of CFVs are not enough to meet targets. Therefore, phasing out and banning the sale of new CFVs from 2025 (rather than 2035) would provide a stronger impetus to reduce transport emissions. Although these targets are possible, encouraging a change in transport modes from individual travel to public transport whilst simultaneously replacing buses and trains with electric or hydrogen alternatives would see a greater emission decrease.

A Novel Electricity and Freshwater Production System: Performance Analysis from Reliability and Exergoeconomic Viewpoints with Multi-Objective Optimization

Based on the benefits of integrated gasification combined cycles (IGCCs), a cogeneration plant for providing electricity and freshwater is proposed. The main novelties of the devised system are the integration of biomass gasification and a regenerative gas turbine with intercooling and a syngas combustor, where the syngas produced in the gasifier is burned in the combustion chamber and fed to a gas turbine directly. The energy discharged from the gas turbine is utilized for further electricity and freshwater generation via Kalina and MED hybridization. The proposed system is analyzed from energy, exergy, exergoeconomic, and reliability–availability viewpoints. The optimal operating condition and optimum performance criteria are obtained by hybridizing an artificial neural network (ANN), the multi-objective particle swarm optimization (MOPSO) algorithm. According to results obtained, for the fourth scenario of the optimization process, optimal values of 45.10%, 14.27 kg·s−1, 12.95 USD·GJ−1, and 8141 kW are obtained for the exergy efficiency, freshwater production rate, sum unit cost of products, and net output power, respectively. According to reliability and availability assessment, the probability of the healthy working state of all components and subsystems is 88.4403%; the system is shown to be 87.74% available of the time over the 20-year lifetime.

Current State of the Worldwide Renewable Energy Generation: a Review

The purpose of this study is to undertake a global review of the renewable energy generation's current state, specifically in the area of photovoltaic (PV) solar energy, wind energy, bioenergy and hybrid power systems for electricity production. This article presents the most relevant aspects of the progress and the experiences of countries aiming at the construction and implementation of these technologies. It also quotes studies that include the advances of countries seeking to contribute to the decrease of greenhouse gas emission or that due to their geographic and environmental conditions are attempting to improve the access and the quality of the electric energy generation, involving especially remote communities that could hardly connect to the national power grid because of techno-economic reasons. These renewable energy studies could lead off to evaluate the impact of clean energy in the global energy supply and demand. Although in general, these technologies require high investments hardly competitive with traditional energy, with the support of stable policies and government subsidies, these become a choice that grows exponentially every day concerning efficiency and the reduction of costs, which can build trust in new investors.

Dataset for the Solar Incident Radiation and Electricity Production BIPV/BAPV System on the Northern/Southern Façade in Dense Urban Areas

The prosperous implementation of Building Integrated Photovoltaics (BIPV), as well as Building Attached Photovoltaics (BAPV), needs an accurate and detailed assessment of the potential of solar irradiation and electricity production of various commercialised technologies in different orientations on the outer skins of the building. This article presents a dataset for the solar incident radiation and electricity production of PV systems in the north and south orientations in a dense urban area (in the northern hemisphere). The solar incident radiation and the electricity production of two back-to-back PV panels with a ten-centimetre gap for one year are monitored and logged as primary data sources. Using Microsoft Excel, both panels’ efficiency is also presented as a secondary source of data. The implemented PV panels are composed of polycrystalline silicon cells with an efficiency of 16.9%. The results depicted that the actual efficiency of the south-facing panel (13–15%) is always closer to the standard efficiency of the panel compared to the actual efficiency of the north-facing panel (8–12%). Moreover, although the efficiency of the south-facing panel on sunny days of the year is almost constant, the efficiency of the north-facing panel decreases significantly in winter. This phenomenon might be linked to the spectral response of the polycrystalline silicon cells and different incident solar radiation spectrum on the panels. While the monitored data cover the radiation and system electricity production in various air conditions, the analysis is mainly conducted for sunny days, and more investigation is needed to analyse the system performance in other weather conditions (like cloudy and overcast skies). The presented database could be used to analyse the performance of polycrystalline silicon PV panels and their operational efficiency in a dense urban area and for different orientations.

