such an analysis. Since marginal emissions are generally lower than average emissions and marginal emissions reflect the impact on air quality, these emissions are generally of greatest interest.
Marginal emissions are affected by local air quality regulations, permit requirements for new facilities, permits for existing power generation capacity, the source of feedstocks, and economic forces. Ideally, a fuel-cycle analysis would reflect the interaction of regulatory, economic, and supply considerations. An important parameter is the total volume of fuel that is sold. When evaluating the effect of using an alternative fuel, the implicit assumption is that the alternative displaces gasoline. Such a displacement would require a one-for-one economic elasticity. However, if alternative fuels captured market share, through economic or regulatory forces, additional gasoline would be available for sale. The effect of alternative fuel use in California could achieve the following effects:
Displace gasoline sales
Provide additional gasoline which could reduce the price of gasoline and stimulate demand
Increase the supply of oil and put pressure on oil prices
Such price-elasticity issues have a more significant effect on global fuel production. In California, fuel demand is fairly inelastic and stationary emissions are largely driven by regulatory considerations.
Emissions for marginal alternative fuel production and gasoline displacement were calculated for fuel-cycle activities in the SoCAB. The marginal emission values were estimated adjusted according to Table 3-4. The net result of the marginal analysis is that NOx emissions amount only to tanker ship and truck emissions in the SoCAB. All other NOx emissions are either controlled by RECLAIM or are associated with fuel production out side of the SoCAB. NMOG emissions correspond to fuel storage and distribution activities as well as power production for EVs.
Table 3-4: Adjustments for Marginal Fuel-Cycle Emission Analysis in the SoCAB, 2010
Marginal Analysis Assumptions
Zero emissions for phase 3.
Reformulated diesel, LPG
Same as diesel. Add emissions associated with additional refinery energy use (mostly electric power).
Methanol from natural gas, biomass
Produced outside of the South Coast. Phases 1 through 4 do not result in SoCAB emissions.
Methanol from LFG
Credit for reducing NMOG emissions from flaring or power generation. No NOx credit for eliminating IC engine.
Natural gas for refineries
Zero emissions except for pipeline transmission emissions in phase 5. Emissions assosciated with pipeline leakage do not increase with increased throughput.