Abstract

In recent years, floating photovoltaic (FPV) systems have emerged as a promising technology for generating renewable energy using the surface of water bodies such as reservoirs, lakes, and oceans. FPV systems offer several advantages over traditional land-based solar arrays, including increased land-use efficiency, reduced water evaporation, and improved cooling and maintenance. However, like all solar power systems, FPVs are subject to variability and intermittency due to changes in weather, seasons, and time of day. The environmental impact is discussed along with the deployment consideration and the feasibility for a better understanding of the system. Challenges associated with this are addressed by progressed research suggesting the integration of FPVs with various energy storage and hybrid systems. The most promising areas researched in this paper look at hybrid FPV hydropower plants (HPP), in parts of the world experiencing droughts HPP is not working to its optimum capacity. A review of available literature has been conducted on the topic of offshore and onshore floating solar electricity generation using floating solar photovoltaics to identify the challenges and opportunities presented. This work looks at a variety of other hybrid FPV energy sources with varying technology readiness levels. This paper concludes with the possibility of integrating different renewable technologies with existing FPVs and highlights the boons of doing so with some examples. Ultimately, current as well as future perspectives have been provided which consolidate the current research being done and give recommendations for future research work.

Introduction

One of the biggest challenges that is faced by the world is global warming due to which both humans and the planet are suffering as a whole, this is directly linked to the burning of the fossil fuels that we rely on to facilitate our daily life. The Intergovernmental Panel on Climate Change (IPCC) set out the impacts of global warming 1.5 °C above preindustrial levels [1]. We are not currently on course to limit 21st-century global warming to under 1.5 °C or even 2 °C [2]. Another key issue is the lack of clean electrification for a vast population which is hampering the development of the planet in tackling the climate change issue as many rely on the burning of fossil fuel for various daily requirements from generating electricity to cooking. It has been estimated that about 675 million people are still forced to live in the dark most of them belong to sub-Saharan Africa according to 2021 data. Though there has been an increase in the rate of access to electricity from 87% in 2015 to 91% in 2019, this has provided electricity to nearly 800 million people [3]. This is where solar PV can play a substantial role, solar PV has the benefit of being a renewable energy source, producing electricity from solar irradiance without any greenhouse emission [4].

However, there are challenges that must be addressed in order to fully realize the potential of solar energy and traditional photovoltaics [5]. These challenges include land usage, intermittency, storage, and integration into existing energy grids. One promising and upcoming alternative to traditional land-based photovoltaics is Floating Photovoltaics (FPV) or flotavoltaics [6]. The majority of renewable energy sources, such as biomass, solar, and others, take considerable footprint areas to generate electricity on a larger scale, which restricts the use of land for agriculture [[7], [8], [9]]. This sparked the discussion over whether land should be used for food production or energy production [10,11], encouraging research into offshore renewable technologies [12], and led to the creation of the floating photovoltaic (PV) array concept for the production of commercial electricity [13]. FPV technology is a concept in which solar panels are placed on platforms that float on water bodies such as natural lakes, man-made reservoirs, and the seas and oceans [14]. Fig. 1 shows a typical standalone floating photovoltaic system with all the components including an inverter, pontoons, solar panels, and cables connected to the grid.

Conclusion

This review article has examined the current state of research on the integration of floating photovoltaics with different storage and hybrid systems, including batteries, pumped hydro storage, compressed air energy storage, hydrogen storage and mixed energy storage options as well as the hybrid systems of FPV wind, FPV aquaculture, and FPV hydrogen production. The findings suggest that such systems have the potential to significantly increase the efficiency and reliability of renewable energy generation, as well as provide additional flexibility in managing electricity supply and demand.

FPV has many benefits over ground-mounted such as reduced land costs, increased efficiency, reduced soiling, reduced shading, reduced evaporation, and lower visual impact. Hybrid FPV has all of these benefits while being able to reduce its lifetime costs when paired with another technology a reduction in O&M costs, grid infrastructure and cable pooling. Overall, hybrid FPV has all the benefits of FPV plus reduced costs, while enhancing another technology. While FPV is set to rise this will initially be in land first with offshore following, the priority should be covering HPP first due to its complementary nature and benefits for both technologies. Countries, which have HPP reservoirs, should be looking into all the benefits of combining FPV with it. As FPV becomes more common it will be seen moving offshore, as the offshore wind increases it creates the opportunity for FPV to become a hybrid system.

