Solar Power Sources Research Articles

(Invited) High-Energy-Density Redox-Flow Batteries: Fundamental Redox Processes and Materials Design Strategies

Energy storage system is a critical enabling factor for deploying unstable and intermittent renewable power sources such as solar and wind power sources. Redox flow batteries (RFBs) offer unique advantages of high efficiency, low cost, scalability and rapid response for grid energy storage. One of the most critical bottlenecks of RFBs is their low energy density, which is strongly related to the cell voltage and the solubility of the active materials. In this presentation, we will discuss strategies to improve the energy density of aqueous and nonaqueous RFBs and spectroscopic investigation on the redox processes involved in these RFB systems. Design strategies including redox complexing agent (e.g. lithium iodide, lithium bromide), semi-solid approach (e.g. sulfur/C and organic molecules), self-mediation approach, and highly-concentrated organic molecules (e.g. ferrocene-based) will be discussed. The influence of flow rate and current density on the electrochemical performance under continuous/intermittent flow modes as well as the synergistic interplay between solvent and redox-active materials in solid and liquid phases will be discussed. Acknowledgement: This work was fully supported by a grant from the Research Grant Council of the Hong Kong Special Administrative Region, China (Project No. T23-601/17-R).

Wide‐area damping controllers of wind and solar power using probabilistic signal selection

Recently, renewable energy sources such as wind turbines and solar photovoltaics have been increasingly applied in power systems to support inflated load demands. These renewable sources may be placed at locations that provide higher controllability of inter-area oscillations than those of conventional synchronous generators. Thus, an improved damping effect from such renewables can be expected. On the other hand, the signal selection of the wide-area damping controller (WADC) is normally conducted at an operating point. The strength of the input–output pairs of the WADC will consequently change according to the system operations. This study presents a WADC of wind and solar power sources using probabilistic signal selection. After selecting the most suitable input–output pairs, the control parameters of WADC are optimised using a robust control strategy and multiple-pole placement at several operating points. The designed WADC is evaluated by small-signal and transient stability studies in the IEEE 50-machine 145-bus system to guarantee the stabilising effect of the proposed WADC of wind and solar compared to that of the conventional WADC of synchronous generators.

Autonomous coop cooling system using renewable energy and water recycling

Extreme temperature in a chicken coop can significantly affect the growth and productivity of poultry. Therefore, the temperature inside the chicken coop need to be controlled to protect it from extreme temperatures. Most of the technology use electrical energy supplied to an evaporative cooling system to control the temperature of a coop. This paper presents an autonomous chicken coop cooling system using renewable energy and water recycling (REMACT). In this study, a monitoring system with necessary hardware, control application, powered with solar power source and water recycling, has been developed. The proposed cooling system consists of hardware part such as an Internet of Things (IOT) controller platform, temperature sensor, solar panel, water pump, water storage, water drain and pipe. When the temperature sensor detects extreme temperature more than 28℃ in a chicken coop, the water in storage tank will flow throughout the pipe and pass into water pump before it irrigates the chicken coop roof. When the temperature is below 22℃, the bulb will light up to transfer heat to the chicken coop and cause the temperature drop back to a healthy range. The water drain that is attached to the roof will collect the water and return the water back to the water storage again. The software components required by the project are Arduino IDE, Thinger.io, and Android Studio Framework. Several experiments have been conducted with hot and cold scenarios. The system was able to stabilise the temperature back to a healthy range. A usability testing result demonstrates 80% satisfactory rate. The findings from the experiments show that IoT, renewable energy and water recycling have the potential for temperature control of a chicken coop.