Exergoeconomic assessment and multiobjective optimization of a geothermal-based trigeneration system for electricity, cooling, and clean hydrogen production

Exergoeconomic assessment and multiobjective optimization of a geothermal-based trigeneration system for electricity, cooling, and clean hydrogen production

Implementation and Simulation of Real Load Shifting Scenarios Based on a Flexibility Price Market Strategy—The Italian Residential Sector as a Case Study

This work aims to evaluate the Flexibility Potential that a residential household can effectively provide to the public grid for participating in a Demand Response activity. In detail, by using 14 dwellings electrical data collection, an algorithm to simulate the Load Shifting activity over the daytime is implemented. That algorithm is applied to different scenarios having considered the addition of several technical constraints on the end users’ devices. In such a way, more realistic demand-side management actions are implemented in order to assess the Flexibility Potential deriving from the loads shifting. Basically, by performing simulations it is possible to investigate how the household appliances real operating conditions can reduce the theoretical Flexibility Potential extent. Starting from a Flexibility Price-Market-based Strategy, this work simulates the shifting over the day and night-time of some flexible loads, i.e., the shiftable and the storable ones. Specifically, all instants where load curtailments and enhancements occur over the typical day, the flexibility strategy effectiveness in terms of percentage, the power and energy that are potentially flexible, are evaluated. All the simulations are performed only for residential consumers to evaluate the actual dwellings Flexibility Potential in the absence of any electrical storage and production systems. The outcomes of these simulations show an average Theoretical Flexibility reduction, which is calculated as the fraction of appliances’ cycles shifting over the total ones, equal to 53%, instead of 66%; in a single dwelling, a maximum variation equal to 29% has been registered. In the end, the monthly average shifted energy per dwellings decreases from 27 to 18 kWh, entailing 32.5% off.

Sustainable Strategies for the Exploitation of End-of-Life Permanent Magnets

The growing production of green technologies (such as electric vehicles and systems for renewable electricity production, e.g., wind turbine) is increasing the rare earth element (REE) demands. These metals are considered critical for Europe for their economic relevance and the supply risk. The end-of-life permanent magnets are considered a potential secondary resource of REEs thanks to their content of neodymium (Nd), praseodymium (Pr) or dysprosium (Dy). The scientific literature reports many techniques for permanent magnet recovery. This work used a life cycle assessment (LCA) to identify the most sustainable choice, suggesting the possible improvements to reduce the environmental load. Three different processes are considered: two hydrometallurgical treatments (the first one with HCl and the other one with solid-state chlorination), and a pyrometallurgical technique. The present paper aims to push the stakeholders towards the implementation of sustainable processes for end-of-life permanent magnet exploitation at industrial scale.

Cogeneration system driven by solar dish concentrators

AbstractThe objective of this study is the investigation of a cogeneration system for heating and electricity production, which is driven by solar dish concentrators. There is an organic Rankine cycle (ORC) driven by the solar field and produces electricity with its turbine and heating from its condenser. The solar field includes 100 m2 of solar dish concentrators with spiral absorber and an insulated storage tank of 4 m3 storage volume. The system is examined parametrically for different pressure levels in the turbine inlet and superheating degree. The system exergy efficiency is maximized for a superheating of 30 K and a maximum pressure equal to 70% of the toluene critical pressure. In this case, the system produces 12.41 kW electricity, 28.55 kW heating, while the energy efficiency is 51.20%, and the exergy efficiency is 20.69%. Moreover, the system is examined for a typical sunny day, and it is found that the electricity production is 125.6 kWh, the heating production 288.86 kWh, the energy efficiency 48.96%, and the exergy efficiency 19.77%. In the end, the simple payback period of the examined system is found at 6.28 years, which is a good value.

An integrated bifacial photovoltaic and supercritical geothermal driven copper-chlorine thermochemical cycle for multigeneration

This study thermodynamically investigates a newly developed supercritical geothermal and solar-based integrated energy system and applies to a local community which is near Kakkonda, WD-1a geothermal plant in Shinozaki, Japan. The proposed system produces useful outputs, such as electricity, heat for space heating and freshwater for self-consumption in the community and the auxiliary systems and hydrogen for commercial purposes. Thermochemical copper-chlorine cycle, bifacial photovoltaic plant, Rankine cycle, heat pump, and multi-effect water desalination subsystems are integrated into this unique system to employ solar, geothermal, and sea sources to produce useful outputs. The overall system and its components are analyzed thermodynamically using both energetic and exergetic approaches. The parametric studies and dynamic time-dependent simulations are carried out for performance assessment. The economic comparison methods are applied to determine feasibilities. According to the calculations, 2,144.45 tons of hydrogen is produced annually. A total of 204 households is considered to consume 1235 MWh electricity, 851 MWh thermal energy and 5,314.75 tons of freshwater annually. The overall energy and exergy efficiencies are 22.7% and 18.2%, respectively, for the average ambient conditions. The unit costs of useful commodities are found to be 2.73$/kg for the hydrogen, 0.023$/kWh for the electricity, 0.015$/kWh for the thermal energy, 0.47$/m3 for the freshwater. The overall system shows 5.15 years payback period with a 22% internal rate of return. The proposed subsystems and overall system possess environmentally benign, sustainable and reliable electricity, space heating, fresh water and hydrogen production system.