Abstract

Keywords

1. Introduction

2. Related work

3. Application research of Internet of Things in solar photovoltaic power station monitoring and management system

4. Development of integrated computer-aided design system for solar photovoltaic buildings

5. Conclusion

Declaration of Competing Interest

References

Abstract

At the same time of economic development, the increasing scarcity of energy has had a great impact on people’s development. People’s production and life demand for electricity is also increasing rapidly, and solar power technology has received more and more attention. As a new energy source, solar energy has the advantages of environmental protection and sustainability, and it has no regional restrictions, can be used on-site, and designed to scale. Solar power generation is an important way to use solar energy. As the main component of the grid-connected power generation system, solar grid-connected inverters complete the tracking problem of the maximum power point in the photovoltaic array and transmit electrical energy to the grid through a set of control algorithms. The electrical energy is transmitted to the grid through the inverter, consistent with solar energy. In order to solve the problems of low integration, low energy efficiency, low reliability, high power consumption and lack of effective monitoring measures for solar energy devices. This article starts with the design of the solar cell integrated system, and through detailed analysis of the solar production system and building integrated planning, establishes the shadow radiant energy model of the solar cell system building electrical and solar cell system based on the Internet of Things, and designs an object-based Networked comprehensive auxiliary platform.

1. Introduction

Today’s society is an information society centered on the Internet. Digitization, informationization and world economics are the hallmarks of the current era. With the continuous rapid development of information technology, the process of world economics has been continuously strengthened. The use of computer technology, communication data and the Internet to complete e-logistics and Internet commerce has been widely used in society. The continuous improvement of information technology and information storage is just the prelude to the transformation of the IT industry. The cost of information dissemination is getting less and less, and it is bound to usher in the era of the Internet of Things dominating. As a post-IP product, the Internet of Things is developing rapidly and will become popular in the future. This is a major plan to realize the intelligentization of the world.

Abstract

INTRODUCTION

COMPUTATIONAL METHODS

DPD Method

Drift-diffusion Model

RESULTS AND DISCUSSION

One-step Quench

Two-step Quench

Comparison with Existing Experimental Observations

CONCLUSIONS

REFERENCES

Abstract

     The mixing morphology control plays a crucial role in photovoltaic power generation, yet this specific effect on device performances remains elusive. Here, we employed computational approaches to delineate the photovoltaic properties of layered heterojunction polymer solar cells with tunable mixing morphologies. One-step quench and two-step quench strategies were proposed to adjust the mixing morphology by thermodynamic and kinetic effects. The computation for the one-step quench revealed that modulating interfacial widths and interfacial roughness could significantly promote the photovoltaic performance of layered heterojunction polymer solar cells. The two-step quench can provide a buffer at a lower temperature before the kinetic quenching, leading to the formation of small-length-scale islands connected to the interface and a further increase in photovoltaic performance. Our discoveries are supported by recent experimental evidence and are anticipated to guide the design of photovoltaic materials with optimal performance.

Introduction

     Polymer solar cells (PSCs) are a kind of potential clean-energy technology, which holds promise for manufacturing lightweight and highly flexible devices such as portable electronic products and building-integrated photovoltaics.[1−5] Although the power conversion efficiency was dramatically improved recently, it has not yet broken through the requirements of commercial markets due to the limitation on the mechanism of charge carrier generation and transport.[6,7] To date, a considerable effort has been devoted to creating novel π-conjugated polymers to improve photovoltaic performance. In contrast, understanding the morphology effect on PSC performance and formulating basic rules that guide morphology optimization need to be further enhanced.

     Optimizing the morphology is indispensable for the successful preparation of PSCs with outstanding performance.[8−12] The PSC performance can be quantitatively correlated with phase purity and Flory-Huggins parameters.[13] Insufficient phase separation in PSCs can lead to performance deteriorations. However, a larger repulsion between donors and acceptors can lead to over-purification of mixed domains and decreased PSC performance.[14] For example, Ade et al. observed that the average power conversion efficiency shows a substantial drop as the composition of the amorphous mixed domains is below the percolation threshold.[15] Ye et al. recently found that such a problem can be resolved by kinetically quenching the mixed domains to an optimal composition close to the percolation threshold.[16] Despite this, fundamental guidelines are still required to optimize PSC performances with optimal mixing morphologies. Combining thermodynamic effects and kinetic controls can assist the design of heterojunctions with varied mixing morphologies.[16] The thermodynamics can drive the phase separation of donors and acceptors in PSCs, and the quench by kinetic control can “lock-in” instantaneous phase-separated morphologies. Recent attention has been paid to the stability of such mixing morphologies.[17−20] However, little is known about the kinetic route to control mixing morphologies and the influence of mixing morphologies on PSC performances. Quantifying the impact of mixing morphology on device performance by developing kinetic control rules is the key to optimizing the heterojunction structure and promoting power conversion efficiency.

