Published on March 6th, 2016 | by Joshua S Hill19
Researchers Discover Predictability Of Unpredictable Wind Energy
March 6th, 2016 by Joshua S Hill
New research has found that, contrary to popular belief, geographically separated wind farms are acting in surprisingly similar ways.
A team of researchers, led by Professor Mahesh M. Bandi of the Okinawa Institute of Science and Technology Graduate University (OIST), published findings in the journal New Journal of Physics, revealing that, counter to what was previously thought, wind farms connected to the grid saw power outputs fluctuate in similar ways.
“It’s generally assumed that geographically distributed wind farms are independent,” Bandi said. “In other words, the fluctuations in power output from one wind farm are different from that of another wind farm, say 50 km away.” However, the data that Bandi and his team analysed, based on Irish wind farms connected to the local grid, revealed that wind farms did not function separately to one another, but rather “became part of a larger geographic weather system that forces all the wind farms to have similar or correlated outputs for a time span of up to one day.”
“If there is a medium that connects them, then one will observe that the two wind farms will fluctuate in a similar fashion,” Bandi continued. “This does not mean their outputs are exactly synchronized at every instant, but on average their outputs fluctuate very similar to each other. The average is important. That is what we mean by correlated.”
The results of their analysis allowed the researchers to quantify two types of forecast error: a timescale error “that quantifies the timescales over which the forecast models fail to predict high frequency power fluctuations,” and a scaling error, “that establishes a difference in the self-similar scaling of fluctuations as observed for actual generated power vis à vis the power that was forecast to be generated.”
If all of this seems a little vague, the full report is available for free to read on the New Journal of Physics website, and provides more context for the two errors that were the focus of the report.