Additional Electrical Energy Research Articles

High-Porosity Lamellar Films Prepared by a Multistage Assembly Strategy for Efficient Photothermal Water Evaporation and Power Generation.

The frame structure combined with water- and heat-transfer capabilities fully satisfies the requirements of photothermal conversion materials in seawater evaporation applications. Meanwhile, it must integrate the characteristics of a high photothermal conversion rate, thermal management, and water transportation. Herein, lamellar porous films were successfully designed and synthesized by a simple ultrasonic-assisted vacuum filtration method. In this process, polystyrene sulfonate@carbon nanotubes/reduced graphene oxide (PSS@CNT/rGO) lamellar films were constructed by the one-dimensional synthesis of PSS@CNT self-assembled at the molecular scale and the two-dimensional matrix material rGO. It is worth noting that the lamellar film exhibits a high specific surface area (285.5 m2·g-1), which is reflected in its abundant nanopores. Among them, the porous network system composed of nanochannels can provide efficient water supply and steam-transfer ability and strengthen the heat insulation performance of thermal localization, which is beneficial to photothermal evaporation. The obtained PSS@CNT/rGO lamellar films achieved a condensed water yield of 1.825 kg·m-2·h-1 under 1 sun illumination (1 kW·m-2), and their solar-vapor conversion efficiency was 97.1%. Simultaneously, the interaction between the water flow and the carbon material interface was also used to generate additional electric energy output. The maximum open-circuit voltage of 0.46 V was generated at both termini of the PSS@CNT/rGO lamellar film, which successfully realized the multieffect utilization of energy. These results show that the multistage assembly strategy is a facile and effective means for the development of an efficient evaporation photothermal film, which offers significant value in the field of photothermal seawater evaporation and power generation.

Techno-economic evaluation of a grid-connected PV-trigeneration-hydrogen production hybrid system on a university campus

Many universities have plans to reduce campus energy consumption with developed energy efficiency strategies, supply the energy needs of the university campus with renewable energy and create a green campus. In order to serve this purpose, this study focuses on the simulation of the installation of an on-grid photovoltaic (PV) power system at the Vocational Colleges Campus, Hitit University. On the other hand, the integration of the simulated PV system with a gas fired-trigeneration system is discussed. Moreover, the study explores opportunities for solar hydrogen generation without energy storage on campus. For the PV system simulation, three different scenarios were created by using web-based PV system design software (HelioScope). Installed powers in the simulation were found as 94.2 kWe, 123.9 kWe, and 157.5 kWe for the low scenario (on the rooftop), high scenario (on the rooftop), and the high + PV canopy arrays scenario (on the rooftop and an outdoor parking area), respectively. The levelized cost of electricity (LCOE) values were 0.061 $/kWh, 0.065 $/kWh, and 0.063 $/kWh for the low scenario, high scenario, and the scenario including PV canopy, respectively. The energy payback time is found to be 6.47–6.94 years for the 20–25 years lifetime of the PV plant. The simulation results showed that the PV system could support it by generating additional electrical energy up to 25% of the existing system. The campus can reduce GHG emissions of 1546–2272 tonnes-CO2eq, which is equivalent to 142–209 ha of forest-absorbing carbon unused during the life of the PV system. Depending on the production and consumption methods utilized on campus, which is a location with relatively large solar potential, the levelized cost of hydrogen (LCOH) of hydrogen generation ranged from 0.054 $/kWhH2 (1.78 $/kgH2) to 0.103 $/kWhH2 (3.4 $/kgH2). Consequently, with proper planning and design, a grid-connected PV-trigeneration-hydrogen generation hybrid system on a university campus may operate successfully.