Conclusion

     The DPD method, coupled with the drift-diffusion model, was employed to study the mixing morphology effect on the photovoltaic performance of layered heterojunction PSCs. We performed an in silico layer inter-diffusion experiment and designed two quench approaches to regulating the mixing morphology of layered heterojunctions, that is, one-step quench and two-step quench. In the one-step quench, the layered heterojunction with intermediate interfacial width exhibits an optimal photovoltaic performance. We further enhanced the power conversion efficiency of the layered heterojunction by modulating the mixing morphology with a two-step quench method. We discovered that the interfacial width, interfacial roughness, and small-length-scale island structures formed within acceptor- and donor-rich domains combinedly affect the power conversion efficiency. Our work delineates the effect of quenching processes on photovoltaic performance, which could be beneficial to the design and quantitative optimization of active layers.

Abstract

1. Introduction

2. PV cell model and design parameters

3. Fuzzy Distribution of PV cell parameters

4. Global sensitivity analysis of PV cell parameters

5. Analysis and discussion

6. Conclusion

CRediT authorship contribution statement

Declaration of competing interest

Acknowledgments

References

Abstract

     Photovoltaic cells can directly convert solar energy into electrical energy, which is environmentally friendly and has a wide range of applications. In practical engineering, the uncertainty of photovoltaic cell parameters has an important impact on cell performance. In order to study the influence of parameter uncertainty on the output performance of photovoltaic cells, a photovoltaic cell model is established and five parameters are selected: irradiation intensity, photovoltaic cell surface temperature, temperature coefficient, equivalent series resistance and equivalent parallel resistance. The influence of these parameters on the output power and conversion efficiency of photovoltaic cells is studied by using the global sensitivity analysis method based on fuzzy theory. The principal and total global sensitivity indexes describing the influence of each parameter on the output performance were therefore calculated and ranked. The key parameters influencing the performance of photovoltaic cells were determined to be related to cell surface temperature and equivalent parallel resistance. In actual production and life, the output performance of photovoltaic cells can be improved by controlling these two factors. The results of this study can help to guide the performance analysis and parameter optimization of photovoltaic cells, accelerating the development and improving the adoption of photovoltaic systems.

Introduction

     With the aggravation of the global energy crisis and increasing environmental pollution, the development of solar energy occupies a critical position in the energy structure (Wang et al., 2021b, Xiong et al., 2022). As photovoltaic (PV) cells directly convert solar energy into electric energy, they represent an increasingly popular source of renewable energy. The number of deployed PV power generation systems has significantly increased worldwide (Wang et al., 2021a, Wu et al., 2022), and many countries have introduced grid pricing policies to accelerate investment in PV power generation. Therefore, research into the performance of PV cells is of great significance for ensuring their continued adoption (Sharma et al., 2021, Sadan and Dwivedi, 2020). To date, many experts and scholars have studied the parameters of PV cells (Chehreh Ghadikolaei, 2021, Chen et al., 2020, Chandran et al., 2021, Ganesh Pardhu and Kota, 2021, Ji et al., 2021). For example, Chen et al. (2020) used variables reduction and improved shark optimization technique to extract photovoltaic cells parameters, Chandran et al. (2021) proposed an improved distribution estimation algorithm to estimate the optimal parameters of fuel cells and solar cells, and Ganesh Pardhu and Kota (2021) proposed a new random radial shift optimization algorithm based on a group algorithm to extract the unknown parameters of solar PV cells. The confirmation and extraction of parameters of photovoltaic cells and their components is of great significance for evaluating the performance of photovoltaic cell systems and preventing aging and failure of systems and components.

Conclusion

     To address the instability of PV cell output performance according to the inherent fluctuation of design parameters, this study applied the global sensitivity index based on fuzzy theory to measure the influence of inherent design parameter fluctuation on the stability of PV cell output power  and conversion efficiency . The Monte Carlo method was used to calculate the principal and global sensitivity indexes of the design variables based on the credibility variance. The results show that compared with the cell surface temperature  and equivalent parallel resistance , the total global sensitivity index values of the short-circuit current temperature coefficient , irradiation intensity , and equivalent series resistance  are minimal for both the output power  and conversion efficiency , and the effects of their variation can therefore be ignored. Therefore, the key design parameters of PV cells are related to the working environment () and material (). In actual production and application, the output performance of PV cells can therefore be improved by controlling material selection(ensure a consistent equivalent parallel resistance ) and expected working environment temperature . The results of this study can provide guidance for the design and optimization of future PV cells, and further improve their application and utility to increase adoption.

