How it works
The daily average usage of each core customer within a CAT group is used to determine an estimated calendar month usage for the CAT group. The portion of each accounts billing period that was projected for the part of the calendar month after the regular meter read date is trued up during the subsequent month.
The "true up" is based on the meter's actual daily average usage in that month's billing period compared to the average daily usage from the prior month.
Automatic Meter Reading
Noncore self-procurement customers have automatic meter reading (AMR) devices installed that allow SDG&E to obtain the customers' actual daily usage (midnight to midnight).
The billing period for all self-procurement, noncore customers is based on the calendar month (12:00 AM meter read of the 1st day of the month through the 12:00 AM meter read of the first day of the subsequent month).
Throughout the calendar month, the customer's daily usage is posted in a file on SoCalGas's GasSelect website.
Noncore self-procurement customers with a meter(s) which is billing on a core rate and located on the same premise as the noncore meter, may also self-procure the core load in aggregate with their noncore load. Core meters do not have AMR.
By the 20th of the following month, noncore self-procurement customers and/or their authorized GSP, and Core Aggregation Transportation (CAT) agents will receive an imbalance notice which officially identifies the amount of gas consumed compared to the amount of gas actually delivered delivered adjusted for any allowable carry-over from prior month and any mandatory core reliability storage injections.
The net difference is the imbalance. If the imbalance is greater than or less than 10% of the customer's usage, the excess must be traded in order to avoid imbalance charges associated with Schedule G-IMB.
Imbalance trading period
SDG&E's imbalance trading period matches the SoCalGas imbalance trading period as defined in Schedule G-IMB:
Trading period will be in the month following the month imbalance was created.
Trading period will open on the 25th of the month and close at midnight on the 30th of the month (including holidays and weekends). Exception will be the month of February; Opens on the 23rd of the month and closed at midnight on 28th (including holidays and weekends).
If you are a Gas Service Provider
GSPs should access their noncore customer's daily consumption on GasSelect frequently during the month to determine if an adjustment to their nominated daily delivered volume is necessary in order to stay within the Schedule G-IMB balancing tolerances.
For additional information regarding gas balancing contact: