A6_calcShd {solaR}R Documentation

Shadows on PV systems.

Description

Compute the irradiance and irradiation including shadows for two-axis and horizontal N-S axis trackers and fixed surfaces. It makes use of the function fSombra for the shadows factor calculation. It is used by the function calcGef.

Usage


calcShd(radEf, modeTrk = 'fixed', modeShd = '',
        struct = list(),
        distances = data.frame())

Arguments

radEf

A Gef object. It may be the result of the calcGef function.

modeTrk

character, to be chosen from 'fixed', 'two' or 'horiz'. When modeTrk = 'fixed' the surface is fixed (inclination and azimuth angles are constant). The performance of a two-axis tracker is calculated with modeTrk = 'two', and modeTrk = 'horiz' is the option for an horizontal N-S tracker. Its default value is modeTrk = 'fixed'

modeShd

character, defines the type of shadow calculation. In this version of the package the effect of the shadow is calculated as a proportional reduction of the circumsolar diffuse and direct irradiances. This type of approach is selected with modeShd = 'area'. In future versions other approaches which relate the geometric shadow and the electrical connections of the PV generator will be available. If modeTrk = 'horiz' it is possible to calculate the effect of backtracking with modeShd = 'bt'. If modeShd = c('area','bt') the backtracking method will be carried out and therefore no shadows will appear. Finally, for two-axis trackers it is possible to select modeShd = 'prom' in order to calculate the effect of shadows on an average tracker (see fSombra6). The result will include three variables (Gef0, Def0 and Bef0) with the irradiance/irradiation without shadows as a reference.

struct

list.

When modeTrk = 'fixed' or modeTrk = 'horiz' only a component named L, which is the height (meters) of the tracker, is needed.

For two-axis trackers (modeTrk = 'two'), an additional component named W, the width of the tracker, is required. Moreover, only when modeTrk = 'two' two components named Nrow and Ncol are included under this list. These components define, respectively, the number of rows and columns of the whole set of two-axis trackers in the PV plant.

distances

data.frame.

When modeTrk = 'fixed' it includes a component named D for the distance between fixed surfaces. An additional component named H can be included with the relative height between surfaces.

When modeTrk = 'horiz' it only includes a component named Lew, being the distance between horizontal NS trackers along the East-West direction.

When modeTrk = 'two' it includes a component named Lns being the distance between trackers along the North-South direction, a component named Lew, being the distance between trackers along the East-West direction and a (optional) component named H with the relative height between surfaces.

The distances, in meters, are defined between axis of the trackers.

Value

A Gef object including three additional variables (Gef0, Def0 and Bef0) in the slots GefI, GefD, Gefdm and Gefy with the irradiance/irradiation without shadows as a reference.

Author(s)

Oscar Perpiñán Lamigueiro.

References

See Also

calcG0, fTheta, fInclin, calcShd.

[Package solaR version 0.46 Index]