Electricity Generation Performance Research Articles

Experimental and numerical study on performance enhancement of photovoltaic panel by controlling temperature with phase change material

In order to enhance the electricity generation performance of photovoltaic (PV) panel, experimental and numerical studies were carried out to control the temperature by using phase change material (PCM). The PV combined with PCM (PV-PCM) device and PV-PCM with foam copper were designed, and their temperature, voltage, and output power were measured and compared with those of PV panel. The mathematical model of heat transfer for PV-PCM was established and verified by experiment. And the influences of PV-PCM tilt angle, PCM properties and thickness, and ambient temperature on the temperature control effect were studied numerically. The results illuminate that the PV panel's temperature decreases significantly with the using of PCM, which correspondingly enlarges its open circuit voltage and output power. And the PCM with foam copper has a better effect. The temperature control effect of the PV-PCM system is better with the increase of the tilt angle, the PCM thermal conductivity and thickness, and the decrease of PCM phase change temperature. But there are limited conditions for them. The higher the ambient temperature, the worse the temperature control effect. The present study has important reference value for PV performance enhancement.

Effects of cathode/anode electron accumulation on soil microbial fuel cell power generation and heavy metal removal

Microbial fuel cells (MFCs) with different electrode configurations were constructed to study the mechanism of influence of multiple current paths on their electrical performance and the removal of heavy metals in soil. Three types of MFCs were constructed, namely, double anode–single cathode (DASC), single anode–dual cathode (SADC), and single anode–single cathode (SASC). The total electricity generation of the three kinds of MFC was similar: 143.44 × 10–3 mW, 114.90 × 10–3 mW, and 132.50 × 10–3 mW, respectively. However, the maximum voltage and cathode current density produced by a single current path differed significantly. The corresponding values were 0.27, 0.23, and 0.42 V and 0.130, 0.122, and 0.096 A/m 2, respectively. The SASC had the best electricity generation performance. Based on a limited reduction rate of oxygen at the cathode, the accumulation of cathode electrons was facilitated by the construction of multiple current paths in the MFC, which significantly increased the cathode electron transfer resistance and limited the electricity generation performance of the MFC. However, at the same time, the construction of multiple current paths promoted output of more electrons in the anode, reducing the retention of anode electrons and anode electron transfer resistance. The heavy metal removal efficiencies of SASC, DASC, and SADC were 2.68, 2.18, and 1.70 times that of the open circuit group, respectively. The migration of heavy metals in the soil depended mainly on the internal electric field intensity of the MFC rather than the total electricity generation. As the internal electric field intensity increased, the removal efficiency of heavy metals in the MFC increased.

Simultaneous removal of copper and biodegradation of BDE-209 with soil microbial fuel cells

The microbial fuel cells (MFCs) were developed in the present study to remove copper (Cu) and decabromodiphenyl ether (BDE-209) from an artificially contaminated soil. The performance of electricity generation, BDE-209 degradation and Cu removal were investigated. Soil enzyme activity, BDE-209 mineralization and microbial community structures were analyzed. Experimental results showed that the removal of BDE-209 and Cu was effectively enhanced by the application of soil MFCs. After 60-day MFC operation, total Cu was removed by 69.2%, 66.4% and 62.5% for an initial Cu content of 250, 500 and 1000 mg/kg, respectively. More than 80% Cu removed was transformed to pure copper and deposited on the cathode plates. Soil enzyme activity and BDE-209 removal (85.5%) were both highest in the case of 500 mg/kg Cu. Genomic sequencing results indicates that electrogenic and debromination bacteria survived together in the soil MFCs. The MFC operation promoted the growth and reproduction of electrogenic bacteria. These results demonstrate that the soil MFCs can be employed as a durable and effective approach for detoxicating organic-metal co-contaminated soil.

Effect of Polypyrrole-Fe3O4 Composite Modified Anode and Its Electrodeposition Time on the Performance of Microbial Fuel Cells

Anode modification is a useful method to increase the performance of microbial fuel cells (MFCs). By using the electrochemical deposition method, Fe3O4 and polypyrrole (PPy) were polymerized on a carbon felt anode to prepare Fe3O4-PPy composite modified anodes. In order to ascertain the effect of electrodeposition time on characteristics of the modified electrode, the preparation time of the modified electrode was adjusted. The modified anodes were used in MFCs, and their performances were evaluated by analyzing the electricity generation performance and sewage treatment capacity of MFCs. Experimental results indicated that the Fe3O4-PPy composite modified anodes could enhance the power production capacity and sewage treatment efficiency of MFC effectively. In particular, when the deposition time was 50 min, the modified anode could significantly improve the MFC performance. In this case, the steady-state current density of MFC increased by 59.5% in comparison with that of the MFC with an unmodified carbon felt anode, and the chemical oxygen demand (COD) removal rate was 95.3% higher than that of the unmodified anode. Therefore, the Fe3O4-PPy composite is an effective material for electrode modification, and a good anode modification effect can be obtained by selecting the appropriate electrodeposition time.