Methodological Bases of the Fire Hazard Reduction in Internal and External 0.38 kV Electrical Networks with Unbalancing Power Consumption

The article shows that the operation modes in three-phase four-wire 0.38 kV electrical networks are objectively associated with unbalancing power consumption. As a result, significant additional electrical energy thermal losses occur in the neutral conductor’s internal electrical networks and external electrical networks l elements, which not only increase the electrical energy consumption, but also create conditions for the fire-hazardous occurrence single-phase short circuits. A mathematical model is proposed, an algorithm and a program for calculating the limit zero sequence values flows in external neutral conductors and internal 0.38 kV electrical networks are developed. Numerical calculations are made and tabular these limit values data for different conductors’ sections made of various conductive materials are presented. The unbalancing operation modes calculations in operating external and internal 0.38 kV electrical networks have been made, on the basis of which the proposed methodology has been tested. The technical means use effectiveness for the operating modes balancing in existing electrical networks with unbalance power consumption is proved.

Increasing energy and exergy efficiency in photovoltaic panels by reducing the surface temperature with thermoelectric generators

ABSTRACT Many factors affect the efficiency of photovoltaic panels (PV), which convert solar energy directly into electrical energy. Among these factors, temperature is one of the most important one. While some of the radiation from the sun is converted into electrical energy, part of it emerges as heat energy. This causes the photovoltaic cells to heat up and reduce their electrical efficiency. Different methods are used in the literature to reduce the temperature in PV panels. In this study, in order to reduce the adverse effects caused by the high temperature in the PV panels, 30 Thermoelectric Generators (TEG) were applied to the back surface of the PV panel to increase the PV panel output power and to produce additional electrical energy. Energy and exergy analysis made on the data obtained from both PV panels in the climatic conditions of the installation site showed that the temperature of the PV panel is reduced, and the energy and exergy efficiency is increased with the TEG application. At the end of July, August, and September, when the experiments were carried out, an average of 8.4% more electrical energy was obtained from a single PV panel with TEG, compared to the standard PV panel. Our results suggests that combination of TEG with PV panels could significantly increase the electrical energy, especially when a series of PV panels are used together.

Peramalan Jumlah Pelanggan PLN Menggunakan Simple Linear Regression

The rate of population growth in Lubuklinggau City continues to increase every year, this is a factor in the increasing demand for electricity. The development of the number of PLN customers in Lubuklinggau City in 2017 was 90.606 customers, increasing to 120.809 customers in 2021. PLN must be able to predict the number of electricity customers in the future in order to provide electricity needs. One of the forecasting models that can be used to predict the development of the number of PLN electricity customers is the Simple Linear Regression model. Simple Linear Regression is a forecasting model based on the effect of the causal variables on the effect variables. The variables used are the population variable and the number of PLN customers. From these two variables, the process of analyzing the influence of population on the number of PLN customers in the future will be carried out. The results showed that 90% increase in population affects the number of PLN customers. With the prediction of the development of the number of customers, PLN Lubuklinggau can prepare the necessary facilities and can estimate how much additional power and electrical energy will be in meeting customer needs in the future.

Rapid dehydrogenation of metallic materials under external electric field

The interaction between hydrogen and metal materials can lead to catastrophic failure of metallic materials, and while some metal materials can use this effect as hydrogen storage materials to make better use of hydrogen energy. If dehydrogenation is easier, it will help control hydrogen-induced degradation and the utilization of metallic hydrogen storage materials. In this study, molecular dynamics simulations are used to apply an electric field in the bicrystal hydrogen-iron system to study the diffusion coefficient of hydrogen atoms. Simultaneously, using hydrogen-charged high-strength as a model system, the effect of electric field on hydrogen content and mechanical properties of hydrogen-charged high-strength steel was also studied. Experimental and molecular simulation results show that, compared with traditional tempering, the diffusion rate of hydrogen atoms is faster and the diffusion activation energy is smaller under the action of an electric field, which is more conducive to the recovery of the mechanical properties of hydrogen-charged high-strength steel. Due to the introduction of an electric field to cause additional electrical energy, the energy barrier for hydrogen atom diffusion is lowered. At the same time, due to the influence of electromigration, the diffusion of hydrogen atoms is driven by an electron wind force, which eventually leads to an acceleration of the dehydrogenation rate.

