Studying the effect of spectral variations intensity of the incident solar radiation on the Si solar cells performance

Solar spectral variation is important in characterization of photovoltaic devices. We present results of an experimental investigation of the effects of the daily spectral variation on the device performance of multicrystalline silicon photovoltaic module. The investigation concentrate on the analysis of outdoor solar spectral measurements carried out at 1 min intervals on clear sky days. Short circuit current and open circuit voltage have been measured to describe the module electrical performance. We have shown that the shift in the solar spectrum towards infrared has a negative impact on the device performance of the module. The spectral bands in the visible region contribute more to the short circuit current than the bands in the infrared region while the ultraviolet region contributes least. The quantitative effect of the spectral variation on the performance of the photovoltaic module is reflected on their respective device performance parameters. The decrease in the visible and the increase in infrared of the radiation spectra account for the decreased current collection and hence power of the module

Realworld maximum power point tracking simulation of PV system based on Fuzzy Logic control

In the recent years, the solar energy becomes one of the most important alternative sources of electric energy, so it is important to improve the efficiency and reliability of the photovoltaic (PV) systems. Maximum power point tracking (MPPT) plays an important role in photovoltaic power systems because it maximize the power output from a PV system for a given set of conditions, and therefore maximize their array efficiency. This paper presents a maximum power point tracker (MPPT) using Fuzzy Logic theory for a PV system. The work is focused on the well known Perturb and Observe (P&O) algorithm and is compared to a designed fuzzy logic controller (FLC). The simulation work dealing with MPPT controller; a DC/DC Ćuk converter feeding a load is achieved. The results showed that the proposed Fuzzy Logic MPPT in the PV system is valid

Practical Investigation for Road Lighting using Renewable Energy Sources

Abstract - Hybrid renewable energy systems are recently used to counteract the limitations of solar and wind as solo renewable energy sources due to adverse weather conditions. This study explains a design of a fully independent -off grid- hybrid solar and wind road lighting system according to geography and weather conditions recorded from the National Research Institute of Astronomy and Geophysics. The computerized model is designed step by step by the aid of Simulink-Matlab and the simulation was successfully run to show the performance of each module

Design of a building-scale space solar cooling system using TRNSYS

Research into solar absorption chillers despite their environmental benefits has been limited to date to mainly larger systems whilst ignoring smaller building-scale units, which can significantly benefit from the use of optimally designed, low concentrating, non-imaging optical reflectors. A solar absorption chiller system designed to provide year-round space cooling for a typical primary health care facility in Cairo, Egypt, was designed to match local ambient, solar, and occupancy conditions, its performance simulated and then optimized to minimize auxiliary power consumption using the TRNSYS18 software, TRNOPT. Different configurations of collector types, array areas, storage sizes and collector slopes were used to determine the optimum specifications for the system components. Non-concentrating Evacuated Tube Collectors (ETCs) were compared with the same Evacuated Tube Collectors but integrated with external Compound Parabolic Concentrators (CPCs) with a geometric concentration ratio of 1.5X for supplying thermal energy to the single-effect absorption chiller investigated. This paper describes a user-friendly methodology developed for the design of solar heat-powered absorption chillers for small buildings using TRNSYS18 employing the Hookes–Jeeves algorithm within the TRNOPT function. Clear steps to avoid convergence problems when using TRNSYS are articulated to make repeatability for different systems and locations more straightforward. Collector array areas were varied from 30 m2 to 160 m2 and the size of the water-based thermal storage from 1 m3 to 3 m3 to determine the configuration that can supply the maximum solar fraction of the building’s cooling requirements for the lowest lifetime cost. The optimum solar fraction for ETCs and CPCs was found to be 0.66 and 0.94, respectively. If the current air conditioning demand is met through adoption of the CPC-based solar absorption systems this can potentially save the emission of 3,966,247 tCO2 per annum

Statistical Study of Confined Filament/Prominence Eruptions during Solar Cycle 23

International audienceFilament/prominence eruptions can have a significant impact on Earth's upper atmosphere and space environment, and are the primary drivers of what is now called space weather. To distinguish the different types of filament eruptions we statistically examine them during the 23rd Solar cycle. In this study we use 159 filament eruptions using the List of interplanetary (IP) Shocks Observed during Solar Cycle 23 (May 1996-January 2008) and their Source Information Environmental Satellites (GOES) X-ray plots (see Gopalswamy et al. [ 15 ]). It is found that 69% of the filament eruptions are confined eruptions, while 31% are ejective eruptions. Confined eruptions are 110 and 34 events (21%). They are due to active filaments and 76 events (48%) are due to disappearing filaments. The occurrences of active and disappearing filaments during the increasing phase of solar cycle 23 is found to be 80% while in the decreasing phase they are 13%. We have found that the dominant X-ray flare energy of confined eruptions is that of C class. The most common filaments field extent is located between 5 and 15 degrees. The most common flare duration is between 16 and 40 minutes

The Space Weather & Ultraviolet Solar Variability Microsatellite Mission (SWUSV)

International audienceWe present a summary of the scientific objectives, payload and mission profile of the Space Weather & Ultraviolet Solar Variability Microsatellite Mission (SWUSV) proposed to CNES and ESA (small mission)

The Space Weather and Ultraviolet Solar Variability (SWUSV) Microsatellite Mission

International audienceWe present the ambitions of the SWUSV (Space Weather and Ultraviolet Solar Variability) Microsatellite Mission that encompasses three major scientific objectives: (1) Space Weather including the prediction and detection of major eruptions and coronal mass ejections (Lyman-Alpha and Herzberg continuum imaging); (2) solar forcing on the climate through radiation and their interactions with the local stratosphere (UV spectral irradiance from 180 to 400 nm by bands of 20 nm, plus Lyman-Alpha and the CN bandhead); (3) simultaneous radiative budget of the Earth, UV to IR, with an accuracy better than 1% in differential. The paper briefly outlines the mission and describes the five proposed instruments of the model payload: SUAVE (Solar Ultraviolet Advanced Variability Experiment), an optimized telescope for FUV (Lyman-Alpha) and MUV (200-220 nm Herzberg continuum) imaging (sources of variability); UPR (Ultraviolet Passband Radiometers), with 64 UV filter radiometers; a vector magnetometer; thermal plasma measurements and Langmuir probes; and a total and spectral solar irradiance and Earth radiative budget ensemble (SERB, Solar irradiance & Earth Radiative Budget). SWUSV is proposed as a small mission to CNES and to ESA for a possible flight as early as 2017-2018