Effect of Vertical Permeability Heterogeneity in Stratified Formation on Electricity Generation Performance of Enhanced Geothermal System

Because geologic sedimentation and hydrofracturing processes are not homogeneous, the reservoirs of enhanced geothermal systems (EGSs) are also heterogeneous; this has a significant influence on the electricity generation performance of EGS. Presently, there are a lack of systematic and profound studies on the effect of vertical permeability heterogeneity in stratified formation on the electricity generation performance of EGS. In order to uncover the effect of vertical permeability heterogeneity on electricity generation performance of EGS, in this work we analyzed the influence of vertical permeability heterogeneity on electricity generation performance of EGS through a numerical method based on geological data at the Yangbajing geothermal field. The results indicate that when the average permeability of stratified formations is constant for a homogeneous reservoir, the system attains maximum water production rate, maximum electric power, minimum reservoir impedance and maximum pump power; with the increasing of the vertical permeability heterogeneity, the water production rate gradually decreases, the electric power gradually declines, the reservoir impedance gradually increases and the pump power gradually declines. When the average permeability of stratified formations is constant, with the increasing of the vertical permeability heterogeneity, the injection pressure and energy efficiency only changes very slightly; this indicates that the vertical permeability heterogeneity is not the main factor affecting the system injection pressure and energy efficiency.

Using a three-dimensional hydroxyapatite/graphene aerogel as a high-performance anode in microbial fuel cells

Bioaffinity of anode materials is a key factor for the power output of microbial fuel cells (MFCs). Anode surfaces with excellent biocompatibility can facilitate bacterial adhesion, biofilm propagation, and extracellular electron transfer. In this study, three-dimensional (3D) hydroxyapatite/graphene aerogel (HA/GA) was synthesized using a facile three-step method: hydrothermal treatment, dialysis, and freeze-drying. The HA/GA anode presented the excellent biocompatibility of HA and high conductivity of graphene. Moreover, the unique edge-to-edge cross-linked architecture of the HA/GA offered a large surface area for bacterial adhesion. Shewanella putrefaciens can generate more flavins through the introduction of highly biocompatible HA nanocrystals on the graphene sheets, leading to a rapid extracellular electron transfer between the biofilm and anode. An MFC containing a HA/GA anode delivered a maximum power density of 2.38 W m− 2, which was 1.83 times the power density achieved using a GA anode. Furthermore, MFCs equipped with HA/GA anodes were successfully utilized to drive a series of electrical appliances. The HA/GA anode possessed excellent biocompatibility, large surface area, superior hydrophilicity, and high conductivity, which were conducive for enhancing the surface bioaffinity and accelerating the interfacial charge transfer, thereby improving the electricity generation performance of the MFCs. This study has proven that HA is beneficial for enhancing the interface bioaffinity and that it can be applicable to MFC for high-performance bioelectricity harvesting.

Implementação de sistema inteligente de aquisição de dados com indicadores de desempenho para miniusina solar fotovoltaica / Implementation of intelligent data acquisition system with performance indicators for solar photovoltaic mini-plant

The electricity generation performance in a photovoltaic system can be improved by precise monitoring of electrical and meteorological parameters. Disruptions in electrical parameters are caused by unreliable climatic variables, degradation of the photovoltaic system, and errors. The main purpose of the present work is the development of a data acquisition and monitoring system for time series data storage for subsequent analyses of the solar photovoltaic mini-plant located at the Poços de Caldas campus of the Federal University of Alfenas. The developed system exhibits the collected parameters as well as the performance metrics calculated by numerical modeling. For this purpose, a data logger, web server, REST API and a responsive web application were created.

