UCAP Peak Contribution is allocated to Participants based on the contribution to the previous calendar year's peak. Manual 20 Attachment C.4 states: To account for this Load-shifting, ISO-NE will conduct a financial true-up of the UCAP Obligation.  Using the daily data submissions by the Host Participants, ISO-NE tracks the shifts in UCAP responsibility throughout the month.

It is the Power Year. A UCAP Peak Contribution is subject to adjustments for load response, and exempted loads. Manual 20 Attachment C.1 offers: The peak used to determine UCAP Peak Contributions for daily submittal is the system-wide annual coincident peak from the previous calendar year.  Customer UCAP Peak Contributions are determined prior to the annual change in the Power Year on June 1. Power Year = June 1 through May 31
Summer Capability Period = June 1 through Sept 30
Winter Capability Period = October 1 through May 31

ISO-NE will notify all Participants of the NEPOOL UCAP Peak Contribution amount, as well as the peak date and time, via a Special Notice prior to the start of the new Power Year.