Design, Analysis and Development of Solar-Powered Electric Bi-Cycle for domestic use

Nowadays a greater number of people use cars or other automobiles as a means of transportation between places and the number of such vehicles is increasing day by day on the roads. Moreover, people are driving their cars for every need even if the location he/she is heading to is really near and can be taken by a walk. On the other hand, with respect to different researches that driving cars is having an impact on the environment and it is affecting the ozone layer due to the emission of greenhouse gases from the vehicles so providing a transport that supports the environment such as solar-powered e-bike is an affordable solution for our society particularly for the near distances. This paper presents the design and development aspects of solar powered bi-cycle. The key phases of this work include designing a solar energy cell converting solar energy into useable electric energy and designing a power transmission system suitable for driving a conventional bi-cycle. These phases involve calculation of power requirements to drive the bi-cycle and redesign of transmission elements of bi-cycles suitable to the solar energy power source and suitably select PV cell components to meet these requirements. The electrical motor type and capacity are decided on the basis of the above calculations and the motor is connected to the bi-cycle through suitable chain drive system. Solar PV cell capacity of 40 W with area dimensions of 54 x 51 cm is used to generate electrical energy and the same is used to charge the batteries as well. The maximum voltage recorded is 24 volts and the maximum current generated is 12 Amperes. Various parts of the assembly are integrated into the bi-cycle and the working model was completed. Finally, the testing of the bi-cycle was performed to obtain the results based on which an engineering analysis and cost details were carried out. The fabricated model and the results obtained thus prove that there is a potential scope to introduce the solar-integrated electric bikes into the market for domestic use.

Design, Analysis and Development of Solar-Powered Electric Bi-Cycle for domestic use

Nowadays a greater number of people use cars or other automobiles as a means of transportation between places and the number of such vehicles is increasing day by day on the roads. Moreover, people are driving their cars for every need even if the location he/she is heading to is really near and can be taken by a walk. On the other hand, with respect to different researches that driving cars is having an impact on the environment and it is affecting the ozone layer due to the emission of greenhouse gases from the vehicles so providing a transport that supports the environment such as solar-powered e-bike is an affordable solution for our society particularly for the near distances. This paper presents the design and development aspects of solar powered bi-cycle. The key phases of this work include designing a solar energy cell converting solar energy into useable electric energy and designing a power transmission system suitable for driving a conventional bi-cycle. These phases involve calculation of power requirements to drive the bi-cycle and redesign of transmission elements of bi-cycles suitable to the solar energy power source and suitably select PV cell components to meet these requirements. The electrical motor type and capacity are decided on the basis of the above calculations and the motor is connected to the bi-cycle through suitable chain drive system. Solar PV cell capacity of 40 W with area dimensions of 54 x 51 cm is used to generate electrical energy and the same is used to charge the batteries as well. The maximum voltage recorded is 24 volts and the maximum current generated is 12 Amperes. Various parts of the assembly are integrated into the bi-cycle and the working model was completed. Finally, the testing of the bi-cycle was performed to obtain the results based on which an engineering analysis and cost details were carried out. The fabricated model and the results obtained thus prove that there is a potential scope to introduce the solar-integrated electric bikes into the market for domestic use.

Design validation and analysis of the drive range enhancement and battery bank deration in electric vehicle integrated with split power solar source

Solar panels are prominently incorporated into electric vehicle rooftop to charge the battery bank. In this paper, the analytical design of two solar electric vehicle models powered with split power solar source architecture and conventional solar power source architecture are presented. The operational behavior of the analytically designed solar electric vehicle models is validated using Matlab. The superiority between split power solar source and conventional solar power source in terms of power contribution capability to the electric vehicle battery bank is analysed under real-time conditions using PVsyst real-time simulator. Further, the drive range enhancement and battery bank deration rate in the two solar EV models due to the incorporation of solar power source is analysed and compared for real-time conditions. Finally, the results of the superior solar electric vehicle model are validated through experimental construction and testing of the model. The comparative study concludes that solar electric vehicle model powered with split power solar source architecture is the best in terms of maintaining battery performance, power contribution capability and drive range enhancement.

