C_fTheta {solaR}R Documentation

Angle of incidence of solar irradiation on a inclined surface

Description

The orientation, azimuth and incidence angle are calculated from the results of fSolI or calcSoland from the information supplied by the arguments beta and alfa when the surface is fixed (modeTrk = 'fixed') or the movement equations when a tracking surface is chosen (modeTrk = 'horiz' or modeTrk = 'two'). Besides, the modified movement of a horizontal NS tracker due to the backtracking strategy is calculated if BT = TRUE with information about the tracker and the distance between the trackers included in the system.

This function is used by the calcGef function.

Usage

fTheta(sol, beta, alfa = 0, modeTrk = "fixed", betaLim = 90,
    BT = FALSE, struct, dist)

Arguments

sol

Sol object as provided by calcSol.

beta

numeric, inclination angle of the surface (degrees). It is only needed when modeTrk = 'fixed'.

alfa

numeric, azimuth angle of the surface (degrees). It is measured from the south (alfa = 0), and it is negative to the east and positive to the west. It is only needed when modeTrk = 'fixed'. Its default value is alfa = 0 (surface facing to the south).

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'

betaLim

numeric, maximum value of the inclination angle for a tracking surface. Its default value is 90 (no limitation))

BT

logical, TRUE when the bactracking technique is to be used with a horizontal NS tracker, as described by Panico et al. (see References). The default value is FALSE. In future versions of this package this technique will be available for two-axis trackers.

struct

Only needed when BT = TRUE. A list, with a component named L, which is the height (meters) of the tracker. In future versions the backtracking technique will be used in conjuction with two-axis trackers, and a additional component named W will be needed.

dist

Only needed when BT = TRUE. A data.frame, with a component named Lew, being the distance between the horizontal NS trackers along the East-West direction. In future versions an additional component named Lns will be needed for two-axis trackers with backtracking.

Value

A zoo object with these components:

Beta

numeric, inclination angle of the surface (radians). When modeTrk = 'fixed' it is the value of the argument beta converted from degrees to radians.

Alfa

numeric, azimuth angle of the surface (radians). When modeTrk = 'fixed' it is the value of the argument alfa converted from degrees to radians.

cosTheta

numeric, cosine of the incidence angle of the solar irradiance on the surface

Author(s)

Oscar Perpiñán Lamigueiro.

References

See Also

fInclin, fSombra, calcGef.

[Package solaR version 0.46 Index]