Load Growth Update


Ansergy computes load growth daily; we use the output in both our near term (5 years) and long-term (20-30 year) forecasts. The results are always exciting and we’d like to share those with you today.



Ansergy forecasts WECC loads at a Balancing Authority level. The Load Growth model matches same degree days across years. A match occurs whenever the degree days are within an allowed tolerance and the days must match by Day of Week, Hour, and Business Day.  Tolerance is the absolute value of degree day delta between the two years; the model accepts only those matches that fall within the tolerance.

The field “Tests” returns the number of matches found within the tolerance.  Prior Year is the average of demand for all of those tests for all test years. Current Year is the most recent year. The delta is Current – Prior and the Load Growth % is Delta divided by Prior Year.  A filter is applied at the test level to throw out unreasonable deltas. These occur during power outages, strikes, and other abnormal events.


WECC load growth is all over the map, but California appears to be growing faster than the WECC interior.

NOTE: Drop me a note or call if you would like to receive either the data from the study or further explore the methodologies.