CFD model for tubular SOFC directly fed by biomass

The coupling between biomass gasification and Solid Oxide Fuel Cells can represent a sustainable and efficient system for electricity production. This work aims to develop a preliminary model for the operation of a tubular, electrolyte-supported fuel cell (SOFC) fed by a syngas mixture. The fuel required by the SOFC system is produced inside the energy generator box from an integrated biomass gasification system. This study stems from the European DB-SOFC project, that proposed the exploitation of the abundant biomasses deriving from agricultural residues for energetic purposes (as from olive oil and wine production). In this study, the main processes have been simulated to find a possible configuration to obtain a power value of 200 W. 25 cells were used in the model to produce the required power. The results showed that at 0.7 V it is possible to achieve 12.3 W, when the biomass gasification was integrated into the SOFC box, while it was possible to achieve 9.6 W when the system was fed by externally produced syngas.

Simulation of a moving bed chemical looping system for electricity production from coal via chemical looping water splitting

AbstractCoal is a crucial energy source for modern industry and society. Because coal is one of the most CO2‐intensive carbonaceous fuels, the combustion of coal with CO2 capture is of great environmental relevance. However, the conventional coal‐based power generation processes, including the pulverized coal (PC) boiler process and the integrated gasification combined cycle (IGCC) process, suffer a significant efficiency loss when integrated with conventional CO2 capture methods. Chemical looping technology is a promising alternative pathway for coal‐based power generation with intrinsic CO2 separation and capture. Process simulation of chemical looping processes can provide an overview on the viability of the processes, thereby quantifying their advantages over conventional processes. This study presents the process simulation of a chemical looping water splitting combined cycle (CLWS‐CC) system for electricity generation. The CLWS‐CC process directly uses coal as the feedstock to produce H2, which is subsequently combusted in a combined cycle to generate electricity. The oxygen carriers used in the chemical looping process are optimized in their composition. Autothermal operation is established within the chemical looping system. Four CLWS‐CC cases that operate at different pressures are considered. In two of the four cases, an unequal pressure operating strategy is adopted to minimize the compression power consumption in order to enhance the overall process energy efficiency. The process simulation shows that the CLWS‐CC process is able to achieve an 18% increase in net plant efficiency over the conventional IGCC process.

Experimental and Theoretical Investigation of Performance of a Solar Chimney Model, Part I: Experimental Investigation

This paper presents the experimental data that was collected from small pilot solar chimney. The experimental data together with ambient conditions are used to evaluate the performance and study the behavior of the solar chimney; this data will be used for comparison with theoretical models in another paper [part II). The solar chimney prototype was designed and constructed at the Subrata Faculty of Engineering-Libya. The data were collected over several days of June 2011. The solar chimney system contains two main components; the solar collector and the solar chimney. The solar collector root‘ has a circular area of126 m3, the solar chimney is a PVC tube with internal diameter of 0.2 m and the total height of chimney is 9.3 m. The measurements include the intensity of solar radiation inside/outside the collector, temperature and velocity of air at the entrance of the chimney, temperature and speed of wind outside the collector, temperature of the ground inside collector al1d temperature measurements of air at speci?c points at different levels throughout the collector. Solar irradiance was found to affect the chimney temperature and subsequently affects chimney air velocity. The experimental results showed that temperature differences of (30 - 45°C) were recorded between the ambient temperature and that of air inside the chimney in the middle of the day, where the highest air temperature of 73.4°C was recorded at the entrance of the solar chimney. The maximum air velocity of 3.6 m/s was recorded inside the solar chimney at noon on 9 June. Wind speed outside the collector had a small effect on the speed of the air inside the chimney and tends to change slightly, hence, can neglect influence of wind speed on the performance of the system. Also the experimental results indicate that such type of system can trap a suf?cient amount of solar radiation, which elevates the air temperature to a suf?cient value able to generate enough air ?ow to operate a wind turbine to produce electricity; this means the solar chimney system for electricity production can work in the north-western part of Libya in the summer time at least.

Simple mathematical model to predict the amount of energy produced in wind turbine - preliminary study

The manuscript presents a simple mathematical model for predicting the amount of energy produced in a wind turbine. As part of the own research, the data obtained from the SCADA program for the Enercon E-82 wind turbine was analyzed. It has been shown that it is possible to build a mathematical model to determine the amount of energy produced from the average wind speed. This method will be primarily useful for forecasting the volume of production as well as electricity demand, with particular emphasis on renewable energy sources. The application of the developed method in practice will facilitate and accelerate the implementation of the decision-making process in electricity production systems, while reducing the risk of error. This model can also be used to make repowering decisions.

