FIGURE 4.21 GHG emissions for scenarios combining ICEV Efficiency Case, Biofuels Case, and PHEVs or HFCVs for the EPRI/NRDC grid mix.

FIGURE 4.21 GHG emissions for scenarios combining ICEV Efficiency Case, Biofuels Case, and PHEVs or HFCVs for the EPRI/NRDC grid mix.

higher-carbon EIA grid, the GHG reduction with PHEV-10s (PHEV-40s) is about 55 percent (59 percent), about the same as for efficiency + biofuels.

SCENARIO SUMMARY

Societal Benefits of PHEVs

  • GHG and oil reductions for PHEVs are small before 2025 because of the time needed for vehicles to penetrate the market.

  • PHEV GHG benefits depend on the grid mix:

    • PHEV benefits are small compared with HEVs for the EIA grid.

    • With a low-carbon grid (EPRI/NRDC mix), introduction of PHEV-40s could significantly lower GHG emissions relative to HEVs.

  • Increasing conventional vehicle efficiency alone (without PHEVs) can reduce oil use by about 40 percent in 2050 compared with the Reference Case. Adding PHEV-10s at the Maximum Practical rate can reduce oil use an additional 7 percent, while PHEV-40s can reduce it an additional 23 percent.

  • Implementing efficiency plus biofuels reduces gasoline use by about 65 percent compared with the Reference Case. Adding PHEV-10s at the Maximum Practical rate can reduce oil use an additional 7 percent, while PHEV-40s can reduce it 23 percent.

  • A portfolio approach incorporating efficiency, more use of HEVs and biofuels, as well as PHEVs, yields greater reductions in oil use and GHG.

  • Long-term GHG and oil-use reductions are greater with HFCVs than PHEVs for similar levels of energy supply decarbonization (NRC Hydrogen scenario; EPRI/NRDC grid). If PHEVs are charged from the EIA grid, GHG emission reductions with PHEVs will be much less than with HFCVs.

Transition Costs

  • Transition costs and timing to breakeven are similar for HFCVs and PHEV-10s, i.e., tens of billions of dollars total, spent over a 10-20 year period. This is less than the current corn ethanol subsidy of about $10 billion per year.

  • Majority of transition cost (more than 80 percent) is for vehicle buydown. Average price subsidy needed for HFCVs and PHEV-10s over a 10-15 year transition period is similar, about $5000 to $6000 per car for PHEV-10s, and $7,000 to $9,000 per car for HFCVs.

  • Transition costs for PHEV-40s are significantly higher than for PHEV-10s, because of higher vehicle first cost. Break-even year for the PHEV-40 is 2040 in the Optimistic Technology Case, but not until 2047 for the Probable Case, unless the oil price is high or the cost of batteries can be reduced rapidly.

  • Slower Probable Case transition strategies sometimes have a lower overall transition cost than the Maximum Practical Case. This is true because the Maximum Practical Case buys large numbers of expensive early PHEVs.

  • Transition costs are sensitive to oil prices and to vehicle cost increment, which depends on battery cost assumptions, but are not very sensitive to electricity price.

  • Infrastructure costs for PHEVs might average $1000 per car for residential charging.

  • Total infrastructure capital costs to breakeven are the same order of magnitude for PHEV-10s and HFCVs, although early infrastructure logistics are less complex with PHEVs.

Overall Messages from Scenarios

  • Bringing PHEVs to cost-competitiveness will take several decades and require many billions of dollars in support. Transition costs for PHEV-40s are significantly larger than for PHEV-10s, but the reduction in gasoline consumption is greater also.

  • GHG benefits of PHEVs depend on the grid mix. With a business-as-usual EIA grid mix, the benefits of PHEVs are similar to those for efficient gasoline HEVs. With a substantially decarbonized grid, PHEVs can save 4-16 percent more GHG emissions than efficient HEVs.

  • The PHEV transition cost and timing results are sensitive to the oil price and the battery cost. But even with relatively high oil prices (AEO high oil price case $80-$120 per barrel) and achievement of aggressive battery goals (similar to the DOE goals), it will take 15-20 years and tens to hundreds of billions of dollars to bring PHEV-40s to commercial success.



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