Spectral Mismatch Correlated With Air Mass Under Varying Clear Sky Conditions for Photovoltaic Facilities With Crystalline-Silicon Modules: Solar Spectral Effects — An EPC Contractor’s Perspective

Author(s):  
Paul Johnston

Photovoltaic utility-scale grid-connected power generation facilities have performance guarantee bases that often include a reference solar spectrum. EPC contractors are obligated to correct tested performance for solar spectrum, as is done for irradiance and cell temperature, to judge whether contractual performance guarantees have been satisfied. Air mass correlated with solar spectral irradiance offers a convenient way of accomplishing this. This paper offers an improvement in the versatility and accuracy of accounting for spectral effects in this manner. The effects on the spectral composition by atmospheric constituents, like aerosols and water vapor, are investigated. Spectral mismatch curves are derived that characterize the responses of the PV modules and the irradiance measurement device to both the estimated test and the reference solar spectra. Comparison of several supplier performance curves and spectral mismatch curves reveals significant discrepancies. An improvement in accuracy is proposed by the use of supplier spectral response data and estimated solar spectral profiles. Correcting for spectral effects has minimal impact at air mass values near the 1.5 reference value, but grows in significance with increasing air mass. Greater precision in accounting for solar spectral effects on PV plant performance is expected as this segment of the power generation industry matures. This paper proposes a methodology that addresses this expectation.

2021 ◽  
Author(s):  
Mohammad Aminul Islam ◽  
Nabilah M. Kassim ◽  
Ammar Ahmed Alkahtani ◽  
Nowshad Amin

The performance of photovoltaic (PV) solar cells is influenced by solar irradiance as well as temperature. Particularly, the average photon energy of the solar spectrum is different for low and high light intensity, which influences the photocurrent generation by the PV cells. Even if the irradiance level and the operating temperature remain constant, the efficiency will still depend on the technological parameters of the PV cell, which in turn depends on the used PV material’s absorption quality and the spectral responsivity and cell structure. This study is devoted to the review of different commercially available technologies of PV cells include crystalline silicon (c-Si), polycrystalline silicon (pc-Si), cadmium telluride (CdTe), and copper indium gallium selenide (CIGS). We tried to correlate the spectral response or the photocurrent of different PV cells with the variations of the solar spectrum, environmental conditions, and the material properties and construction of PV cells.


2021 ◽  
Vol 292 ◽  
pp. 01021
Author(s):  
Gao Sheng ◽  
Lu Xiaodong ◽  
Lun Shuxian

Under standard test conditions, the spectral irradiance of artificial solar light sources and the spectral response of photovoltaic devices are important factors that affect the accuracy of device test results. This paper takes the standard solar spectrum AM1.5 as a reference, and calculates the difference between the four commonly used artificial solar light sources (Arc Lamp, Q-Flash, Q-Flash w and ELH) and the standard solar spectrum AM1.5 from the perspective of spectral mismatch. The spectral mismatch factor and the output parameters of the amorphous silicon cell under the irradiation of these light sources. Calculations show that the spectral mismatch factor of Arc Lamp is only 1.005, which matches the standard solar spectrum AM1.5 best. Due to the effect of spectral mismatch, the output parameters of amorphous silicon cells will change significantly after different artificial light sources irradiate them.


2021 ◽  
Author(s):  
Geoffrey S Kinsey ◽  
Matthew Boyd ◽  
Marília Braga ◽  
Nicholas C. Riedel-Lyngskær ◽  
Raul R. Cordero ◽  
...  

In comparisons of solar photovoltaic performance, variation in the spectrum of sunlight is infrequently considered. A single spectrum, AM1.5, is used as the standard condition both for comparison of competing solar cell technologies and evaluation of energy generation from solar power plants. The addition of solar spectrum variation provides a more relevant basis for comparison and reduces prediction error and its financial impacts. Ground-level measurements collected worldwide have been pooled to provide an extensive – though by no means comprehensive – sampling of the global variation in spectral irradiance. Applied to nine solar cell types, the resulting variation in solar cell performance indicates that a single spectrum is not sufficient for comparison of cells with different spectral responses. The performance of different cell types diverges from that under standard conditions. Increases in the degree of sun tracking decrease efficiency for cells with a narrow spectral response. Cells with two or more junctions tend to have efficiencies below that obtained under AM1.5. Of the nine cell types, silicon exhibits the least spectral sensitivity: the median relative variation at a single site is 3%.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sangho Kim ◽  
Thanh Thuy Trinh ◽  
Jinjoo Park ◽  
Duy Phong Pham ◽  
Sunhwa Lee ◽  
...  

AbstractWe developed and designed a bifacial four-terminal perovskite (PVK)/crystalline silicon (c-Si) heterojunction (HJ) tandem solar cell configuration albedo reflection in which the c-Si HJ bottom sub-cell absorbs the solar spectrum from both the front and rear sides (reflected light from the background such as green grass, white sand, red brick, roofing shingle, snow, etc.). Using the albedo reflection and the subsequent short-circuit current density, the conversion efficiency of the PVK-filtered c-Si HJ bottom sub-cell was improved regardless of the PVK top sub-cell properties. This approach achieved a conversion efficiency exceeding 30%, which is higher than those of both the top and bottom sub-cells. Notably, this efficiency is also greater than the Schockley–Quiesser limit of the c-Si solar cell (approximately 29.43%). The proposed approach has the potential to lower industrial solar cell production costs in the near future.