Abstract

Introduction

Methodology

Data collecti

Performance of ANN forecaster

Performance of hybrid-ANN forecaster

Performance of hybrid-ANN forecaster-S

Conclusion

Nomenclature

Acknowledgments

Disclosure statement

References

Abstract

     The integration of solar photovoltaic (SPV) system to the grid has introduced a new source of intermittency in the grid, and the grid has to react smartly to the changes that occur in the penetration of SPV power. Accurate modeling of weather-dependent SPV power will be helpful in forecasting the penetration of SPV power into the grid. An SPV power output forecasting model has been developed based on artificial neural network (ANN) approach. Two forecasters, namely ANN forecaster and two-stage hybrid-ANN forecaster, are developed with operational and weather parameters. The historical data of SPV power (P), hours of operation of SPV system (to), daily global solar radiation (H), and ambient temperature(T) are used as modeling parameters. The combination of modeling parameters {P, H, T, to} is identified as the best combination that influences the forecasting of day-ahead power output. A relative root mean square error (RRMSE) of 5.74% was obtained with the combination of {P, H, T, to}. An RRMSE of 6.04% was observed with the combination of {P, H, T} as inputs, and the hours of operation of the SPV plant could be ignored in the model. The historical power data of the SPV plant is identified as the crucial parameter in the SPV power forecast model and has given an RRMSE of 7.25%.

Introduction

In recent times, the consumption of energy from conventional sources has been increased, which causes the rapid depletion of fossil fuel-based resources. The emission of greenhouse gases has increased because of the utilization of conventional sources over the past few decades (Fikru and Gautier 2015). In addition to that, the energy demand has been increasing enormously in both developed and developing countries due to the increase in population, urbanization, and industrialization. The portion of this energy demand can be met by renewable energy sources (RES) such as wind and sun. Solar energy can be captured by installing solar collectors, solar ponds, solar chimneys, and solar photovoltaics (SPVs). Out of all these installations, the SPV installation growth rate has increased enormously. The generation of electricity using SPV is widely accepted (Larson, Nonnenmacher, and Coimbra 2016). PV power generation is ecofriendly because it produces no toxic emission, of low maintenance, of noiseless operation, and it is abundantly available (Yan et al. 2021). Up to now, several thousands of SPV systems of 1 kW to several hundreds of megawatts have been installed and integrated into the grid worldwide (Tina, Scavo, and Gagliano 2020). The integration of SPV systems to the grid has introduced a new resource of intermittency in the grid (Sepasi et al. 2017). This is due to the sensitivity of the SPV system to local weather conditions and variation in solar radiation availability. The SPV power output is uncertain since the parameters like irradiance level, ambient temperature, surface temperature of the panel, dust deposits, wind speed, cloud cover, and relative humidity etc., will have an impact on the SPV power generation. Accurate modeling of SPV power is required by the utilities to control the high instabilities of the electric grid due to unpredictable PV power penetrations (Wan et al. 2015).

Conclusion
A day ahead SPV power forecast models are developed by using ANN approach. Daily GSR (Hm, Hp), ambient temperature, hours of operation of SPV system, and historical data of SPV power are used as input parameters in the modeling of the day ahead forecast models. The trial and error method has revealed that the ANN model with three neurons in the hidden layer with linear-log-sigmoid transfer function has shown the best performance.

     The effect of each parameter and the combination of parameters on the model accuracy is identified by developing various forecast models, and a total of 21 forecast models are developed. Out of the 21 developed forecast models, ANN forecaster-4 with the combination of inputs {P, H, T, to} has shown the best performance. The combination has shown a strong influence on the SPV power output. The MAPE of 4.18% and the RRMSE of 5.74% are derived with 4-3-1 ANN architecture. Historical data of measured power is the best suitable modeling parameter to predict the SPV power. Historical power measurements will not be available before the installation of the SPV system, and in such cases, ANN forecaster-2 with {Hm, T} could be used as a forecast model.

Abstract

     Energy efficiency is one of the most important issues of today. The limited reserves of fossil fuels make the use of renewable energy sources more attractive. Photovoltaic panels are one of the ways to utilize solar energy, which is one of the renewable energy sources.

     The instantaneous efficiency of photovoltaic panels is related to the cell temperature of the panels. In the current studies in the literature, there are empirical expressions that give the photovoltaic panel cell temperature, but the results obtained from these expressions do not overlap with each other. In order to obtain the instantaneous efficiencies of photovoltaic panels and, accordingly, the production values theoretically, there is a need for a global expression that gives the photovoltaic panel cell temperature. In this study, a global expression was developed that gives the photovoltaic panel cell temperature depending on the ambient temperature, solar radiation and wind speed. In addition, using the meteorological data of Kütahya for many years, expressions giving ambient temperature, solar radiation and wind speed were created.

