The Science Behind Cascading Power Failures

Cascading power failures are the result of a domino effect where a vulnerable part of the grid creates additional downstream outages.  And a new study found that just a few vulnerable areas of the U.S. power grid are responsible for most of the country’s large-scale power outages through this cascading effect.

The Numbers Behind Cascading Power Failures

The research study, conducted by scientists at Northwestern University, analyzed 5-years’ worth of recent transmission line data to look for a “primary failures,” which represent the type of outage that could trigger a cascading effect.  The analysis revealed that about 85% of all primary failures occurred at approximately 20% of the grid.  These weak links tend to be geographically clustered near highly-populated areas, amplifying the effect.

The bottom line is that country-wide, the percentage of power lines susceptible to a primary failure is very small, yet this small percentage tends to cause a disproportionately large percentage of overall power failures.  What this means is that these areas should be top priority for power line upgrades.  One scientist called this a “failure-based resource allocation” approach and it makes sense to me.

Targeting areas of the grid that trigger cascading power failures for upgrades is a great way to facilitate overall emergency preparedness.  It will be interesting to monitor this going forward to see if these weak links are indeed targeted for upgrades.  I, for one, hope the answer is a resounding “yes”!