ghi_decomposition: Irradiance decomposition

In energyRt/merra2ools: R-tools to process MERRA-2 data (NASA) with focus on renewable energy

Irradiance decomposition

Description

Irradiance decomposition

Usage

ghi_decomposition(
  x,
  yday = "yday",
  GHI = "SWGDN",
  zenith = "zenith",
  beam = "beam",
  method = 0,
  zenith_max = 89,
  keep.all = FALSE,
  verbose = getOption("merra2.verbose")
)

Arguments

x
yday	day of a year, integer vector
GHI	Global Horizontal Irradiance from MERRA-2 subset (\mjseqnGHI, W/m^2)
zenith	Zenith angle, degrees
beam
method
zenith_max
keep.all
verbose

Details

\loadmathjax

List or data.frame with estimated following solar geometry variables:

• Extraterrestrial irradiance (\mjseqnG_e) \mjsdeqnG_e = G_sc\times\big(1+0.033\cos(\frac360n365)\big) where:
  \mjseqnG_sc = 1360.8W/m^2, is the solar constant based on the latest NASA observation (Kopp and Lean, 2011);
  \mjseqnn - day of the year.
  

• Clearness index (\mjseqnk_t) \mjsdeqnk_t = \fracGHIG_e\cos(zenith)

• Diffuse fraction (\mjseqnk_d) \mjsdeqnk_d = \begincases 1-0.09k_t & & k_t < 0.22\newline 0.9511-0.1604k_t+4.388k_t^2-16.638k_t^3+12.336k_t^4 & & 0.22 \leq k_t \leq 0.8\newline 0.165& & k_t > 0.8 \endcases

• Direct Normal Irradiance (\mjseqnDNI, W/m^2) \mjsdeqnDNI = \frac(1-k_d)\cos(zenith)\timesGHI

• Diffuse Horizontal Irradiance (\mjseqnDHI, W/m^2) \mjsdeqnDHI = k_d\timesGHI where:
  \mjseqnGHI - Global Horizontal Irradiance (\mjseqnGHI, W/m^2) from MERRA-2 dataset. \mjsdeqnGHI = DHI + DNI \times\cos(zenith)

Examples

NA

energyRt/merra2ools documentation built on May 2, 2024, 4:53 a.m.