Solar PV nowcasting based on skycamera observations

Abstract. In recent years the installation of PV systems has increased dramatically in many countries. Annual global installed power has already reached more than 400 GW in 2017. A major challenge for operators is that PV system output is highly fluctuating due to cloud movements and other atmospheric influences. Forecasting of solar irradiation and PV power on different time scales will, therefore, become more and more important for different users. As part of the Austrian PV-go-Smart project, several skycameras have been installed in the region of Upper Austria. In this paper we show differences and advantages of two skycams and their image qualities. Algorithms for the detection of clouds, cloud movement, and GHI forecasting have been developed and validated with ground observation at the Wels site. This work focusses on image quality issues related to short-term irradiance forecasting using all-sky cameras, in particular the influence on raindrops on forecast performance.

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Fýsileiki virkjunar sólarorku á norðurslóðum: Reynsla af sólarpanelum IKEA á Íslandi

10.33112/ije.25.1 ◽

2019 ◽

Vol 25 ◽

pp. 1-19

Author(s):

Sindri Þrastarson ◽

Björn Marteinsson ◽

Hrund Ólöf Andradóttir

Keyword(s):

Energy Production ◽

Production Capacity ◽

Production Costs ◽

Performance Ratio ◽

Solar Irradiation ◽

Specific Yield ◽

Solar Pv ◽

Solar Panels ◽

Pv System ◽

Pv Systems

The efficiency and production costs of solar panels have improved dramatically in the past decades. The Nordic countries have taken steps in instigating photovoltaic (PV) systems into energy production despite limited incoming solar radiation in winter. IKEA installed the first major PV system in Iceland with 65 solar panels with 17.55 kW of production capacity in the summer of 2018. The purpose of this research was to assess the feasibility of PV systems in Reykjavík based on solar irradiation measurements, energy production of a PV array located at IKEA and theory. Results suggests that net irradiation in Reykjavík (64°N, 21° V) was on average about 780 kWh/m2 per year (based on years 2008-2018), highest 140 kWh/m2 in July and lowest 1,8 kWh/m2 in December. Maximum annual solar power is generated by solar panels installed at a 40° fixed angle. PV panels at a lower angle produce more energy during summer. Conversely, higher angles maximize production in the winter. The PV system produced over 12 MWh over a one-year period and annual specific yield was 712 kWh/kW and performance ratio 69% which is about 10% lower than in similar studies in cold climates. That difference can be explained by snow cover, shadow falling on the panels and panels not being fixed at optimal slope. Payback time for the IKEA PV system was calculated 24 years which considers low electricity prices in Reykjavik and unforeseen high installation costs. Solar energy could be a feasible option in the future if production- and installation costs were to decrease and if the solar PV output could be sold to the electric grid in Iceland.

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Lookup Tables for Power Generation Performance of Photovoltaic Systems Covering 40 Geographic Locations (Wilayats) in the Sultanate of Oman, with and without Solar Tracking, and General Perspectives about Solar Irradiation

Sustainability ◽

10.3390/su132313209 ◽

2021 ◽

Vol 13 (23) ◽

pp. 13209

Author(s):

Osama A. Marzouk

Keyword(s):

Electricity Generation ◽

Geographical Information ◽

Solar Irradiation ◽

Research Centre ◽

Solar Pv ◽

Sultanate Of Oman ◽

Pv System ◽

Pv Systems ◽

Lookup Tables ◽

The Impact

An energy modeler for solar photovoltaic (PV) systems may be limited to climatic data of certain major cities, not covering the one for which the PV system is intended. Additionally, a person not skilled in solar PV modeling may still desire a quick estimate of PV system electricity generation to help decide the level of investment in PV systems. This work addresses these points by establishing lookup tables to summarize predicted electricity generation, solar irradiation, and optimum orientation at various locations in the Sultanate of Oman. The results are produced by processing simulation data using the online open-access tool PVGIS (Photovoltaic Geographical Information System) of the European Commission’s Joint Research Centre (EC-JRC). The tables cover 40 out of the country’s 61 s-level administrative divisions (wilayats) and cover fixed and movable PV panels. The results show that the yearly electricity generation can change up to 11.86% due to the change of location. Two-axis PV tracking offers a small improvement (about 4% on average) over single-vertical-axis tracking but offers noticeable improvement (about 34% on average) over optimally oriented fixed PV panels. Monthly profiles of expected PV electricity generation, as well as the generation drop due to changing the PV mounting from free standing to building integrated, were examined for three locations. As general perspectives that may be of interest to global readers, this work provides quantitative evidence of the overall accuracy of the PVGIS-SARAH database through comparison with ground-measured global horizontal irradiation (GHI). In addition, a full example is presented considering 12 different countries in the northern and southern hemispheres that brings the attention of solar energy modelers to the level of errors they may encounter when the impact of longitude (thus, the exact location) is ignored for simplicity, while focus is given to the latitude.