Investigation of electricity generation performance of grape marc in membrane-less microbial fuel cell

Grapes are among the most widely grown fruits globally, with a third of the overall production used in winemaking. Both red and white winemaking processes generate significant amounts of solid organic waste such as grape marc that requires proper disposal. Grape marc, a natural plant product containing abundantly lignocellulosic compounds, is a promising raw material for production of renewable energy. In this study, the grape marc was used as an anode nutrient in the membrane-less microbial fuel cell (ML-MFC) system, and the electricity generation capacity of the grape marc as an environmentally friendly energy source was investigated in detail. The maximum power density produced in the ML-MFC reactor was determined as 274.9 mW m-2, and the total internal resistance was 309.5 Ω. Cyclic voltammetry results showed the presence of electroactive microorganisms on the surface of the anode electrode provided a high biological activity. The presence of elliptical and round-shaped microorganisms on the anode electrode surface was observed. Quantitative polymerase chain reaction (qPCR) analyzes have shown that grape marc supports bacterial growth on the electrode surface.

Solid Oxide Fuel Cells Fueled with Biogas in Malaysia: A Review of Potential

The limitations of conventional energy resources have encouraged worldwide research on various types of energy in electricity generation. Fuel cell-based electricity generation creates a huge potential in the energy industry. This paper aimed to study the potential of biogas in Malaysia to be fed into the direct biogas solid oxide fuel cell (DB-SOFC) system. The data obtained from the Malaysian Palm Oil Board (MPOB), Energy Commission (ST) and Department of Statistics Malaysia were used in this study. The analysis showed that in 2019, Malaysia had the potential to generate biogas of about 877.53 million m3/year. The characterisations of the DB-SOFC system with a capacity of 200 kW from Bloom Energy were applied in this study. The result indicated that Malaysia’s potential to generate about 2006.9 MW of electricity from biogas solid oxide fuel cells was approximately 6% of the total electricity capacity in the country. When compared with the conventional biogas’ combined production of heat and power (CHP), the DB-SOFC gave 76.95% more performance in electricity generation. Therefore, this study finding provides a positive impact on the biomass industry in Malaysia. Extensive research and development (R&D) are needed in order to penetrate this fuel cell system into Malaysia’s energy industry landscape.

In-situ alkaline pretreatment of waste activated sludge in microbial fuel cell enhanced power production

Energy recovery from waste activated sludge (WAS) by microbial fuel cell (MFC) can simultaneously address energy issue and environmental concerns. Pretreatments are vital to enhancing energy recovery and sludge reduction with WAS as power source in MFC. The commonly applied two-stage process, which separates WAS pretreatment with electricity generation, decreases the cost-effectiveness of MFC with WAS as power source. It is of great practical importance to investigate the feasibility of one-stage process for simultaneous sludge pretreatment and electricity generation. Herein, a one-stage alkaline MFC (anode chamber controlled at pH 9.0) is constructed to recover energy from in-situ alkaline pretreated WAS. Results show that alkaline MFC achieves excellent performance of electricity generation with high voltage output (0.74 V) and high power density (0.65 W m−2). The total chemical oxygen demand removal of WAS is >40%. No greenhouse gas (CH4 and CO2) are released from the alkaline MFC with WAS as power source. The enhanced electricity generation performance in the alkaline MFC is investigated through three aspects, including internal resistance, degradation of soluble organics, and shift of microbial community. This work offers a promising alternative for energy recovery with WAS as renewable power source.

Numerical Investigation of the Effect of Cooling and Heating Conditions on the Performance of Thermoelectric Module

Today, the need for energy increases, and fossil fuel resources run out rapidly so energy costs also increase rapidly. The most important feature of fossil fuels is that they consist of hydrocarbon and organic substances containing high levels of carbon. This causes great harm to the world and humanity. In the face of this dangerous situation, world states look for new and clean energy sources. As a result, the trend towards renewable energy sources increases rapidly. In this context, TE (thermoelectric) module is an important source to convert heat to electrical energy. The amount of electricity generation from heat depends on the temperature difference between surfaces of the TE module. The electrical power obtained from heat increases with the increase of temperature difference. This work aims to investigate numerically the heat transfer and electricity generation performance of a 〖Bi〗_2 〖Te〗_3-based TE module embedded with cylindrical pin-fin heat sink under the different hot surface and air temperature conditions with different air velocities. The results were evaluated and discussed with parameters such as temperature distribution, power input, power output, voltage output, current output, temperature difference, total thermal resistance, conversion efficiency and Nusselt number according to Reynolds numbers. In all analyses, it was observed that performance of the heat transfer and electricity generation of the TE module increase with the increase in Reynolds number. The highest conversion efficiency was obtained generally at surface temperatures of 200℃, specifically at air temperature of 5℃ and the Reynolds number of 20000. In addition, it was observed that the temperature difference between the surfaces of the TE module is not sufficient alone to give good performance and besides, it is necessary to keep the cold surface at low temperature.