Introduction

     The limited reserves of fossil fuels make renewable energy sources more attractive day by day. While the world primary energy consumption was 581.51 exajoules in 2019, this value was 557.1 exajoules in 2020 (BP, 2021). The amount of renewable energy sources in primary energy consumption in 2019 was 28.82 exajoules (5 %), and in 2020, primary energy consumption from renewable energy sources was 31.71 exajoules (5.7 %) (BP, 2021). From renewable energy sources, 2,789.2 TWh of electricity was produced in 2019 and 3,147.0 TWh in 2020 in the world. While total solar energy production was 707.9 TWh (25.4 %) in 2019, total solar energy production was 855.7 TWh (27.2 %) in 2020 (BP, 2021).

     Table 1 and Table 2 show the solar energy installed power and solar energy production values for 10 years between 2011 and 2020 (BP, 2021). When the tables are examined; It is seen that the installed PV power in the world has increased by 882 % in 10 years. Likewise, electrical energy production from PV systems has increased by 1,212 % over the 10-year period.

     Fig. 1 shows Turkey’s solar energy situation. While the total installed power was 7 MW as of the end of 2011, this value increased by 95,143 % and reached 6,667 MW at the end of 2020. Likewise, while electricity generation from solar energy was 2.86 GWh in 2011, this value increased by 378,732 % in 10 years and reached 10,834.6 GWh (BP, 2021).

Evaluations and suggestions

     In the current studies in the literature, there are empirical expressions that give the photovoltaic panel cell temperature, but the results obtained from these expressions do not overlap with each other. In order to obtain the instantaneous efficiencies of photovoltaic panels and, accordingly, the production values theoretically, there is a need for a global expression that gives the photovoltaic panel cell temperature.

     The instantaneous efficiency of the photovoltaic panel and the generation of electrical energy depending on the efficiency are related to the cell temperature of the photovoltaic panel. Within the scope of this study, a global expression that gives the photovoltaic panel cell temperature was created by using real photovoltaic plant data with the 7 most popular expressions in the literature that give the photovoltaic panel cell temperature. With the obtained expression, instantaneous photovoltaic panel temperature can be obtained depending on the ambient temperature, solar radiation and wind speed.

The conventional bypass diodes used in solar photo-voltaic panel have side-effects of forward voltage drop, reduction in efficiency and a few operational problems under partial shading condition. In this work, this bypass diode is replaced by an electromagnetic relay through an efficient alternative approach that consumes less power and offers higher efficiency under partial shading condition of solar module. This approach removes the problems like hotspot formation of the solar cell, open circuit fault under shading condition. A part of this work has been reported and published as an Indian patent. In this extended research work, the different components are designed for the partial shading condition. The hardware setup is developed, and hardware results are compared and validated with the simulated results. The proposed electromagnetic method, with no semiconductor device, works efficiently and effectively under partial shading (low irradiance) scenarios.

1. Introduction

In the present era of renewable energy sources, the solar energy has emerged as one of the most eco-friendly source of usable energy. It is extensively used across the globe since solar cells generate different outputs depending on various environmental factors. The solar modules’ performance is reduced to an appreciable extent by the shading effects and hence an urgent need arises for more efficient and reliable solution. Low irradiance and shading conditions are manageable by facilitating the load current through an alternate path and this can be done by using bypass diode. The resistance of the cell under shadow becomes high and this is why the bypass diode requires. The load current determines the amount of power dissipated by the bypass diode. The efficiency of the solar panel is significantly reduced by the bypass diode. That is why it is essential to sensibly arrange the number of bypass diodes in a PV (Photo-Voltaic) module. It is highly significant to reduce the losses in the PV panel having bypass diode.

Introduction

Experimental Procedures

References

SUMMARY

The significant capital expense of photovoltaics manufacturing has made it difficult for new cell and module technologies to enter the market. We present two technoeconomic models that analyze the sustainable growth of perovskite manufacturing for an R2R single-junction technology and a perovskite-silicon tandem module, focusing on the impacts of economies of scale and average selling price on profitability. We establish a cost range of $3.30/W to $0.53/W for flexible modules manufactured in factory sizes ranging from 0.3 MW/year to 1 GW/year. In addition, we model the cost to manufacture a tandem module consisting of a single-junction perovskite cell stacked in 4-terminal configuration onto a silicon cell and show how an existing manufacturer can grow at a faster rate by co-investing in tandems. Our analyses highlight potential routes to market for perovskite photovoltaics and the possibility to sustainably grow a photovoltaics manufacturing company even in markets with higher labor rates.