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Reconfigurable Distributed Power Electronics Technique for Solar PV Systems

Electronics ◽

10.3390/electronics10091121 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1121

Author(s):

Kamran Ali Khan Niazi ◽

Yongheng Yang ◽

Tamas Kerekes ◽

Dezso Sera

Keyword(s):

Energy Yield ◽

Solar Pv ◽

Charge Redistribution ◽

Pv System ◽

Partial Shading ◽

Pv Systems ◽

Simulation Based ◽

In Series ◽

A Cell ◽

Power Balancing

A reconfiguration technique using a switched-capacitor (SC)-based voltage equalizer differential power processing (DPP) concept is proposed in this paper for photovoltaic (PV) systems at a cell/subpanel/panel-level. The proposed active diffusion charge redistribution (ADCR) architecture increases the energy yield during mismatch and adds a voltage boosting capability to the PV system under no mismatch by connected the available PV cells/panels in series. The technique performs a reconfiguration by measuring the PV cell/panel voltages and their irradiances. The power balancing is achieved by charge redistribution through SC under mismatch conditions, e.g., partial shading. Moreover, PV cells/panels remain in series under no mismatch. Overall, this paper analyzes, simulates, and evaluates the effectiveness of the proposed DPP architecture through a simulation-based model prepared in PSIM. Additionally, the effectiveness is also demonstrated by comparing it with existing conventional DPP and traditional bypass diode architecture.

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Grid Parity of Residential Building Rooftop Solar PV in India

Strategic Planning for Energy and the Environment ◽

10.13052/spee1048-4236.39142 ◽

2021 ◽

pp. 19-40

Author(s):

Rakesh Dalal ◽

Kamal Bansal ◽

Sapan Thapar

Keyword(s):

Residential Building ◽

Solar Photovoltaic ◽

Solar Pv ◽

Indian Government ◽

Pv System ◽

Pv Systems ◽

Grid Parity ◽

Solar Pv System ◽

Utility Grid ◽

Rooftop Solar

Rooftop solar photovoltaic(PV) installation in India have increased in last decade because of the flat 40 percent subsidy extended for rooftop solar PV systems (3 kWp and below) by the Indian government under the solar rooftop scheme. From the residential building owner's perspective, solar PV is competitive when it can produce electricity at a cost less than or equal grid electricity price, a condition referred as “grid parity”. For assessing grid parity of 3 kWp and 2 kWp residential solar PV system, 15 states capital and 19 major cities were considered for the RET screen simulation by using solar isolation, utility grid tariff, system cost and other economic parameters. 3 kWp and 2 kWp rooftop solar PV with and without subsidy scenarios were considered for simulation using RETscreen software. We estimate that without subsidy no state could achieve grid parity for 2kWp rooftop solar PV plant. However with 3 kWp rooftop solar PV plant only 5 states could achieve grid parity without subsidy and with government subsidy number of states increased to 7, yet wide spread parity for residential rooftop solar PV is still not achieved. We find that high installation costs, subsidized utility grid supply to low energy consumer and financing rates are major barriers to grid parity.

