ok so this is a ggplot2 graphic but I don't see the code for this plot in the shiny code you put in your question.
Do I miss something ? Did you try to put the code for this app into the shiny app ?
Currently, your selectInput are selecting value from the power_draw_watt column of the data.frame, and you are trying to plot input$result that does not exist. Are you sure about the shiny code ?
See Shiny debugging and reprex guide