Long-term electricity generation and denitrification performance of MFCs with different exchange membranes and electrode materials

Different biocathode electrode materials (graphite felt and carbon brush, GF and CB) and exchange membranes (proton exchange membrane and cation exchange membrane, PEM and CEM) were used in three microbial fuel cell (MFC) configurations operated for 300-days to investigate the power generation and the COD and N removal performance. Results showed no effect on the COD removal (all above 96%); however, the power generation (46.11 mW·h) and denitrification performance (68.0 ± 1.6%) of the MFC-B (GF + PEM) system were higher than those of the other systems (MFC-A: CB + PEM; MFC-C: CB + CEM) (P < 0.01), and the power generation and denitrification performance of all three systems decreased with time (P < 0.01). By analyzing the physicochemical properties of the exchange membrane and cathode electrode materials, the reasons that affect the power generation performance of the system were clarified. Furthermore, the increase in bioelectricity enhanced the electricity-related nitrification and denitrification reactions. The average 300-day unit denitrification cost of MFC-A was 4.2 and 6.3 times that of MFC-B and MFC-C, respectively. Comprehensive consideration of electricity generation, denitrification, and service life, combined with cost analysis and better selection of construction materials, provides a theoretical basis for the long-term stable operation and sustainable application of MFCs.

Excellent high-temperature piezoelectric energy harvesting properties in flexible polyimide/3D PbTiO3 flower composites

Piezoelectric nanogenerators (PENGs) have been paid great attention in powering electronics via harvesting mechanical energy. Presently, increasing lights are shed onto flexible PENGs capable of working at harsh temperatures. In this research, we report a synthesis of 3D hierarchical PbTiO3 flower-like structure (PTFs) and polyimide (PI)/PTFs composites from which PENGs with excellent high-temperature energy harvesting performances are fabricated. PTFs exhibit a pure phase and a 3D architecture obtained by the hydrothermal method. The PI/PTFs composite PENGs exhibit good electricity-generation performances of Voc ~ 140 V, Isc ~ 103 μA and P ~ 2128 μW. Moreover, high degree of electric power can be continuously generated by the PENG at a wide range of temperature from room-temperature to 300 °C. Excellent durability up to 5000 cycles can be also obtained for the PENG within the temperature range. It has been demonstrated that a PENG in this study lights fifty light-emitting diodes and the resulting electricity is successfully stored in a capacitor. In addition, a real-time high-temperature application is presented where harvesting electricity via the vibration energy of the running automobile engine occurs. The outstanding piezoelectric performance of PENG in this study is attributed to the thermal stability of PI and PT materials, and unique 3D architectures of PTFs in the composites. This work reveals a PI/PTFs composite based PENG exhibiting excellent energy harvesting properties at high-temperatures and the potential applications as microenergy harvesters.

A highly efficient organic solar energy-absorbing material based on phthalocyanine derivative for integrated water evaporation and thermoelectric power generation application

The 4OCSPC solid has a wide absorption range from 300 to 1000 nm and the solar-thermal conversion efficiency is evaluated to be 17.3%, which can attain superior water purification and electricity generation performances.

Effects of carbon-nitrogen ratio on electricity generation, pollutant removal and microbial community structure of single-chamber MFCs in high salinity wastewater

In this study, five sets of single-chambered air cathode microbial fuel cells (MFC) were constructed. The effect of the carbon-nitrogen ratio on electricity generation and pollutant removal was discussed and the dominant strains in electrode biofilms were analyzed by high-throughput sequencing. The results showed that in terms of electricity generation performance, the increase of the carbon-nitrogen ratio was beneficial to the energy output at the carbon-nitrogen ratio of 3∶1, 4∶1, 5∶1, 6∶1 and 7∶1. When the carbon-nitrogen ratio was 7∶1, the open circuit voltage, internal resistance and maximum power density were 765 mV, 78.4 Ω and 7.33 W·m−3, respectively. Single-chamber MFCs could achieve simultaneous nitrification and denitrification, and the best removal effect of pollutants occurred at the carbon-nitrogen ratio of 4∶1, the corresponding removal rates of COD, ${\rm{NH}}_4^ + $ -N and TN were (86.17± 2.4)%, (96.98±1.8)% and (96.64±1.8)%, respectively. Microbial sequencing results showed that Thauera was the core genus of single-chamber MFC. With the increase of carbon- nitrogen ratio, the abundances of heterotrophic nitrification microorganisms in the cathode biofilms were 35.72%, 46.90%, 40.17%, 35.63% and 21.38 % in turns. The abundances of aerobic denitrifying bacteria were 35.72%, 52.60%, 49.59%, 45.08% and 21.38%, respectively. It is speculated that the heterotrophic nitrification-aerobic denitrification was the main pathway for nitrogen removal.