Forecasting Analysis Based on Multi-scale and Multi-time with Uncertainty

Abstract The dissemination of distributed resources presents a new paradigm for the power industry. Especially solar power is creating a new chapter for trading electricity as a new source. Solar power sources and load resources are each uncertain by their size and time factors. This paper discusses the uncertainties due to the accuracy of the forecast by forecasting PV power source and by forecasting load resource based multi-scale and multi-time. To do this, artificial neural networks are used to forecast these resources at a different time interval and the amounts by aggregation. Uncertainty from the forecasting results is discussed.

INTELLIGENT RESIDENTIAL ENERGY MANAGEMENT SYSTEM IN SMART BUILDING CONSIDERING FUEL CELL AND PHEV’S

The increased greenhouse gas emissions and the global warming from fossil fuels to produce electrical power generation and transportation, they become the most critical concern of governments to find an alternative source to fossil fuels such as renewable energies like wind and solar; Additionally, transportation is one of the main sources of environmental pollution, to this end, PHEV grid is presented, but the widespread use of PHEV will be creating a significant load on the grid. For this reasons in this paper, a model for the optimal application of green house, was studied in 24 hours. Energy management issue is considered in zero energy buildings with solar hybrid power sources, fuel cell, electrolyzer, hydrogen tank, compressor, reformer, anaerobic reactors and converters as well as plug-in hybrid electric vehicle (PHEV) must be provided, designed and implemented. The green house serves bilateral energy exchange with the upstream distribution network and if the surplus energy provided, can be sold to the network. Daily house trashes use to decline the bioenvironmental contaminations and also heat of house and hot water is supplied using fuel cell heat and if necessary we should purchase gas from network. In order to optimize this house, an objective function is extracted and aggregation Swarm algorithm to minimizing costs was carried out using MATLAB program. Finally, optimal operation is presented for the green house and results have been analyzed.

Lamination-produced semi-transparent/flexible perovskite solar cells with doped-graphene anode and cathode

Semi-transparent flexible perovskite solar cells (FPSCs) are highly attractive for effective use of solar energy in many areas such as building- and vehicle-integrated photovoltaics. High power conversion efficiency (PCE) of perovskite solar cells is achieved mainly by using transparent conductive oxide electrodes, which are unsuitable for FPSCs. Here, we first report semi-transparent and high-aperture FPSCs with anode/cathode electrodes fabricated by doping of graphene (GR) with bis (trifluoromethanesulfonyl)-amide (TFSA) and triethylenetetramine (TETA), respectively. The FPSCs are fabricated by laminating the polyethylene terephthalate (PET)/TETA-doped GR (TETA-GR)/ZnO/MAPbI3/poly-triarylamine and the PEDOT:PSS/TFSA-doped GR (TFSA-GR)/PET stacks. PCEs of 10.56/10.73% are obtained by illumination at the TFSA-GR/TETA-GR sides of the FPSCs with an active area of 100 mm2, respectively. The PCE is further enhanced to 10.96/11.16% by adding Ag reflectors at the top/bottom of the FPSCs, respectively. In addition, the PCE is maintained at 70% or more of its original value even after 1000 bending cycles at a bending radius of 8 mm, promising for practical applications of the FPSCs as next-generation semi-transparent solar energy power sources.

An enhanced particle swarm optimization algorithm for improving the renewable energy penetration and small signal stability in power system

In power systems, increasing the renewable energy penetration with small signal stability is one of the demanding and critical tasks in recent days. This research work aims to develop a multistage optimization technique, namely particle swarm optimization (PSO), for improving both the energy penetration and small signal stability. Here, the wind and solar power sources are considered, and its penetration is maximized by satisfying the grid requirements such as the bus voltage, line flows, and real and reactive power generation within the limit. This work includes two stages: in the first stage, PSO algorithm is implemented for maximizing the renewable energy penetration to the test systems. Then, in the second stage, the small signal stability of the systems is improved with maximum renewable energy penetration in which the best locations for connecting the wind farm are identified by using the calculation of wind farm placement index and solar generation is fixed by considering voltage and bus load absorption capability. During simulation, the proposed method is tested and validated by using IEEE 14-bus standard system, and the 220 kV Kerala (India) grid practical system with the solar and wind power. Moreover, various measures such as power generation, load and bus voltage are evaluated for two different case studies. In this evaluation, it is proved that the renewable energy sources are safely integrated with the power system with increased energy penetration and improved small signal stability.