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Estimation of Solar Irradiation on Inclined Surface Based on Web Databases

International Journal of Electronics and Telecommunications ◽

10.2478/eletel-2014-0041 ◽

2014 ◽

Vol 60 (4) ◽

pp. 315-320 ◽

Cited By ~ 3

Author(s):

Gustaw Mazurek

Keyword(s):

Solar Irradiation ◽

Pv System ◽

Solar Systems ◽

Pv Systems ◽

Pv Modules ◽

Tilted Plane ◽

Annual Scale ◽

Inclined Surface ◽

Long Operation ◽

Good Agreement

Abstract Estimation of Global Tilted Irradiation (GTI) is a key to performance assessment of typical solar systems since they usually employ tilted photovoltaic (PV) modules or collectors. Numerous solar radiation databases can deliver irradiation values both on horizontal and tilted plane, however they are validated mostly with horizontal-plane ground measurements. In this paper we have compared GTI estimates retrieved from five Internet databases with results of measurements at two PV systems located in Poland. Our work shows that in spite of good agreement in annual scale, there is a tendency to underestimate GTI in summer and overestimate in winter, when PV modules can receive less than a half of expected irradiation. The latter issue affects sizing of PV system components and implies a correction needed to achieve all-year long operation.

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Design and evalution of a solar PV system

Iraqi Journal of Physics (IJP) ◽

10.30723/ijp.v11i21.369 ◽

2019 ◽

Vol 11 (21) ◽

pp. 67-74

Author(s):

Imad Jawad Khadim

Keyword(s):

Energy Consumption ◽

Solar Irradiation ◽

System Efficiency ◽

Performance Parameters ◽

Solar Pv ◽

Pv System ◽

Electricity Grid ◽

Average System ◽

Solar Pv System ◽

Reduce Energy Consumption

PV connected systems are worldwide installed because it allows consumer to reduce energy consumption from the electricity grid. This paper presents the results obtained from monitoring a 1.1 kWp. The system was monitored for nine months and all the electricity generated was fed to the fifth floor for physics and renewable energy building 220 V, 50 Hz. Monthly, and daily performance parameters of the PV system are evaluated which include: average generated of system Ah per day, average system efficiency, solar irradiation around these months. The average generated kWh per day was 8 kWh/day, the average solar irradiation per day was 5.6 kWh/m2/day, the average inverter efficiency was 95%, the average modules efficiency was 12%.

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Optimal Penetration of Photovoltaic Systems in Distribution Networks

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.479-480.590 ◽

2013 ◽

Vol 479-480 ◽

pp. 590-594

Author(s):

Wei Lin Hsieh ◽

Chia Hung Lin ◽

Chao Shun Chen ◽

Cheng Ting Hsu ◽

Chin Ying Ho ◽

...

Keyword(s):

Power Generation ◽

Solar Energy ◽

Voltage Control ◽

Distribution Networks ◽

Solar Irradiation ◽

Total Power ◽

Pv System ◽

Pv Systems ◽

Power Injection ◽

Distribution Feeder

The penetration level of a PV system is often limited due to the violation of voltage variation introduced by the large intermittent power generation. This paper discusses the use of an active power curtailment strategy to reduce PV power injection during peak solar irradiation to prevent voltage violation so that the PV penetration level of a distribution feeder can be increased to fully utilize solar energy. When using the proposed voltage control scheme for limiting PV power injection into the study distribution feeder during high solar irradiation periods, the total power generation and total energy delivered by the PV system over a 1-year period are determined according to the annual duration of solar irradiation. With the proposed voltage control to perform the partial generation rejection of PV systems, the optimal installation capacity of PV systems can be determined by maximizing the net present value of the system so that better cost effectiveness of the PV project and better utilization of solar energy can be obtained.

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Reliability, Availability and Maintainability Analysis for Grid-Connected Solar Photovoltaic Systems

Energies ◽

10.3390/en12071213 ◽

2019 ◽

Vol 12 (7) ◽

pp. 1213 ◽

Cited By ~ 11

Author(s):

A. Sayed ◽

M. El-Shimy ◽

M. El-Metwally ◽

M. Elshahed

Keyword(s):

