(a) Calculate the annual SF6 and PFC emissions using the mass-balance approach in Equation DD-1 of this section:
where:
Decrease in SF6 Inventory = (pounds of SF6 stored in containers, but not in energized equipment, at the beginning of the year) − (pounds of SF6 stored in containers, but not in energized equipment, at the end of the year).
Acquisitions of SF6 = (pounds of SF6 purchased from chemical producers or distributors in bulk) + (pounds of SF6 purchased from equipment manufacturers or distributors with or inside equipment, including hermetically sealed-pressure switchgear) + (pounds of SF6 returned to facility after off-site recycling).
Disbursements of SF6 = (pounds of SF6 in bulk and contained in equipment that is sold to other entities) + (pounds of SF6 returned to suppliers) + (pounds of SF6 sent off site for recycling) + (pounds of SF6 sent off-site for destruction).
Net Increase in Total Nameplate Capacity of Equipment Operated = (The Nameplate Capacity of new equipment in pounds, including hermetically sealed-pressure switchgear) − (Nameplate Capacity of retiring equipment in pounds, including hermetically sealed-pressure switchgear). (Note that Nameplate Capacity refers to the full and proper charge of equipment rather than to the actual charge, which may reflect leakage).
(b) Use Equation DD-1 of this section to estimate emissions of PFCs from power transformers, substituting the relevant PFC(s) for SF6 in the equation.