windfarmGA (version 2.3.0)

calculate_energy: Calculate Energy Outputs of Individuals

Description

Calculate the energy output and efficiency rates of an individual in the current population under all given wind directions and speeds. If the terrain effect model is activated, the main calculations to model those effects will be done in this function.

Usage

calculate_energy(
  sel,
  referenceHeight,
  RotorHeight,
  SurfaceRoughness,
  wnkl,
  distanz,
  polygon1,
  resol,
  RotorR,
  dirSpeed,
  srtm_crop,
  topograp,
  cclRaster,
  weibull,
  plotit = FALSE
)

Arguments

sel

A data.frame of an individual of the current population (data.frame)

referenceHeight

The height at which the incoming wind speeds were measured (numeric)

RotorHeight

The desired height of the turbines

SurfaceRoughness

A surface roughness length of the considered area in m. If the terrain effect model is activated, a surface roughness will be calculated for every grid cell with the elevation and land cover information

wnkl

Indicates the angle at which no wake influences are considered (numeric)

distanz

Indicates the distance after which the wake effects are considered to be eliminated

polygon1

The considered area as shapefile

resol

The resolution of the grid in meter

RotorR

The desired rotor radius in meter

dirSpeed

The wind speed and direction data.frame

srtm_crop

A list of 3 raster, with 1) the elevation, 2) an orographic and 3) a terrain raster. Calculated in genetic_algorithm

topograp

Logical value that indicates whether the terrain effect model is activated (TRUE) or deactivated (FALSE)

cclRaster

A Corine Land Cover raster that has to be downloaded previously. See also the details at windfarmGA The raster will only be used when the terrain effect model is activated. (raster)

weibull

A raster representing the estimated wind speeds

plotit

Logical value. If TRUE, the process will be plotted. Default is FALSE.

Value

Returns a list of an individual of the current generation with resulting wake effects, energy outputs, efficiency rates for every wind direction. The length of the list will be the amount of incoming wind directions.

See Also

Other Wind Energy Calculation Functions: barometric_height(), get_dist_angles(), turbine_influences()

Examples

# NOT RUN {
## Create a random shapefile
library(sp)
Polygon1 <- Polygon(rbind(c(4498482, 2668272), c(4498482, 2669343),
                    c(4499991, 2669343), c(4499991, 2668272)))
Polygon1 <- Polygons(list(Polygon1),1);
Polygon1 <- SpatialPolygons(list(Polygon1))
Projection <- "+init=epsg:3035"
proj4string(Polygon1) <- CRS(Projection)

## Create a uniform and unidirectional wind data.frame and plot the
## resulting wind rose
data.in <- data.frame(ws = 12, wd = 0)
windrosePlot <- plot_windrose(data = data.in, spd = data.in$ws,
                dir = data.in$wd, dirres=10, spdmax=20)

## Assign the rotor radius and a factor of the radius for grid spacing.
Rotor= 50; fcrR= 3
resGrid <- grid_area(shape = Polygon1, resol = Rotor*fcrR, prop=1,
                      plotGrid = TRUE)
## Assign the indexed data frame to new variable. Element 2 of the list
## is the grid, saved as SpatialPolygon.
resGrid1 <- resGrid[[1]]

## Create an initial population with the indexed Grid, 15 turbines and
## 100 individuals.
initpop <- init_population(Grid = resGrid1, n = 15, nStart = 100)

## Calculate the expected energy output of the first individual of the
## population.
par(mfrow = c(1,2))
plot(Polygon1); points(initpop[[1]][,'X'],initpop[[1]][,'Y'], pch=20,cex=2)
plot(resGrid[[2]], add = TRUE)
resCalcEn <- calculate_energy(sel=initpop[[1]],referenceHeight= 50,
                   RotorHeight= 50, SurfaceRoughness = 0.14,wnkl = 20,
                   distanz = 100000, resol = 200,dirSpeed = data.in,
                   RotorR = 50, polygon1 = Polygon1, topograp = FALSE,
                   weibull = FALSE)
resCalcEn <- as.data.frame(resCalcEn)
plot(Polygon1, main = resCalcEn[,'Energy_Output_Red'][[1]])
points(x = resCalcEn[,'Bx'], y = resCalcEn[,'By'], pch = 20)


## Create a variable and multidirectional wind data.frame and plot the
## resulting wind rose
data.in10 <- data.frame(ws = runif(10,1,25), wd = runif(10,0,360))
windrosePlot <- plot_windrose(data = data.in10, spd = data.in10$ws,
                dir = data.in10$wd, dirres=10, spdmax=20)

## Calculate the energy outputs for the first individual with more than one
## wind direction.
resCalcEn <- calculate_energy(sel=initpop[[1]],referenceHeight= 50,
                   RotorHeight= 50, SurfaceRoughness = 0.14,wnkl = 20,
                   distanz = 100000, resol = 200,dirSpeed = data.in10,
                   RotorR = 50, polygon1 = Polygon1, topograp = FALSE,
                   weibull = FALSE)
# }
# NOT RUN {
# }