Block Diagram ◽

Solar Photovoltaic ◽

Solar Pv ◽

Pv System ◽

Safety Issues ◽

Pv Systems ◽

Area Of Interest ◽

Novel Approach ◽

Maintainability Analysis ◽

Ram Analysis

Recently, solar power generation is significantly contributed to growing renewable sources of electricity all over the world. The reliability and availability improvement of solar photovoltaic (PV) systems has become a critical area of interest for researchers. Reliability, availability, and maintainability (RAM) is an engineering tool used to address operational and safety issues of systems. It aims to identify the weakest areas of a system which will improve the overall system reliability. In this paper, RAM analysis of grid-connected solar-PV system is presented. Elaborate RAM analysis of these systems is presented starting from the sub-assembly level to the subsystem level, then the overall system. Further, an improved Reliability Block Diagram is presented to estimate the RAM performance of seven practical grid-connected solar-PV systems. The required input data are obtained from worldwide databases of failures, and repair of various subassemblies comprising various meteorological conditions. A novel approach is also presented in order to estimate the best probability density function for each sub-assembly. The monitoring of the critical subassemblies of a PV system will increase the possibility not only for improving the availability of the system, but also to optimize the maintenance costs. Additionally, it will inform the operators about the status of the various subsystems of the system.

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The Technical Challenges Facing the Integration of Small-Scale and Large-scale PV Systems into the Grid: A Critical Review

Electronics ◽

10.3390/electronics8121443 ◽

2019 ◽

Vol 8 (12) ◽

pp. 1443 ◽

Cited By ~ 3

Author(s):

Abdullah Alshahrani ◽

Siddig Omer ◽

Yuehong Su ◽

Elamin Mohamed ◽

Saleh Alotaibi

Keyword(s):

Large Scale ◽

Distribution Network ◽

Small Scale ◽

Energy Access ◽

Solar Pv ◽

Pv System ◽

Pv Systems ◽

Technical Challenges ◽

Technical Solutions ◽

The Impact

Decarbonisation, energy security and expanding energy access are the main driving forces behind the worldwide increasing attention in renewable energy. This paper focuses on the solar photovoltaic (PV) technology because, currently, it has the most attention in the energy sector due to the sharp drop in the solar PV system cost, which was one of the main barriers of PV large-scale deployment. Firstly, this paper extensively reviews the technical challenges, potential technical solutions and the research carried out in integrating high shares of small-scale PV systems into the distribution network of the grid in order to give a clearer picture of the impact since most of the PV systems installations were at small scales and connected into the distribution network. The paper reviews the localised technical challenges, grid stability challenges and technical solutions on integrating large-scale PV systems into the transmission network of the grid. In addition, the current practices for managing the variability of large-scale PV systems by the grid operators are discussed. Finally, this paper concludes by summarising the critical technical aspects facing the integration of the PV system depending on their size into the grid, in which it provides a strong point of reference and a useful framework for the researchers planning to exploit this field further on.

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Solar Concentrators In Malaysia: Towards The Development Of Low Cost Solar Photovoltaic Systems

Jurnal Teknologi ◽

10.11113/jt.v55.914 ◽

2012 ◽

Author(s):

Firdaus Muhammad Sukki ◽

Roberto Ramirez Iniguez ◽

Scott G. Mcmeekin ◽

Brian G. Stewart ◽

Barry Clive

Keyword(s):

Financial Analysis ◽

Low Cost ◽

Good Alternative ◽

Solar Photovoltaic ◽

Solar Pv ◽

Financial Benefit ◽

Pv System ◽

Solar Concentrators ◽

Pv Systems ◽

Solar Pv System

Solar energy has become a matter of global attention in the past few years. This paper explores the use and benefit of solar concentrators in the solar photovoltaic (PV) systems. First, a short literature review of previous research on the usage of solar concentrators in improving solar PV system performance and reducing the cost of implementation is presented. This is followed by an overview of SolarBrane, an example of a Building Integrated photovoltaic (BIPV) system which uses an optical concentrator in the solar PV design. An optimised design of the SolarBrane is also discussed afterwards. A financial benefit study is conducted to compare the average return of investment of using the optimised SolarBrane and traditional solar PV installed in Malaysia’s environment. SolarBrane has proven to be a good alternative to achieve costeffective solar PV system. The financial analysis simulated under the new Malaysian Feed–In Tariff scheme indicates that the optimised SolarBrane could potentially reduce the initial cost of implementation by 40% and generate higher return, close to 20%, when compared to traditional solar PV systems. Key words: Solar photovoltaic; solar concentrator; solarBrane; dielectric totally internally reflecting concentrator; financial analysis

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