ВСТАНОВЛЕННЯ ДАХОВОЇ СОНЯЧНОЇ (ФОТОВОЛЬТАЇЧНОЇ) ЕЛЕКТРОСТАНЦІЇ ДЛЯ КОТЕДЖНОГО КОМПЛЕКСУ ЖИТЛОВИХ БУДИНКІВ ПОТУЖНІСТЮ 401,21 кВт•пік

The publication is devoted to alternative energy in the general system of electricity production, in particular, solar power plants. Prospects for the introduction of solar energy in households in Ukraine are studied. An assessment of the potential use of solar energy in Ukraine is given. The risks of investing in solar power plants are analyzed.

PSO Control under Partial Shading Conditions

The change observed in new habits and traditions of human beings has significantly influenced the way of their current life especially in their needs for electrical energy.This has consequently increased the demand for energy, which has forced the researchers and the industrials to focus their efforts in the development of electricity production systems based on renewable energies, such as photovoltaic (PV), thermal, hydraulic, etc. In the case of the photovoltaic installations, the random change in climatic conditions is considered as a challenge for the engineers in the field. Moreover, the phenomenon of partial shading prompts scientists to suggest practical solutions to overcome it while ensuring the desired performance of the installation. The Maximum Power Point Tracking technique is considered to improve the dynamic performance of the photovoltaic system. Our contribution deals the research of a point of maximum power for a photovoltaic system, under conditions of partial shade using particle swarm optimization algorithm (PSO). The simulation of this structure under the Matlab/ Simulink environment shows that the system ensures better performance and good efficiency.

The Effect of a Dynamic Lens Structure on the Open Circuit Voltage of a Concentrated Photovoltaic Model

The current concerns of energy shortage and global warming have brought the development of strategies to utilize renewable energy resources at the forefront of public interest. Solar power is one of renewable energy's most promising sources. Concentrated photovoltaics can significantly improve a photovoltaic (PV) system's electricity production. This paper presents a novel approach of a CPV unit with a dynamic lens structure. Design and Implementation of both electrical and mechanical design in order to move the lens to achieve a better voltage output. Experiments had been carried out and measurements were taken according to the light source which was the sun in one case and the artificial light in the other. Based on the experimental results the effect of the dynamic lens was studied and compared to the fixed lens. The results showed that the dynamic lens CPV model was more effective and efficient than the fixed one.

Comparision of Ancillary Services and Renewable Energy Sources’ Impact on Balancing of the Power System in ENTSO-E

Abstract This paper specifies and compares the ancillary services used by transmission system operators in selected countries within ENTSO-E (European Network of Transmission System Operators-Electricity) for operational needs of their transmission systems. The comparison of the ancillary services’ unit prices is also given. In addition, analyses of various experiences gained by ENTSO-E countries within their electric power systems in relation to initiatives supporting the power generation from renewable energy sources (RES) and the methods of their integration into the electric power system were made. Namely, depending on the total amount of RES, depending on the incentive system for electricity production from RES and the development of an organized electricity market, different balancing responsibility models for electricity producers from RES were established.

Design and economic analysis of off-grid solar PV system in Jos-Nigeria

Around the globe, renewable energy sources and their associated technologies are critical to power generation. The solar photovoltaic (PV) system is one of the renewable energy systems supporting electricity consumption in the residential domain. Despite the potential of solar PV as well as an appreciable amount of global solar radiation in the region, no previous study has examined the viability of the PV system for off-grid electricity production in Jos, Nigeria. This paper focuses on examining the feasibility of deploying an off-grid PV system to drive the electricity consumption of a residential building in Jos, Nigeria (9.9ON, 8.9OE, 1204.87 m). The paper adopts a mathematical modelling method for designing and analyzing the entire PV systems to drive the power consumption of the households. By applying mathematical modelling approach, the results demonstrate that 10 MLE275HD2 PV modules each of 275 Wp and five batteries of 100 Ah can satisfy the annual electricity consumption of approximately 3132 kWh. Further, an economic analysis carried out by using the life-cycle cost (LCC) analysis depicts that the LCC, the annualized life-cycle cost (ALCC) and cost of electricity (COE) to be US$ 10,110.85, US$ 593.75 and US$ 0.18/kWh respectively. The results of this modelling demonstrate both the technical and economic viability of the off-grid PV system for power generation, and can serve as a model to the successful development of the system for real application. Further, the model can encourage the stakeholders in the renewable sector to provide the support mechanisms towards the adoption of the PV system in the residential buildings.