Wind Energy Production in China over the past 10 years (Graphic at bottom)

library(tidyverse)
library(grid)
#library(devtools)
#install_github('alex-stephenson/geomwindmill')  #available on my GitHub
library(geomwindmill) #package for customised function to make windmill shaped bars in barplot
library(hrbrthemes)
import_plex_sans()

data <- read_csv('Global_elec_review_2020_China.csv')

data_clean <- data %>%
  filter(Category %in% c('Fossil generation', 'Fossil-free generation')) %>% 
  filter(Type == "Wind") %>% 
  select(Type, Year, Value_TWh) %>% 
  filter(Year >= 2010) %>% 
  mutate(id = seq(1,10)) %>% 
  mutate(film_year = paste("   ", Year,":", Value_TWh, "TWh    "))
  
label_data <- data_clean
number_of_bar <- nrow(label_data)
angle <-  90 - 360 * (label_data$id-0.5) /number_of_bar 
label_data$hjust<-ifelse( angle < -90, 1, 0)
label_data$angle<-ifelse(angle < -90, angle+180, angle)

ggplot(data_clean, aes(x=Year, y=Value_TWh, color=id, group = id)) +
  geom_windmill(color='black', aes(fill=Value_TWh), span_x = 0.9) + #code for this function is available on my GitHub
  coord_polar() +
  ylim(-150,500)  + 
   geom_rect(xmin = 2014.39, xmax = 2014.6, ymin = 200, ymax = 600,
            alpha = 1, fill = "darkgrey", colour = "black") +
  theme_minimal() +
  geom_text(aes(label=film_year),
                  hjust = label_data$hjust,
                  color = "black",
                  fontface = "bold",
                  alpha = 0.6,
                  size = 3.6,
                  angle = label_data$angle) + 
                  coord_polar(start = 0) +
    labs(title = "\nBlowing in the Wind:\nThe Growth of Wind Energy\nProduction in China", subtitle = "Between the years 2010 and 2020", caption = "Data: Ember Global Electricity Review\n Graphics: Alex Stephenson (generated using R)") +
  theme( axis.text = element_blank(),
               axis.title = element_blank(),
                plot.background = element_rect(fill = "lightgreen", color = NA),
               plot.title = element_text(size = 26, face = "bold", colour = '#2F4F4F', hjust = 1),
              plot.subtitle = element_text(size = 16, face = c("bold.italic"), hjust = 1, colour = '#2F4F4F'),
               panel.grid = element_blank(), 
              plot.caption = element_text(face = "bold.italic", size = 16, hjust = 1),
              legend.position = "none")

## Coordinate system already present. Adding new coordinate system, which will replace the existing one.