Ti3C2 supported transition metal oxides and silver as catalysts toward efficient electricity generation in microbial fuel cells

The improved electricity generation performance of MFCs could be attributed to the Ti3C2 support and the synergistic effect between transition metal oxides and silver for ORR.

A Detailed Analysis of Daily, Seasonal and Yearly Performance Values of Photovoltaic Modules Using by a Simplified Method

The performance of panels for PV system design is determined according to the performance values in standard test conditions specified in the panel catalog, without knowing the performance under actual operating conditions. However, the operating performance of the PV panel depends on meteorological characteristics of place where the PV system is installed. Especially, if outside temperature values are above test conditions, the efficiency of the PV panel decreases and generation losses are observed. In this study, performance parameters of photovoltaic panel were calculated for four different PV panel technologies only by using their catalogue values like NOCT temperature, power-temperature coefficient etc. For this purpose, real working conditions were simulated using 3-year climate data for the meteorological conditions of Sanliurfa, Turkey. In the end, PV panel efficiency, electricity generation values and performance ratios were calculated in accordance with the temperature. According to the results obtained, the PV panels’ performance ratios decreased up to 0.75 during the summer months. The highest unit energy generation was achieved with thin film PV technology.

Moist-Induced Electricity Generation by Electrospun Cellulose Acetate Membranes with Optimized Porous Structures.

Harvesting energy from moist in the atmosphere has recently been demonstrated as an effective manner for a portable power supply to meet the ever-increasing demands of energy consumption. Porous materials are shown to have great potential in moist-induced electricity generation. Herein, we report moist-induced electricity generation by electrospun cellulose acetate (CA) membranes with optimized porous structures. We show that the pore size and porosity of CA membranes can be readily tuned via a facile compression and annealing process, and the effect of pore features on the output voltages can thus be investigated systematically. We find that, at a relatively high porosity, the electricity-generation performance can be further enhanced by constructing a smaller pore to form more nanochannels. Porous CA membranes, with an optimized porosity of 52.6% and a pore diameter less than 250 nm, are prepared to construct moist-induced electricity generators, which can be applied as breath sensors and can power up calculator operation. The current study provides insights for the construction of porous materials with different pore characteristics for moist-induced electricity generation, especially in the exploration of more efficient and low-cost porous materials for large-scale practical application of the portable power supply.

Manufacturing deformation impact on the performance of electrical generator for the wind turbine application

The system of systems approach is the representation of several distributed and independent systems, for a larger and complex system. The system can be defined as interacting and interdependent components forming a complex system. System perspective considers every single stator bar as a complex system, made up of several component strands and vent tubes. Strands are interacting and interdependent in orientation, to cancel out unbalanced strand voltage and minimizing circulating current. Visualizing the electrical generator with the system approach, the issue of incorrectly aligned interdependent and interacting components of the system has been noticed. The study presents the effective flux calculation due to strand tilt, and a nondestructive testing technique to measure the strand tilt. This paper first time presents a unique system perspective of the electrical generator; this would open further dimensions of system research, in electrical rotatory machinery and beyond.

Aerodynamic performance improvement using a micro-cylinder as a passive flow control around the S809 airfoil

Aerodynamic performance improvement of airfoilsis the first step towards enhancement ofthe wind turbine performance in electricity generation and energy conversion inrenewable energy applications. The flow behavioraround wind turbine blades profilecan be improved by introducing active and/or passive flow controls. This work numerically describes the impact of adding micro-cylinder, as a passive flow control around S809 airfoil, on aerodynamic performance under various operating conditions. A suitable combination of flow analysis and optimization technique has been used in the current work.The numerical simulation has been performed using ANSYSFluent 18.2 software. The airfoil was numerically analysed in flow atReynolds number of 106; aerodynamic coefficients (lift and drag coefficients) at different angle of attacks were validated with the experimental data reported by Somers in NREL. The Response Surface Method (RSM) is applied to obtain the optimum position of micro-cylinder to achieve maximum lift to drag ratio. It has been found that the total aerodynamic forces are sensitive to the location of the micro-cylinder. A significant enhancement of lift to drag ratio can be achieved by adding micro-cylinder in front of S809 airfoil especially at high Reynolds number.