Shadow effect of adjacent solar collectors in large scale systems

Appelbaum, J.; Bany, J.

doi:10.1016/0038-092x(79)90073-2

Cited by 115 publications

(41 citation statements)

References 2 publications

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“…The shading limit angle, γ(φ), depends on the row-to-row pitch, P, the array width, W, the position along the array width (measured from the bottom), x, and the array tilt angle [6]:…”

Section: A Isotropic Diffuse Modelmentioning

confidence: 99%

Diffuse shading losses in tracking photovoltaic systems

Westbrook

Reusser

Collins

2014

2014 IEEE 40th Photovoltaic Specialist Conference (PVSC)

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Shading losses of the diffuse irradiance component occur when objects block a portion of the sky view of a solar collector. Accurate PV system performance modeling must include a consideration of diffuse shading losses. Because of the difficulties in predicting the anisotropic distribution of the diffuse irradiance, existing models of diffuse shading necessarily contain simplifying assumptions. Scant published research has examined whether commonly-used models for diffuse shading provide a reasonable fit to field measurements for PV systems. We present the derivation of a three-dimensional diffuse shading model, examine the implications for diffuse shading losses, and discuss results from over five months of experimental measurements of diffuse shading for a tracking system in Colorado.Index Terms -photovoltaic systems, power system modeling, solar power generation, system performance.

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“…The shading limit angle, γ(φ), depends on the row-to-row pitch, P, the array width, W, the position along the array width (measured from the bottom), x, and the array tilt angle [6]:…”

Section: A Isotropic Diffuse Modelmentioning

confidence: 99%

Diffuse shading losses in tracking photovoltaic systems

Westbrook

Reusser

Collins

2014

2014 IEEE 40th Photovoltaic Specialist Conference (PVSC)

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“…Hourly values for irradiance, cell temperature, and solar position are calculated by NREL's System Advisor Model (SAM) for an array of Yingli YL250P-29b 60-cell modules in Sacramento, CA [13]. Shading is calculated from solar position according to [14]. Hourly irradiance is reduced by diffuse irradiance loss as described below.…”

Section: A Simulation Toolmentioning

confidence: 99%

Performance of differential power-processing submodule DC-DC converters in recovering inter-row shading losses

Doubleday

Deline

Olalla

et al. 2015

2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC)

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Large commercial photovoltaic systems suffer a regular and predictable energy loss due to both inter-row shading and reduced diffuse irradiance in tightly spaced arrays. This paper investigates the advantages of replacing bypass diodes with submodule-integrated DC-DC converters (subMICs) to mitigate these losses. Yearly simulations of commercial-scale PV systems were conducted considering two subMIC granularities and a range of row-to-row pitches given either a fixed array size or a fixed land area. Results show subMIC-enhanced systems can recover 35-48% of the total energy loss. In very tightly-spaced arrays, subMICS rated at 100% of maximum substring power can confer a 7% increase in annual energy output while powerlimited subMICs rated at 30% or 15% of maximum substring power still provide a 6% or 3-4% increase, respectively.

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“…The fraction of a solar array that is covered by shadows, often defined as the 'shade factor', is discussed in numerous articles [1][2][3][4][5][6][7][8]. Many of these articles invoke different models for diffuse irradiance, some consider tracking modules, and some consider shade from fences, trees, poles, or neighboring modules.…”

Section: Introductionmentioning

confidence: 98%

“…Many of these articles invoke different models for diffuse irradiance, some consider tracking modules, and some consider shade from fences, trees, poles, or neighboring modules. However none of the models in references [1][2][3][4][5][6][7][8] incorporate the nonlinear response of solar modules to partial shade.…”

Section: Introductionmentioning

confidence: 98%

A simple non-linear model for the effect of partial shade on PV systems

Thakkar

Cormode

Lonij

et al. 2010

2010 35th IEEE Photovoltaic Specialists Conference

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The effect of shade from one PV module on another is incorporated into a model for the power generated by PV systems. The model is calibrated with data from the Tucson Electric Power solar test yard. Shade de-rating factors from the model are compared with data every minute of the day and every day of the year. The model is then used to predict final yields (kWh/kWoc) for different PV system deployments with various (non-tracking) module orientations and ground-cover ratios. Several heuristics are put forth to help understand how the observed non-linear response to shade can impact the yield from PV systems. In one example, we find that a PV system deployed in the Tucson Electric Power solar test yard could produce 22% more kWh for the month of December (and 3.8% more annually) if the modules were separated by twice as much distance. In another example, we predict that a system in Tucson with south-facing modules at 12-degrees from horizontal can generate 1.5 times as many kWhlyr per square-meter of land compared to a system with modules at 32-degrees (the latitude angle).These examples emphasize the non-linear impact of partial shade on PV system performance.

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Shadow effect of adjacent solar collectors in large scale systems

Cited by 115 publications

References 2 publications

Diffuse shading losses in tracking photovoltaic systems

Diffuse shading losses in tracking photovoltaic systems

Performance of differential power-processing submodule DC-DC converters in recovering inter-row shading losses

A simple non-linear model for the effect of partial shade on PV systems

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