Title 40
SECTION 89.207
89.207 Credit calculation.
§ 89.207 Credit calculation.(a) Requirements for calculating NOX credits from Tier 1 engines rated at or above 37 kW. (1) For each participating engine family, emission credits (positive or negative) are to be calculated according to one of the following equations and rounded, in accordance with ASTM E29-93a, to the nearest one-hundredth of a megagram (Mg). This ASTM procedure has been incorporated by reference (see § 89.6). Consistent units are to be used throughout the equation.
(i) For determining credit availability from all engine families generating credits: Emission credits = (Std−FEL) × (Volume) × (AvgPR) × (UL) × (Adjustment) × (10−6)
(ii) For determining credit usage for all engine families requiring credits to offset emissions in excess of the standard:
Emission credits = (Std−FEL) × (Volume) × (AvgPR) × (UL) × (10−6) Where: Std = the applicable Tier 1 NOX nonroad engine emission standard, in grams per kilowatt-hour. FEL = the NOX family emission limit for the engine family in grams per kilowatt-hour. Volume = the number of nonroad engines eligible to participate in the averaging, banking, and trading program within the given engine family during the model year. Engines sold to equipment or vehicle manufacturers under the provisions of § 89.102(g) shall not be included in this number. Quarterly production projections are used for initial certification. Actual applicable production/sales volume is used for end-of-year compliance determination. AvgPR = the average power rating of all of the configurations within an engine family, calculated on a sales-weighted basis, in kilowatts. UL = the useful life for the engine family, in hours. Adjustment = a one-time adjustment, as specified in paragraph (a)(2) of this section, to be applied to Tier 1 NOX credits to be banked or traded for determining compliance with the Tier 1 NOX standards or Tier 2 NOX + NMHC standards specified in subpart B of this part. Banked credits traded in a subsequent model year will not be subject to an additional adjustment. Banked credits used in a subsequent model year's averaging program will not have the adjustment restored.(2) If an engine family is certified to a NOX FEL of 8.0 g/kW-hr or less, an Adjustment value of 1.0 shall be used in the credit generation calculation described in paragraph (a)(1)(i) of this section. If an engine family is certified to a NOX FEL above 8.0 g/kW-hr, an Adjustment value of 0.65 shall be used in the credit generation calculation described in paragraph (a)(1)(i) of this section. If the credits are to be used by the credit-generating manufacturer for averaging purposes in the same model year in which they are generated, an Adjustment value of 1.0 shall be used for all engines regardless of the level of the NOX FEL. If the credits are to be banked by the credit-generating manufacturer and used in a subsequent model year for another Tier 1 engine family, an Adjustment value of 1.0 shall be used for all engines regardless of the level of the NOX FEL.
(b) Requirements for calculating NMHC + NOX Credits from Tier 2 and later engines rated at or above 37 kW and Tier 1 and later engines rated under 37 kW and PM credits from all engines. (1) For each participating engine family, NOX + NMHC emission credits and PM emission credits (positive or negative) are to be calculated according to one of the following equations and rounded, in accordance with ASTM E29-93a, to the nearest one-hundredth of a megagram (Mg). This procedure has been incorporated by reference (see § 89.6). Consistent units are to be used throughout the equation.
(i) For determining credit availability from all engine families generating credits:
Emission credits = (Std-FEL) × (Volume) × (AvgPR) × (UL) × (10−6)(ii) For determining credit usage for all engine families requiring credits to offset emissions in excess of the standard:
Emission credits = (Std-FEL) × (Volume) × (AvgPR) × (UL) × (10−6) Where: Std = the current and applicable nonroad engine emission standard, in grams per kilowatt-hour, except for PM calculations where it is the applicable nonroad engine Tier 2 PM emission standard, and except for engines rated under 19 kW where it is the applicable nonroad engine Tier 2 emission standard, in grams per kilowatt-hour. (Engines rated under 19 kW participating in the averaging and banking program provisions of § 89.203(c)(3)(ii) shall use the Tier 1 standard for credit calculations.) FEL = the family emission limit for the engine family in grams per kilowatt-hour. Volume = the number of nonroad engines eligible to participate in the averaging, banking, and trading program within the given engine family during the model year. Engines sold to equipment or vehicle manufacturers under the provisions of § 89.102(g) shall not be included in this number. Quarterly production projections are used for initial certification. Actual applicable production/sales volume is used for end-of-year compliance determination. AvgPR = the average power rating of all of the configurations within an engine family, calculated on a sales-weighted basis, in kilowatts. UL = the useful life for the given engine family, in hours. [63 FR 57008, Oct. 23, 1998]