The organic Rankine cycle: A promising technology for electricity generation and thermal pollution mitigation

Waste heat emissions derived from cooling systems of the thermal power plant often discharged into rivers, lakes and seas, have been the direct cause of environmental problems for marine life. To control these wastewater discharges into the receptor water body, government regulations have been created to act as limiting factors for additional power generation from these plants. The problem can be solved with an organic Rankine cycle (ORC), which is considered a promising technology in electricity generation and an alternative to avoid the thermal pollution of aquatic ecosystems. The present work analyzes the use of an ORC system aiming to increase the thermal and overall efficiency of conventional operating systems without causing an additional thermal impact on marine species. This evaluation was based on the first and second laws of thermodynamics, applied to seven organic fluids (toluene, methanol, benzene, R11, R12, R113, R134a) and equations that linked the overall efficiency of the power plant with parameters of life quality in the rivers. Results showed that among the chosen organic fluids benzene produced the highest thermal efficiency for the ORC. Besides, an application of the proposed modelling in a thermal power plant localized near to Tubarão river, SC – Brazil was presented. Results showed that by using R113 as working fluid, it is possible to generate up to 1365.02 kWelec of additional electrical energy and increase both thermal and overall efficiency of a thermal power plant by up to 22.34% and 11.01%, respectively, without causing a thermal impact on the aquatic ecosystem. The best energy use was achieved by the recuperative ORC configuration. The Dissolved Oxygen Concentration (DOC) was reduced to 6.14 %day−1, which is consistent with the regulation of the Brazilian government regarding effluent discharges in lagoons, rivers and seas. On the other hand, considering the electricity cost at 0.16 US$kWh−1 and 5% as an annual percentage rate (APR), results in a payback period of approximately 5.3 years. Thus, the specific investment cost (SIC) of this technology was estimated at 1314.57 US$kWe−1.

Spectral Changes by Dye Sensitized Solar Modules Influence the Pigment Composition and Productivity of Arthrospira maxima and Increase the Overall Energy Efficiency

AbstractThe integration of semi‐transparent photovoltaics (PVs) with photobioreactors (PBRs) is a promising strategy to increase photoconversion efficiency, ensuring simultaneous electricity and algal biomass production. In this study, Arthrospira maxima is cultivated in an integrated system with a dye‐sensitized solar module (DSSM) to the front of the PBR to assess the possible advantages for biomass and phycocyanin production. The application of the DSSM does not influence biomass production, with the remarkable advantage of producing additional electric energy. However, an acclimation of pigment is observed, as DSSM causes a change in the transmitted light spectrum. Further experiments are conducted to investigate the effect of light quality using monochromatic light‐emitting diodes (LEDs) as controls. Phycocyanin‐targeted wavelengths exhibit a major impact on biomass growth and pigment productivity: low intensity enhanced process efficiency, suggesting that low light is preferable to enhance culture performance with respect to white light. The application of third‐generation PVs is only potentially advantageous if the transmission spectra of the module color and its aperture area are carefully designed. The application of monochromatic LEDs on PBRs also highlights the importance of properly managing the operative conditions to avoid energy losses.

Performance and feasibility study of a new hybrid solar water heater integrated a small water turbine

AbstractThe production of thermal energy by solar water heater (SWH) systems is an idea, which has been analyzed and applied for many years. This paper presents a numerical simulation of a new hybrid SWH, in which two tubular thermoelectric generators (TTEGs) and a small water turbine are used to generate more additional electrical energy. The small water turbine is installed between the outlet of the four absorber tubes and the inlet of the water tank in order to generate more electrical energy from the cold‐water motion. Furthermore, the use of a temperature adjustment concept and an optical concentrator shows many significant improvements on the thermal and electrical performance of the new system. Our main results shows that the overall maximum electrical power of two TTEGs was approximately 348.073 W, corresponding to 2.72% of their overall maximum electrical efficiency. Also, the maximum thermal efficiency of the new system reached to 86.09% with an overall hot water quantity of 1548.57 L/d. The electrical energy produced by the small water turbine is about 89.467 W for a cold‐water flow rate of 3 kg/s.