INTRODUCTION

To mitigate the impacts of climate change, tens of terawatts of solar power must be deployed over the next decades. With 500 GW of photovoltaics (PVs) installed globally to date, silicon photovoltaics remains the incumbent technology with its cost now at 0.25 $/W and declining capex. The rapid growth of installed photovoltaics continues to surprise even the experts, but for solar power to become the primary source of electricity globally, a large-scale and truly global manufacturing base is required that will not be able to rely on one region or technology. In light of this, perovskite photovoltaics offer a strong alternative photovoltaic technology with the potential for extremely low manufacturing costs through solution processing that could compete with silicon. However, new cleantech technologies have historically struggled to scale-up with their capital intensity resulting in long timelines for commercialization that are incompatible with traditional venture capital funding models, that lead to lower success rates for cleantech startups compared to software and medical ventures. In this paper, we use bottom-up cost modeling to explore economically sustainable strategies for one new cleantech innovation, solution-processed perovskite photovoltaics, to scale-up and enter the mature solar power market. Our goal is to help illuminate one or more pathways that could enable this groundbreaking technology to successfully scale-up and navigate the journey from lab bench to market.

1- Introduction

2- System design

3- Case study and simulation data inputs

4- Simulation results

5- Discussion

6- Conclusion

References

Abstract

Cloud transients cause rapid fluctuations in the output of photovoltaic (PV) systems, which can significantly affect the voltage levels in a low-voltage (LV) grid with high penetration of PV systems. These voltage fluctuations may lead to violation of the existing power quality standards. This study estimates the impact of rapid PV output fluctuations on the power quality in an existing LV grid by performing load flow analyses for scenarios in the years 2017, 2030 and 2050 using PV data with 20-second resolution. In this study, we propose a system for the mitigation of PV output fluctuations by altering the charging processes of electric vehicles (EVs) and we assess the effectiveness of the proposed system. Results indicate that PV output fluctuations have minor impact on the voltage levels in the year 2030, but PV output fluctuations induce considerable voltage fluctuations in the year 2050. The magnitude of the voltage fluctuations is dependent on the location in the grid, the installed PV capacity and the grid configuration. These voltage fluctuations can induce visible and annoying light flicker for a significant part of the day in the year 2050. Implementing the proposed system shows that EV technology can contribute in reducing the amount of visible and annoying light flicker considerably, however at the expense of increased charging costs for EV owners.

Introduction

The ongoing surge in photovoltaic (PV) generation capacity in low voltage (LV) grids poses unprecedented challenges to distribution system operators (DSOs). Passing clouds induce short-term variability in the output of PV systems. Fluctuations of 45–90% of the rated PV capacity per minute induced by passing clouds have been reported for a large PV plant in Portugal [1] and fluctuations of 63% of the rated PV capacity per minute have been measured in a Hawaiian PV plant [2]. Cloud transients also result in considerable PV output fluctuations on a shorter time-scale; PV output fluctuations of 80% of the installed PV capacity per 2 seconds have been observed in Spain [3]. The intermittent nature of PV generation is the source of power quality issues. The main power quality problems associated with rapid PV output fluctuations are voltage fluctuations and light flicker, which is induced by voltage fluctuations [4]. Voltage fluctuations and flicker can cause damage to electrical appliances connected to the grid [5] and light flicker can cause annoyance and health problems to people exposed to it [6,7]. For this reason, European DSOs must comply to the EN-50160 power quality standards [8]. The relationship between PV power output fluctuations and light flicker has been addressed in multiple studies, with inconclusive results. A Malaysian case study demonstrated a positive relationship between the installed PV capacity and flicker values, and reported flicker values induced by PV power output fluctuations that violate the local flicker limits [9]. In addition, a study using a measurement setup for 69 PV modules concluded that fluctuations in PV generation can lead to considerable light flicker values, depending on the metric used to measure flicker values [10]. However, an empirical analysis of a 1.41 MW PV plant in Florida reported a low correlation between PV power output and measured flicker values [11], but this study did not look into the correlation between fluctuations in PV generation and flicker values. Similarly, Stewart et al. [12] concluded based on Hawaiian solar irradiance data that PV generation does not cause violation of the light flicker standards. The flicker values in this study were determined by using the flicker threshold values for 1-second and 2-second voltage fluctuations and by using 1-second and 2-second PV generation data, but this study did not consider the fact that PV output fluctuations on a longer timescale can also induce light flicker [6].

