Eastern, WECC, ERCOT and Hydro Quebec

August, 2012 Frequency Events’ Data Summary and

Corresponding Frequency Plots

For: NERC Resources Subcommittee and Frequency Working Group

Prepare by: CERTS and Electric Power Group

Date: September 26, 2012

NERC INTERCONNECTIONS AUGUST, 2012 FREQUENCY EVENTS – SUMMARY DATAEASTERN

WESTERN

ERCOT

HYDRO QUEBEC

Frequency Response can be calculated from NERC SA Actual MW Loss divided by 10* B-A. The results will be in MW/0.1 HZ

9/27/2012

1

EASTERN INTERCONNECTION

AUGUST, 2012 FREQUENCY EVENTS

9/27/2012

2

WESTERN INTERCONNECTION

AUGUST, 2012 FREQUENCY EVENTS

9/27/2012

3

ERCOT INTERCONNECTION

AUGUST, 2012 FREQUENCY EVENTS

9/27/2012

4

HQ INTERCONNECTION

AUGUST, 2012 FREQUENCY EVENTS

9/27/2012

5

9/27/2012

6

9/27/2012

7

9/27/2012

8

9/27/2012

9