Total Transmission System Load (TTSL)

TTSL is an approximation of loading on any part of the BPA transmission system, based on federal and non-federal generation within the BPA control area, and interchange and wheeling onto the system. It is unadjusted for temperature or streamflow conditions. The date and time of the monthly TTSL peak is used for billing purposes. TTSL is not used as a "system load" measure for any formal regulatory reporting. TTSL data are unavailable prior to 1/1/07. Source: RODS acct 272500.

  • Total Transmission System Load, Monthly Peaks 2007-2009
    Peak monthly values of TTSL occurred as follows. Customers should direct questions to their Account Executive (AE) or the central AE office at 360-619-6016.
    Jan-07: 1/15/07 HE9
    Feb-07: 2/1/07 HE8
    Mar-07: 3/28/07 HE8
    Apr-07: 4/19/07 HE8
    May-07: 5/29/07 HE15
    Jun-07: 6/28/07 HE14
    Jul-07: 7/10/07 HE16
    Aug-07: 8/29/07 HE17
    Sep-07: 9/4/07 HE21
    Oct-07: 10/25/07 HE20
    Nov-07: 11/26/07 HE19
    Dec-07: 12/26/07 HE19
    Jan-08: 1/21/08 HE19
    Feb-08: 2/13/08 HE19
    Mar-08: 3/3/08 HE19
    Apr-08: 4/1/08 HE8
    May-08: 5/19/08 HE17
    Jun-08: 6/30/08 HE13
    Jul-08: 7/9/08 HE17
    Aug-08: 8/14/08 HE17
    Sep-08: 9/8/08 HE17
    Oct-08: 10/16/08 HE20
    Nov-08: 11/24/08 HE19
    Dec-08: 12/16/08 HE8
    Jan-09: 1/27/09 HE20
    Feb-09: 2/9/09 HE19
    Mar-09: 3/11/09 HE8
    Apr-09: 4/22/09 HE21
    May-09: 5/18/09 HE17
    Jun-09: 6/24/09 HE16
    Jul-09: 7/27/09 HE17
    Aug-09: 8/19/09 HE17
    Sep-09: 9/2/09 HE16
    Oct-09: 10/13/09 HE20
    (Last update, 11/2/09)
  • Total Transmission System Load, Rolling 60-Day Report
    Data and plot of TTSL by hour over the last 60 days, including date, time,
    and amount of peak for current month and prior month. Updated daily.
  • Total Transmission System Load, Hourly Data, 2007
  • Total Transmission System Load, Hourly Data, 2008
  • Total Transmission System Load, Hourly Data, 2009