1- Introduction

2- The status of DPV in China

3- Obstacles and issues of distributed photovoltaic development

4- Analysis of China’s distributed photovoltaic grid-connected electricity price route

5- Conclusions

References

Abstract

The distributed photovoltaic power generation is an important way to make use of solar energy in cities. China issues a series of policies to support the development of distributed photovoltaics in law, electricity price, grid connection standard, project management, financial support and so on. However, there are still some defects in policies and market mechanism. China creates a competitive market with a significant number of projects of distributed photovoltaic power through the reform of the electricity market, yet substantial drawbacks of the corresponding investment subsidies prevent distributed photovoltaic power from rapidly developing. This paper summarizes the status quo of China’s distributed photovoltaic power development, given its long-term plan, presents excellences and shortcomings of the existing policy system, and looks into the supporting policies and implementation paths for China’s distributed photovoltaic power in different stages. Innovative business models and financial support models are conducive to the development of distributed photovoltaic power. Financial innovation methods such as crowd funding and asset securitization should be encouraged to develop a sound risk assessment mechanism for projects, involve insurance institutions, and establish a risk sharing mechanism. In the context of a series of supporting policies, the distributed photovoltaic power in China will move towards market-oriented standardization for a healthier and more stable development.

Introduction

As Chinese government promote clean energy development, the photovoltaic power (PV) involving centralized photovoltaic power (CPV) and distributed photovoltaic power (DPV) has been developing rapidly (Wenjing and Cheng, 2016). Due to the high land cost of the CPV (Ming, 2017), its development has been limited. However, DPV, which has a higher rate of return on investment (Hanqiao et al., 2014) and lower risk (Quansheng et al., 2016; Kirova and Velikova, 2016), is becoming the future development direction of PV. China has carried out ‘‘golden sun demonstration project’’ (Junhao, 2013) and ‘‘building-integrated photovoltaic’’ (Zhi, 2009) to promote the development of DPV. Before 2007, the PV industry was in the initial stage of pilot. From 2009 to 2012, China implemented five phases of the ‘‘Golden Sun project’’ and ‘‘photovoltaic building’’ (Changgui and (Changgui and Dacheng, 2014; Xiaoxia, 2011). The policy orientation is clear, and the DPV is growing at a rapid speed. In 2011, it was first proposed to subsidize PV with electricity price (Changsong, 2014). Since 2014, China local governments have promoted DPV in subsidies provision for electricity, equipment and so on Changsong (2013). In the early stage, the PV plants were mostly located in the west of China. However, the construction of the Western transmission channel lagged (Qiang and Ningbo, 2016), which caused the phenomenon of PV curtailment. In order to alleviate PV curtailment and promote DPV (Kunpeng, 2017; Xuehua, 2016), PV gradually developed in the middle east region of China (Xin, 2017). Therefore, the policy is an important driving force of DPV (Fengmei and Li, 2017; Jiyang et al., 2014), the research of policy is beneficial to the DPV industry (Bi, 2017). Many countries in the world have promulgated the policy of supporting DPV. In USA, the policy includes green certificate, asset assessment for clean energy loan and grid metering mechanism (Haag et al., 2012). Its preferential policy has slowed down compared with CPV though (Stokes and Breetz, 2018). The EU promotes the marketization of PV by reducing subsidies.

Modeling and simulation of photovoltaics help to reduce development costs, design turnaround time and facilitates better techno-economic decisions. However, there is a current need to generate new theories, algorithms, applications and software in order to increase the contribution of solar energy to the global energy supply. For future advancements in the field of photovoltaics, robust techniques for PV modeling, simulation, visualisation and design are required to overcome the limitations of the current approaches. This study proposes the Code-Based Modeling (CBM) approach as a potent approach to facilitate the study of PV technologies. Experimental data were synthesised and used for coding and training of the code-based (CB) model; followed by a validation of the trained model using commercial PV modules. Results clearly show that the model can repeatedly and reliably predict the short circuit current, maximum power point, open circuit voltage with 0%, < 2% and < 10% deviations, respectively. Furthermore, instances of the applicability of the CBM approach in the study of the thermodynamics of PV, solar cell materials characterisation, PV systems design and power monitoring were presented. Above all, CBM approach accepts user-defined functions and therefore presents new opportunities for scientists and engineers to advance model-based investigations of the photovoltaics beyond the current state-of-the-art.