2020 ◽  
Vol 29 ◽  
pp. 8-14
Author(s):  
Manal Midhat Abdullah ◽  
Omar Adnan Ibrahim

Core-shell nanocrystals are utilized to improve vitality conversion efficiency of Si based solar cells. In the present work, a study of synthesis and characterization of photo luminescent, down-shifting, core-shell CdSe/CdS quantum dots is introduced. The QD,s absorb in the UV range (350nm) of the solar spectrum and emit photons with wavelengths centered at (574 nm). Calculated energy gap is (2.16 eV), which is well suited for Silicon absorption and electron-hole pair generation. The grain size is ranged between (1.814 and 3.456 nm). Results show that the cell efficiency is improved from (8.81%) (For a reference silicon solar cell) to (10.07%) (For a CdSe/CdS QD deposited directly on the surface of the solar cell). This improvement is referred to the spreading of the absorbed solar radiation over the spectral response of the Si solar cell.


Author(s):  
Kurt Plotts ◽  
Evangelos Diatzikis

Siemens has been on the cutting edge of the power generation business for over a century and has been providing diagnostics systems design and implementation since the early 1980s. Siemens Power Diagnostics® Services is designed to maximize plant performance, availability and profitability. Engineering knowledge, combined with the use of sophisticated tools, provides trending and analysis capabilities to address a broad range of operating needs specific to each customer. The goal of Power Diagnostics® is to enhance Siemens assistance to our customers through the detection of impending operational problems thereby helping to minimize unplanned outages and maximize power generation availability. A variety of new technologies are being harnessed to further this goal. A survey and discussion of these technologies will be the goal of this paper. Some of the projects discussed will be; Advances in the Power Plant Automated Diagnostics Systems, Blade Vibration Monitor (BVM), Fiber Optic Vibration Monitor (FOVM), and the Radio Frequency Monitor (RFM). The development and verification phases of research projects have often been conducted at customer sites. Many aspects of these technologies are new and will be of interest to gas turbine engineers as they are not widely applied yet. It is hoped that the reader will gain a new appreciation for the scope of modern diagnostic methods for power generation systems.


2021 ◽  
Author(s):  
Martin Snow ◽  
Stephane Beland ◽  
Odele Coddington ◽  
Steven Penton ◽  
Don Woodraska

<p>The GOES-R series of satellites includes a redesigned instrument for solar spectral irradiance: the Extreme ultraviolet and X-ray Irradiance Sensor (EXIS).  Our team will be using a high-cadence broadband visible light diode to construct a proxy for Total Solar Irradiance (TSI).  This will have two advantages over the existing TSI measurements:  measurements are taken at 4 Hz, so the cadence of our TSI proxy is likely faster than any existing applications, and the observations are taken from geostationary orbit, so the time series of measurements is virtually uninterrupted.  Calibration of the diode measurements will still rely on the standard TSI composites.  </p><p>The other measurement from EXIS that will be used is the Magnesium II core-to-wing ratio.  The MgII index is a proxy for chromospheric activity, and is measured by EXIS every 3 seconds.  The combination of the two proxies can be used to generate a model of the full solar spectrum similar to the NRLSSI2 empirical model.</p><p>We are in the first year of a three-year grant to develop the TSI proxy and the SSI model, so only very preliminary findings will be discussed in this presentation.</p>


Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1268 ◽  
Author(s):  
Ana-Maria Cormos ◽  
Simion Dragan ◽  
Letitia Petrescu ◽  
Vlad Sandu ◽  
Calin-Cristian Cormos

Decarbonization of energy-intensive systems (e.g., heat and power generation, iron, and steel production, petrochemical processes, cement production, etc.) is an important task for the development of a low carbon economy. In this respect, carbon capture technologies will play an important role in the decarbonization of fossil-based industrial processes. The most significant techno-economic and environmental performance indicators of various fossil-based industrial applications decarbonized by two reactive gas-liquid (chemical scrubbing) and gas-solid CO2 capture systems are calculated, compared, and discussed in the present work. As decarbonization technologies, the gas-liquid chemical absorption and more innovative calcium looping systems were employed. The integrated assessment uses various elements, e.g., conceptual design of decarbonized plants, computer-aided tools for process design and integration, evaluation of main plant performance indexes based on industrial and simulation results, etc. The overall decarbonization rate for various assessed applications (e.g., power generation, steel, and cement production, chemicals) was set to 90% in line with the current state of the art in the field. Similar non-carbon capture plants are also assessed to quantify the various penalties imposed by decarbonization (e.g., increasing energy consumption, reducing efficiency, economic impact, etc.). The integrated evaluations exhibit that the integration of decarbonization technologies (especially chemical looping systems) into key energy-intensive industrial processes have significant advantages for cutting the carbon footprint (60–90% specific CO2 emission reduction), improving the energy conversion yields and reducing CO2 capture penalties.


1994 ◽  
Vol 143 ◽  
pp. 72-72 ◽  
Author(s):  
Guenter Brueckner ◽  
Linton E. Floyd ◽  
Paul A. Lund ◽  
Dianne K. Prinz ◽  
Michael E. Vanhoosier

The SUSIM (Solar Ultraviolet Spectral Irradiance Monitor) on board the UARS (Upper Atmosphere Research Satellite) has measured the solar UV output from 120 nm to 400 nm on a daily basis since October 1991. A reference channel records a solar spectrum semi-annually only to reduce the instrument degradation of this channel and to provide long-term stability marks. Four deuterium lamps are used at monthly, semi-annual and annual intervals to provide long term calibration of the instrument. A preliminary analysis of the long term stability of SUSIM-UARS indicates that the precision of the instrument should be better than a few percent. The repeatability of two scans is better than 0.2%. A simplified SUSIM instrument is flying on NASA’s ATLAS Spacelab missions anually to provide calibration points for the SUSIM-UARS.


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