Thermal Stability of Supercapacitor for Hybrid Energy Storage System in Lightweight Electric Vehicles: Simulation and Experiments

Recent research findings indicate that the non-monotonic consumption of energy from lithium-ion (Li-ion) batteries results in a higher heat generation in electrical energy storage systems. During peak demands, a higher heat generation due to high discharging current increases the temperature from 80 °C to 120 °C, thereby resulting in thermal runaway. To address peak demands, an additional electrical energy storage component, namely supercapacitor (SC), is being investigated by various research groups. This paper provides insights into the capability of SCs in lightweight electric vehicles (EVs) to address peak demands using the worldwide harmonized light-duty driving test cycle (WLTC) driving profile in MATLAB/Simulink at different ambient temperatures. Simulation results indicate that temperature imposes a more prominent effect on Li-ion batteries compared with SCs under peak demand conditions. The effect of the discharging rate limit on the Li-ion battery current is studied. The result shows that SCs can accommodate the peak demands for a low discharging current limit on the battery, thereby reducing heat generation. Electrochemical impedance spectroscopy and cyclic voltammetry are performed on SCs to analyze their thermal performance at different temperatures ranging from 0 °C to 75 °C under different bias values of −0.6, 0, 0.6, and 1 V, respectively. The results indicate a higher specific capacitance of the SC at an optimum operation temperature of 25 °C for the studied bias. This study shows that the hybrid combination of the Li-ion battery and SC for a light-weight EV can address peak demands by reducing thermal stress on the Li-ion battery and increasing the driving range.

Effective factors for the performance of a co-generation system for bioethanol and electricity production via microbial fuel cell technology

A co-generation system was designed to extract the redundant electrons generated in the biofermentation process to produce electricity and bioethanol simultaneously by using a microbial fuel cell (MFC) device. The effects of process operating parameters–methylene blue (MB) concentration, substrate concentration, temperature, and anodic pH on a co-generation system of ethanol and electricity were investigated to improve energy efficiency during ethanol fermentation. The results showed that a positive correlation between the power density of the co-generation system with substrate concentration and temperature was found over the range of 20–100 g/L and 25–35 ℃, respectively, in which ethanol was maintained at a high production level. The neutral or acid anodic solution was preferred for the co-generation system rather than the alkaline one when considering both power out and ethanol production. By assisting MFC technology, the total energy efficiency of fermentation was improved from 91.01% to 94.21% where 0.98% additional valuable electric energy was recovered. Yeast domestication is a promising way to enhance the power performance by increasing the tolerance of yeast to MB without reducing ethanol production. The proposed co-generation system indicates that the potential application of MFC in the production of biofuel or bioproducts efficiently and sustainably.

An environmental and economic evaluation of solar photovoltaic thermal dryer

The photovoltaic thermal (PVT)-based solar dryer is advantageous in terms of energy-saving ability, efficiency, self-sufficient design, and ability to work without any additional electrical energy requirement. However, there is a requirement for a comprehensive analysis of the energy, exergy, and environ-economic parameters for developing an efficient and sustainable PVT solar dryer. In this study, a PVT-based indirect mode solar dryer with forced convection has been fabricated and investigated in the environmental conditions of North-East India (Silchar latitude of 24.83°). Experiments have been performed to compare the drying characteristics of tomatoes with quality analysis under the open sun and solar drying conditions. A new mathematical drying model is proposed to predict the drying characteristics of tomatoes under both modes of drying. The average PVT dryer efficiency is 34.98%, higher than some of the published works of indirect mode solar dryers conducted under similar experimental conditions. The calculated values of drying effectiveness, collector efficiency factor, coefficient of performance, and heat utilization factor are 1.12–1.58, 0.011–0.029, 0.71, and 0.29, respectively. Furthermore, CO2 emission, CO2 mitigation and carbon credit earned parameters are evaluated for 10, 20, and 30 years of system life. Graphical abstract

An approach to increase the power output of Karnafuli Hydroelectric Power Station: A step to sustainable development in Bangladesh's energy sector.