Introduction

Research is actively being carried out on how photovoltaics can be applied as a clean source of energy because it does not emit greenhouse gases during operation (Bukar and Tan, 2019; Ogbonnaya et al., 2019a). The Renewables 2019 Global Status Report (GSR) (REN21, 2018) indicates that solar photovoltaic (PV) constitutes around 100 GW out of 2378 GW global renewable power capacity installed in 2018; which represents 55% of the renewable capacity additions in the year, followed by wind power (28%) and hydropower (11%). Apart from direct power generation with PV systems, PV could also become a primary power subsystem in integrated systems in the future. For instance, PV modules have been studied for integration with electrolysers, fuel cells and batteries for reliable power generation (Lehman and Chamberlin, 1991; Meurer et al., 1999; Özgirgin et al., 2015). Also, PV modules have been integrated with thermal absorbers to create photovoltaic-thermal (PV/T) systems to supply electricity and hot water (Avezov et al., 2011; Michael et al., 2015). The present trends in integrating PV as a power source; or as a subsystem of a hybrid system, suggest that the demand for software including PV models would increase in the future. As an example, the possibility of integrating a maximum power point tracking (MPPT) algorithm with an automotivebased software to optimise solar energy harvesting was designed and verified by (Cheddadi et al., 2018).

This paper demonstrates the optimum design and techno-economic assessment of hybrid renewable energy system (HRES) for rural electrification in the remote district of Korkadu, India. The renewable energy resources namely solar photovoltaic, wind turbine and bio generators are considered as the main sources because of its high potential in Korkadu district. This paper estimates the load forecasting for the selected district, which is a mixture of different load patterns namely residential, commercial, institutional and agricultural demands. The desired HRES has to meet the forecasted load demand for reliable electrification. The optimum design and techno-economic analysis of proposed HRES system is carried using powerful tool HOMER. This study also compares HRES’s operational behavior with different operational strategies such as load following strategy, cycle charging strategy and combined strategy of the system. The outcome of the proposed dispatched strategy expressed the contribution of solar power as 86.8%, wind as 12.7% and bio gen power as 0.5% to meet out developed rural load pattern with 6.8% of battery bank losses and 1.78% of converter losses. This research work also illustrate the HRES based power generation can be a cost effective sustainable power alternative to the conventional grid extension system.

Introduction

Total power generation capacity of India was 340 GW as on March 2018, a major portion of which 65% was from fossil fuels such as coal, oil etc. whole the renewable energy, natural gases based energy generation contributed to 19.2% [1]. The research says that still 240 millions of India are living in dark without electricity and most of the electrified villages have poor quality of electricity especially during the peak demand period i.e., during summer [1,2]. Government of India has initiated several schemes, namely, Remote Village Electrification Program (RVEP), Rajiv Gandhi Grameen Vidyutikaran Yojana (RGGVY), Jawaharlal Nehru National Solar mission (JNNSM) etc., for addressing this issue and for ensuring electrification of the rural areas in India [1,3]. The main objective of these schemes is to ensure clean source of electricity generation for the electrification of un-electrified villages in India. Various researchers have proposed an attractive solution called the Renewable Energy based Hybrid Rural Electrification System (REHRES). But the main challenges in this proposed solution relate to system reliability, power management and economical cost of energy. In addition, wide variations are seen in the renewable energy availability and its potential depending on their geographical location. Hence the optimum sizing is considered as an important parameter for the development of an efficient and economical REHRES. In recent years, various researchers have proposed the solution for REHRES worldwide such as Hydrogen fuel system based hybrid energy system has been deployed in Newfoundland [4], Solar/wind/hydrogen based HRE [5], solar/wind powered reversed osmosis system [6], PV/ wind/battery based isolated island system [7] these study clearly expressed the issues related with HRE system sizing and necessity of performance optimization of the system.

1- INTRODUCTION

2- SYSTEM LAYOUT

3- CONTROL SCHEME

4- CONCLUSION

REFERENCES

Abstract

In this paper, we are proposing currentcontrolled hill-climbing strategy used in Maximum power point tracking (MPPT) of the solar photovoltaic array to Charge OFF Board Electric vehicle lithium-ion batteries within the safety limits and supported rating of batteries so that EV battery does not get damaged and can also increase the life of the battery. Here, a current sensor and potential difference sensor-based electric vehicle off-board battery charging by hill-climbing strategy is tested on MATLAB simulation. The satisfactory steady-state battery is charging within the rated charging limit, under variable solar irradiance.

INTRODUCTION

The transportation sector has seen a major shift towards electric vehicles as it not only stops our dependence on fossil fuels and stop pollution from these vehicles that vehicles release. Hence, we are moving towards cleaner sources of energy. Also, photovoltaic resources are increasing in demand as they are the source of clean energy and don’t emit carbon dioxide

Two types of charging method are there ON Board charging and OFF Board charging. ON Board charging is when Battery is kept in the Electric vehicle and charging circuit is not on the vehicle itself but near the charging station. And the battery is charged directly through the DC supply.