Sistem Pengisian Baterei Menggunakan Buck Konverter

Tulisan ini membahas mengenai penggunaan buck converter untuk pengisian baterei menggunakan sumber tenaga surya. Tegangan nominal baterei yang digunakan adalah 12 Volt 65 Ah dan tegangan keluaran panel surya tanpa beban adalah 22.68 Volt. Buck converter digunakan untuk menurunkan tegangan keluaran panel surya dan untuk mengendalikan kestabilan tegangan keluaran buck konverter digunakan mikrokontroller Atmega 8. Dari hasil pengujian yang dilakukan tegangan keluaran buck converter stabil pada nilai 14,4 volt meskipun nilai tegangan masukan bervariasi. Selain dari itu, lama pengisian baterei sangat ditentukan oleh perubahan cuaca yang mempengaruhi kemampuan panel surya untuk menghasilkan energi untuk pengisisan baterei.

Portable LED lamps

The purpose of this study was to design the Portable LED Lamp to overcome the problem of the need for power sources and lighting for outdoor activities such as camping, mountain climbing or long trips. The equipment is made up of solar cells that charge the charger through a charge controller to turn on the LED light or recharge the phone battery. The method used in this research is float charging by using the main components of LM7805 voltage regulator. The charger battery used is Li-Ion (Lithium-Ion) which is cheaper, easy to maintain and does not contain harmful substances so it is quite safe when compared to Ni-Cd (Nicke-Cadmium) and Ni-MH (Nickel-Metal Hydride). The advantages of this made system is the lithium battery can be recharged its electric charge by using solar cell power source and PLN power grid.

Flexible operation of electrolyser at the garage forecourt to support grid balancing and exploitation of hydrogen as a clean fuel

Rapid growth in the generation of renewable energy (RE) and its integration with electricity grids has been driven by concerns about both the climate impacts and the depletion of fossil fuels. Moreover, these concerns have prompted the need to develop alternatives to hydrocarbon fuels, leading to the expectation that fuel cell vehicle numbers will similarly increase. However, the variable and intermittent output of RE generators significantly affects the capability for electricity networks to balance supply and demand, although this may be addressed through energy storage and demand-side response (DSR) technologies. One potential DSR technique that can be implemented at industrial scale is water electrolysis, which is used for hydrogen production. When electrolyser operation is modulated, for example, to respond to the variable output of wind and solar power sources, it can be exploited as a dispatchable demand load. Naturally, this would need to be incentivized by electricity tariff structures that reflect the dynamics of RE availability. This paper aims to compare the economics of continuous and dispatchable electrolyser operation for producing affordable hydrogen at garage forecourts in Libya, while ensuring no interruption in the fuel supply to vehicles. Using the coastal city of Derna as a case study, with renewable energy generated by a wind farm, a suitable turbine specification and the number of turbines needed to meet demand was determined through an analysis of wind speeds. The constantly varying difference between RE power supply and electricity demand on the grinded the surplus power at any given time. Using a linear programming algorithm to optimize the hydrogen cost, based on the current price of electricity, this study examines a hydrogen refuelling station in both dispatchable and continuous operation. As the capital cost is already known, the optimisation focuses on the variable cost in order to reduce the price of hydrogen, which means using the cheaper of two electricity tariffs. Three scenarios were considered to evaluate whether the cost of electrolytic hydrogen could be reduced through using lower-cost off-peak electricity supplies:1- Standard Continuous, in which the electrolyser operates continuously on a standard tariff of $16/kWh.2- Off-peak Only, in which the electrolyser operates only during off-peak periods at the lower price of $7/kWh.3- 2-Tier Continuous, in which the electrolyser operates continuously on a low tariff at off-peak times and a high tariff at other times.The results indicate that Scenario 2 produced the cheapest electricity at $3.89 per kg of hydrogen, followed by Scenario 3 at $5.10 per kg, and the most expensive was Scenario 1 at $9.26 per kg.