Renewable energy has become the most prominent source of energy to reduce carbon emissions around the globe. Undoubtedly, hydro energy is very much clean energy among other sources. In Bangladesh, hydro energy is available only in a specific southern area contributing several hundred megawatts to the national grid. This paper devotes to assessing the capacity and practicability of a hydropower plant to boost the power output by implementing the combined cycle hydropower system. The proposed method has been developed by 1) studying the existing plant based on surveyed data, 2) selecting the site for installing the hydrokinetic turbine, 3) designing with consideration of numerous constraints of inter dependability, and 4) creating a prototype model to ensure the practicability. Preliminary results show that a significant amount of additional electric energy can be generated from the plant with higher efficiency.

Reduction of Energy Intensity in Broiler Facilities: Methodology and Strategies.

Broiler facilities consume a lot of energy resulting in natural source depletion and greater greenhouse gas emissions. A way to assess the energy performance of a broiler facility is through an energy audit. In the present paper, an energy protocol for an energy audit is presented covering both phases of data collection and data elaboration. The operational rating phase is analytically and extendedly described while a complete mathematical model is proposed for the asset rating phase. The developed energy audit procedure was applied to poultry chambers located in lowland and mountainous areas of Epirus Greece for chambers of various sizes and technology levels. The energy intensity indices varied from 46 to 89 kWh/m2 of chamber area 0.25–0.48 kWh/kg of produced meat or 0.36–1.3 kWh/bird depending on the chamber technology level (insulation, automation, etc.) and the location where the unit was installed. The biggest energy consumer was heating followed by energy consumption for ventilation and cooling. An advanced technology level can improve energy performance by ~ 27%−31%. Proper insulation (4–7 cm) can offer a reduction of thermal energy consumption between 10 and 35%. In adequately insulated chambers, the basic heat losses are due to ventilation. Further energy savings can be achieved with more precise ventilation control. Automation can offer additional electrical energy saving for cooling and ventilation (15–20%). Energy-efficient lights can offer energy saving up to 5%. The use of photovoltaic (PV) technology is suggested mainly in areas where net-metering holds. The use of wind turbines is feasible only when adequate wind potential is available. Solar thermal energy is recommended in combination with a heat pump if the unit's heating and cooling systems use hot/cold water or air. Finally, the local production of biogas with anaerobic fermentation for producing thermal or electrical energy, or cogenerating both, is a choice that should be studied individually for each farm.

Achieving High-Quality Freshwater from a Self-Sustainable Integrated Solar Redox-Flow Desalination Device.

Solar-assisted electrochemical desalination has offered a new energy-water nexus technology for sustainable development in recent studies. However, only a few reports have demonstrated insufficient photocurrent, a low salt removal rate, and poor stability. In this study, a high-quality freshwater level of 5-10ppm (from an initial feed of 10000ppm), an enhanced salt removal rate (217.8µg cm-2 min-1 of NaCl), and improved cycling and long-term stability are achieved by integrating dye-sensitized solar cells (DSSCs) and redox-flow desalination (RFD) under light irradiation without additional electrical energy consumption. The DSSC redox electrolyte (I- /I3- ) is circulated between the photoanode (N719/TiO2 ) and intermediate electrode (graphite paper). Two DSSCs in parallel or series connections are directly coupled to the RFD device. Overall, this hybrid system can be used to boost photo electrochemical desalination technology. The energy-water nexus technology will open a new route for dual-role devices with photodesalination functions without energy consumption and solar-to-electricity generation.

