Computer simulation of shading effects in photovoltaic arrays

Alonso-García, Montserrat; Ruiz, José María Ruiz; Herrmann, W.

doi:10.1016/j.renene.2005.09.030

Cited by 140 publications

(60 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Previous studies indicate that shading losses could reduce average PV output by 4-7% [25,26] but the instantaneous drop on a module level could be even much higher [27]. In practice is it almost impossible to determine accurately the influence of shading on the PV output as this would necessitate knowing the exact topology of the buildings and the city plan.…”

Section: Effect Of Shadingmentioning

confidence: 99%

Effects of large-scale photovoltaic power integration on electricity distribution networks

Paatero¹,

Lund²

2007

Renewable Energy

217

View full text Add to dashboard Cite

The public support in PV technologies and increasing markets have resulted in extensive applications of grid-connected PV, in particular in the consumer side and electricity distribution grid. In this paper the effects of a high level of grid connected PV in the middle voltage distribution network have been analyzed. The emphasis is put on static phenomena, including voltage drop, network losses and grid benefits. A multipurpose modeling tool is used for PV analysis in Lisbon and Helsinki climates. All network types studied can handle PV without problems with an amount of PV equaling at least up to the load (1kW p /household). The comb-type network showed the best performance. The PV is unable to shave the domestic load peak in the early evening hours but through orientating the PV panels both to east and west, the noon peak from PV can be reduced by 30 %. PV integration reduces network losses positively up to a 1kW p /hh (100% of annual domestic load) level. For 2 kW p /hh all but the comb-type networks demonstrate clear over-voltage situations and the annual network losses are much higher than without PV.

show abstract

Section: Effect Of Shadingmentioning

confidence: 99%

Effects of large-scale photovoltaic power integration on electricity distribution networks

Paatero¹,

Lund²

2007

Renewable Energy

217

View full text Add to dashboard Cite

show abstract

“…The lower or optimistic bound assumes that power losses due to shadows are proportional to the shaded beam radiation. Several references [13,14,16,17,18] show the complexity and limits associated with the electrical models of shaded generators. Thus, the generalization of the variety of cases comprised between these two bounds is not easily feasible (although some experimental models have been already proposed [19]).…”

Section: Shadows and Productivitymentioning

confidence: 99%

Cost of energy and mutual shadows in a two-axis tracking PV system

David¹

2012

Renewable Energy

View full text Add to dashboard Cite

The performance improvement obtained from the use of trackers in a PV system cannot be separated from the higher requirement of land due to the mutual shadows between generators. Thus, the optimal choice of distances between trackers is a compromise between productivity and land use to minimize the cost of the energy produced by the PV system during its lifetime. This paper develops a method for the estimation and optimization of the cost of energy function. It is built upon a set of equations to model the mutual shadows geometry and a procedure for the optimal choice of the wire cross-section. Several examples illustrate the use of the method with a particular PV system under different conditions of land and equipment costs.This method is implemented using free software available as supplementary material.Keywords: mutual shadows, two-axis tracking, productivity, grid-connected PV system, numerical optimization Nomenclature bAspect ratio (length-width) of a tracker. B e fEffective direct irradiation (irradiance) incident on a PV generator. C ECost of the energy produced by a PV system during its lifetime (€/kWh).C P Cost of the PV system including maintenance costs (€). D e fEffective diffuse irradiation (irradiance) incident on a PV generator.Circumsolar fraction of the effective diffuse irradiance.Isotropic fraction of the effective diffuse irradiance. E ACEnergy produced by a PV system during its lifetime (kWh).γ s Altitude sun angle.

show abstract

“…Comparisons have been made between actual measurements and predicted results and the main focus of the study is the quantification of shading. A number of previous studies have examined the impact of shading on the performance of PV installations but the vast majority of these studies have examined the impact of shading on the performance of the PV modules themselves, and the resulting reduction in electrical output, rather than an assessment of the general impact of shading on incident solar radiation and the electrical output of individual domestic system installations (Alonso-Garcia et al 2006 andWoyte et al 2003). Work by Murphy et al (2009) evaluated the simulation of PV installations using the SAP 2005 model and concluded that whilst there is less scope for errors when compared to more detailed models such as PVSYST, specific PV system data cannot be modeled, nor can site location be specified which leads to the SAP model over-predicting PV output for all UK locations North of Sheffield, and underpredicting PV output for locations further South.…”

Section: Introductionmentioning

confidence: 99%

A Comparison of Computational Simulation and Physical Measurement of Solar Radiation and Photovoltaic Outputs for Residential Dwellings

Pretlove

Osborne

2015

Renewable Energy in the Service of Mankind Vol I

View full text Add to dashboard Cite

By 2016, new residential buildings in the UK will have to be 'net zero carbon' to comply with proposed changes to Part L of the Government's Building Regulations. Approved document Part L of the Building Regulations requires energy use and generation, and the resulting carbon emissions, to be quantified using the Government's Standard Assessment Procedure (SAP) model. To achieve a zero carbon dwelling, on-site renewable technologies must usually be incorporated into the design. Since the introduction of the Feed-In Tariff (FIT), in April 2010, photovoltaic (PV) systems have been seen as one of the most cost effective methods of achieving the higher levels of the Code for Sustainable Homes (CfSH), the route to meet zero carbon emissions in domestic buildings. The quantification of energy generation for CfSH certification, comes directly from the SAP model, where the methodology used to justify the use of PV systems is crude in its prediction of shading and utilises simplified rules-of-thumb to predict how shading will affect energy generation. This paper compares the prediction methods currently available to designers (SAP) against real data collected on live building projects in South West London. Included in this study is the physical measurement of solar radiation where PV panels will be installed at a later date, together with the measured outputs from two recent domestic PV installations that are benefiting from the FIT initiative. For both of these, in terms of solar radiation and electricity production, comparisons are made between actual measurements and predicted results. The results of this study show that the methodology provided in the SAP 2005 and 2009 models for determining the available energy at inverter output (kWh/year) for solar PV systems is crude and inaccurate, particularly in locations where there is significant shading from external obstructions, and particularly where an evaluation of the overshading is required. The SAP methodology for quantifying the shading coefficient is crude and there are little guideline provided. A novel technique for quantifying overshading has been tested in this study and the results indicate that a more robust method is required. The methodology being proposed is in line with more comprehensive approaches that have been adopted by other organisations, in particular new guidelines and methodologies published and recommended by the Microgeneration Certification Scheme (MCS). Proposals by the BRE for improvements to the SAP 2012 model, for the calculation of incident solar radiation, and the energy generated by a solar PV system, are generally positive but the determination of overshading in any particular location remains crude and difficult to quantify.

show abstract

Computer simulation of shading effects in photovoltaic arrays

Cited by 140 publications

References 6 publications

Effects of large-scale photovoltaic power integration on electricity distribution networks

Effects of large-scale photovoltaic power integration on electricity distribution networks

Cost of energy and mutual shadows in a two-axis tracking PV system

A Comparison of Computational Simulation and Physical Measurement of Solar Radiation and Photovoltaic Outputs for Residential Dwellings

Contact Info

Product

Resources

About