ERCOT Files Reserve Margin Report

ERCOT has filed a report on simulations used to identify target reserve margin levels (Planning Reserve Margin) at which specific physical reliability standards would be satisfied

The report concludes that if the target reserve margin were based on the metrics of 2.4 hours per year or 0.001% normalized EUE (Expected Unserved Energy), the resulting reserve margins would be 12.0% or 11.5%, respectively.

The 1-day-in-l0-year standard (0.1 LOLE, Loss of Load Expectation) results in a 16.75% target reserve margin for the ERCOT region

If the impact of load forecast error is removed, the target reserve margins which achieve the specified reliability standards shift down by approximately 1.25%.

Base case results for each reserve margin studied were as follows:

                                            Normalized
Reserve     LOLE        LOLH      EUE          EUE
Margin   Events Per   Hours Per   MWh       EUE (MWh)/
  %         Year        Year             Total Load (MWh)
7.6%        4.07       14.33    21,563       0.0062%
9.7%        2.00        6.57     8,569       0.0025%
11.9%       0.88        2.68     3,041       0.0009%
13.0%       0.55        1.61     1,653       0.0005%
14.2%       0.33        0.95       895       0.0003%
15.3%       0.20        0.55       493       0.0001%
16.5%       0.12        0.32       241       0.0001%
17.7%       0.06        0.17       123       0.0000%
18.9%       0.03        0.09        53       0.0000%
21.5%       0.01        0.02        13       0.0000%
24.2%       0.00        0.01         4       0.0000%

See ERCOT's full report in Project 42302 (click here)