Implications of net energy-return-on-investment for a low-carbon energy transition

Low-carbon energy transitions aim to stay within a carbon budget that limits potential climate change to 2 °C—or well below—through a substantial growth in renewable energy sources alongside improved energy efficiency and carbon capture and storage. Current scenarios tend to overlook their low net energy returns compared to the existing fossil fuel infrastructure. Correcting from gross to net energy, we show that a low-carbon transition would probably lead to a 24–31% decline in net energy per capita by 2050, which implies a strong reversal of the recent rising trends of 0.5% per annum. Unless vast end-use efficiency savings can be achieved in the coming decades, current lifestyles might be impaired. To maintain the present net energy returns, solar and wind renewable power sources should grow two to three times faster than in other proposals. We suggest a new indicator, ‘energy return on carbon’, to assist in maximizing the net energy from the remaining carbon budget. Energy systems are transitioning from fossil fuel sources to renewable sources with lower net energy generation. Using the concept of energy return on investment, this study finds that net energy per capita is likely to greatly decrease without more efficiency savings or energy infrastructure.

Analyzing Integrated Renewable Energy and Smart-Grid Systems to Improve Voltage Quality and Harmonic Distortion Losses at Electric-Vehicle Charging Stations

Increasing the use of electric vehicles (EVs) is regarded as a step in the right direction to reduce air pollution and carbon emissions. However, a dramatic increase of EV and charging stations has raised voltage quality and harmonic distortion issues that affect the performance of integrated renewable power sources (wind and solar) and smart-grid electrical transmission networks. This paper models an integrated electric vehicle charging and battery storage system operating in the presence of unpredictable wind and solar power sources. The aim is to enable the design of an electrical control system that develops the correct duty cycle to stabilize and regulate the voltage at the dc/dc power conversion station. Simulations are performed to evaluate energy management by the proposed control system. The proposed system effectively manages the electric power on the grid by drawing power from the batteries at peak times and then charging them in off-peak times, reducing the load on the converter and enabling the reduction of charging time for electric vehicles. A constant voltage is achieved on the grid irrespective of fluctuations in renewable energy generation and in the load.

Critical Review—Experimental Diagnostics and Material Characterization Techniques Used on Redox Flow Batteries

Grid-scale energy storage systems are of interest as the world increases reliance on renewable energy sources. Redox flow batteries are a type of grid-scale energy storage technology that shows exceptional promise for accommodating the dynamic output of wind and solar power sources. The research community employs dozens of diagnostic techniques to investigate nearly all facets of these devices. Material properties, operational losses, transport, and integrated system properties are studied through the lens of electrochemical, physical, and chemical phenomena that ultimately dictate cost by influencing efficiency, durability, power, and capacity. These diagnostic techniques can, if applied correctly, elucidate not only the types of losses in redox flow batteries, but also tie those losses to fundamental driving forces in such systems so that next generation systems and models can be designed. This review details various diagnostic techniques used in flow battery analysis. The benefits, unique insights, and limitations of these techniques are discussed. Recommendations are also made to assist researchers in identifying the diagnostics that can advance their particular investigations. The review concludes with a summary of opportunities for new diagnostics that are needed to enable solution of persistent issues in redox flow battery research and development.

