Jump to content

wind rose spoke shading: total wind energy vs. total time

Robert Peplin

Recommended Posts

 I'm gaining a better understanding of NRG's wind rose and how to interpret the data (e.g. TI, Outer Circle %).  What I'd like to have explained is the division of each compass sector between "Percent of Total Wind Energy" and "Percent of Total Time." This was instigated by a recent wind rose I printed where the southern direction had only a "checkered" spoke (about 15%) but nothing "solid". This made me ask "how can there be wind coming from the south for a significant amount of time and yet no 'wind energy?'"

Does the wind vane work in combination with the anemometer and through the SDR software calculate wind energy?  So, with my above example, if the vane was pointing south for a decent amount of time but with very low winds, would this explain why "total time" was shown on the rose but not "total wind energy"?  I assume then this would also apply to converse situations where total wind energy spokes exceed total time spokes?  Lots of wind energy but not over a long period (gusts?).  Last, if my assumption is correct with the anemometer interplay, what is the lower threshold for which wind speed data are used?  Is it the 4.5 m/s stated on the wind rose print-put?  Thanks for the help!

Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...