Capacity Benefit Margin (CBM)
Effective: April 1, 2011
CBM is defined as the amount of firm transmission transfer capability set aside by a TSP for use by the Load Serving Entities. ISO-New England does not set aside any CBM for use by the Load Serving Entities because of the New England approach to capacity planning requirements in the ISO-New England Operating Documents. Load Serving Entities operating within the New England Control Area are required to arrange for their Capacity Requirements prior to the beginning of any given month in accordance with ISO Tariff, Section II.188.8.131.52 (Calculation of Capacity Requirements and Capacity Load Obligation). Load Serving Entities do not utilize CBM to ensure their capacity needs are met; therefore, CBM is not applicable within the New England market design. Accordingly, for purposes of ATC calculation, as long as this market design is in place in New England, the CBM is set to zero (0). VTransco provides local transmission service over its non-PTF facilities that are connected to ISO-NE and the Vermont distribution utilities. VTransco does not reserve CBM for these paths, and the CBM is presently set to zero.