Design, construction, testing and performance of split power solar source using mirror photovoltaic glass for electric vehicles

Solar photovoltaic panels are prominently integrated into electric vehicle rooftop to charge the battery bank. In this paper, the performance of the conventional solar power source architecture employed in electric vehicles is analyzed using PVsyst real-time simulator. The limitations with solar photovoltaic panels and conventional solar power source are addressed through a novel mirror photovoltaic glass and split power solar source architecture. The design, manufacturing and structural merits of split power solar source are presented. The operational behavior of split power solar source is validated using Matlab. The performance of the mirror photovoltaic glass is analyzed at standard test conditions and various combinations of irradiation and temperatures using climate chamber solar simulator. The performance of mirror photovoltaic glass at on-site conditions is analyzed by comparing with climate chamber solar simulator results. Further, the analysis is validated through a convection analysis carried out using ANSYS. Subsequently, the performance of the split power solar source is studied using PVsyst real-time simulator. The split power source architecture is obtained as the best feasible solar power source design for an electric vehicle in terms of material requirement, replacement cost, withstanding capability, space utilization, power loss, tracking mechanism feasibility and performance through the comparative study.

Design and simulation of front end power converter for a microgrid with fuel cells and solar power sources

The need for Renewable Energy Sources (RES) is increasing due to increased demand for the supply of power and it is also environment friendly.In the recent few years, the cost of generation of the power from the RES has been decreased. This paper aims to design the front end power converter which is required for integrating the fuel cells and solar power sources to the micro grid. The simulation of the designed front end converter is carried out in the PSIM 9.1.1 software. The results show that the designed front end power converter is sufficient for integrating the micro grid with fuel cells and solar power sources.

Performance analysis of a solar-only gas micro turbine, with mass flow control

Micro gas turbine applications in concentrating solar field systems is already on industrial stage. The peculiarity of these systems is the possibility to use fossil fuels when solar power source is lacking. It is preferable that the system works in solar-only mode for long time; however, owing to the efficiency loss which occur for low radiation levels, a fuel integration is necessary.This work presents a system which allows to operate with constant efficiency, without the use of fuel for over one fifth of the nominal power rate. It is based on a regenerated micro gas turbine in closed loop configuration. The proposed system includes the solar tower, the heliostats field, the regenerator and a low temperature heat exchanger which cools the working fluid. Finally, two more devices, for the actuation of the proposed control are included: an auxiliary compressor and a bleed valve.The use of air as working fluid has been analyzed, with different values of the base cycle pressure (inlet pressure of the main compressor), which are needed for varying the mass flow flowing in the system. The control of the mass flow rate is mandatory to regulate the gas turbine power, by keeping almost constant the maximum temperature of the thermodynamic cycle when the incident solar radiation changes. In particular, the auxiliary compressor admits fresh air in the cycle when the thermal power received by the sun increases, while the bleed valve discharges it in the atmosphere, when the thermal power decreases. Therefore, the thermodynamic cycle is unchanged and guarantees constant net system efficiency for all the operations conditions.Particular attention is given to the receiver thermal incident flux, heliostat field and solar tower design. The current results are compared with the annual efficiency and energy production of an existing plant in hybrid configuration (solar-fuel).The analysis has been carried out on a commercial gas turbine having a power of 100 kW, sited on Seville town. For the heliostat field analysis, the open source code Solar PILOT has been used, while for the entire plant the code Thermoflex has been employed.

A Transportable Solar Power Generator

Abstract—This paper presents the design of a 2kW portable photovoltaic (PV) stand-alone facility (PV generator) that converts directly solar irradiance into electricity for immediate use or storage. The project aims to build a stand-alone solar power source for use in rural villages, mountainous and remote areas that are distant from the national grid. It can also be very useful for powering camping tents, fishing boats, small farms, and greenhouses. Equally, it could be used for disaster stricken areas and during power outages. However, the proposed generator will be more suited for camping trips that Emiratis take almost in weekly basis. The paper will focus on presenting the main features of the designed prototype. It will also investigate the performance of the proposed stand-alone PV generator. Parameters investigated include geographic location, climate condition, solar irradiance, load consumption, ambient temperature, array voltage, battery voltage, and energy output from the array. The work presented is based entirely on the work carried out by final year electrical engineering students, during their capstone design project. The project work, presented, is a manifestation of the students learning during earlier semesters. It puts into practice the application of solar energy technology, that the student learned in his course on renewable energy systems.
 Index Terms—Solar energy,transportable solar system,stand-alone system,PV,photovoltaic system.