PRELIMINARY SUBSTANTIATION OF ADVANCED DIRECTIONS OF MODERNIZATION OF COAL-FIRED POWER PLANTS TO IMPROVE EFFICIENCY

The article considers issues related to the modernization of coal-fired power technologies. To increase the efficiency of energy resources, operational reliability, loss reduction and environmental safety the possibilities of trigeneration are considered with application of fuel cells, hydrogen technologies and RE-components that are expedient to use for additional electric energy production. The possibilities of innovative energy components to integrate them into traditional power generation systems are shown, technological schemes are given.

Asymmetric power consumption in rural electric networks

Study of changes in quality indicators and an increase in additional losses of electrical energy in rural distribution networks of 0.38 kV in the village (Vishnyakovo, Irkutsk region). The measurements were carried out by a certified device “Resource-UF2M”, which records changes in the quality indicators of energy efficiency, but does not record additional losses of electrical energy associated with this changed quality. Therefore, based on the obtained measurement data, we used the developed computer program “Asymmetry” to calculate the required power quality indicators, as well as additional electrical energy losses caused by a change in these indicators. Based on the results of measurements and calculations, time diagrams were built, and an analysis was made of quality indicators and additional losses of electric energy in the existing 0.38 kV networks.

Enhancement of efficient and selective hydrolysis of maize starch via induced electric field

This study aimed to efficiently and selectively hydrolyze maize starch via induced electric field (IEF). The role of electrical conductivity in regulating hydrolysis efficiency and selectivity was investigated, and the structural and physicochemical properties of hydrolyzed products were characterized. Compared with water-bath heating, IEF induced the rapid and ordered migration of charged species, thus increasing the hydrolysis rate and narrowing the molecular weight distribution of hydrolyzed starch. The addition of KCl enhanced IEF-assisted hydrolysis due to the absorption of additional electrical energy into the reaction system. After hydrolysis, the molecular chains of maize starch exhibited cleavage, the granular surface became rough, the crystallinity increased, the gelatinization enthalpy slightly increased, the viscosity of starch paste reduced, the hardness of starch gel declined, and the re-crystallization showed no significant improvement. Overall, this study extends the potential applications of electro-techniques in preparing hydrolyzed starch with narrow molecular weight distribution in food and material fields.

Особенности применения ОЦР-технологии на компрессорных станциях металлургических предприятий

The use of secondary energy resources in metallurgy with their conversion into mechanical and / or electrical energy allows not only to reduce the negative impact on the environment, but also to significantly increase the energy efficiency of facilities. As a result the study design, the results of which are presented in this article defined the energy-saving potential at the compressor station metallurgical enterprises (on the example of the system of supply of technical gases of the process of production of rolled steel from iron ore PJSC Magnitogorsk Iron and Steel Works). A schematic solution and a method for determining the operating parameters of an installation operating according to the so-called "organic Rankine cycle" (ORC installation), which allows obtaining additional electrical energy for production needs by utilizing the heat of interstage cooling of compressor units, are proposed and justified. The features of the implementation of this technology are identified, and the working substance of the ORC installation that meets the requirements of safety and energy efficiency as much as possible is proposed for implementation. The values of the internal efficiency, the power of the ORC installation and the share of usefully utilized heat in the implementation of the proposed scheme are estimated.

Benefit Assessment of Skidder Powertrain Hybridization Utilizing a Novel Cascade Optimization Algorithm

Over the last decade, off-road vehicles have been increasingly hybridized through powertrain electrification in terms of additional electrical machine-based propulsion and battery energy storage, with the goal of achieving significant gains in fuel economy and reductions in greenhouse gases emissions. Since hybrid powertrains consist of two or more different energy sources and may be arranged in many different configurations, there are many open questions in their design and powertrain energy management control, which may have influence on the hybridized powertrain purchase cost and efficiency. This paper presents simple backward optimization models of conventional and hybrid cable skidder powertrains. These models are then used in the optimization of control variables over one forest path in order to find the minimum possible fuel consumption. The optimization results show that 15% fuel efficiency improvement in winching and skid trail driving can be achieved with the selected hybrid powertrain. With that improvement, main hybrid drive components can be paid off in 13 years.