Cumulative Imbalances

  • A Cumulative Imbalance for a noncore customer is the difference between actual usage (plus adjustments and carryovers) and actual deliveries (plus shrinkage)
  • A Cumulative Imbalance for a Core Procurement Group* is the difference between actual calendar month gas deliveries and the sum of each day's "modified determined usage" for that same calendar month. The modified determined usage is:
    • a day-after the gas day usage estimated by Pacific Gas and Electric Company (determined usage)
    • plus the amount of the Operating Imbalance Carryover Account (generally 1/12 of the Carryover Account balance) applied to the month's supply.
    • plus any accounting adjustments, divided by the number of days within the month
  • Cumulative Imbalances may be traded:
    • with other Cumulative Imbalances from the same calendar month, and/or
    • into or out of storage
    • with tradeable Operating Imbalances
  • The imbalance tolerance band is 5% of metered or determined usage
  • Cumulative Imbalance statements will be sent during the month after the delivery month

Trading Imbalances

  • Imbalance trading occurs during the second half of the month after the delivery month
  • Customers can trade Cumulative Imbalances past zero, subject to a 3% limit
  • Each Cumulative Imbalance trade must meet one of the following criteria:
    • the trade moves the imbalance towards zero
    • the trade results in an ending imbalance within +/- 3% of metered or determined usage
  • Any remaining Cumulative Imbalance within the tolerance band will be carried forward to the following month's Cumulative Imbalance
  • Any Cumulative Imbalance in excess of the tolerance band will be cashed out as described in Cashout Components in the month after imbalance trading
  • The Cumulative Imbalance Cycle gives more details regarding date ranges for these different phases in the process
    Managing Cumulative Imbalances

Managing Cumulative Imbalances

Noncore customers have three options for managing Cumulative Imbalances: manage their own imbalances, authorize a nominating market to trade imbalances or assign imbalances to a balancing agent. See Managing Cumulative Imbalances for further details.

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Core Procurement Groups include Pacific Gas and Electric Company's Core Procurement Department and Core Transport Groups as defined in Schedule C-GT.