CONCLUSIONS AND POLICY RECOMMENDATIONS
Even though California has made much progress in improving its air quality over the last 30 years, many parts of the state still violate federal ozone standards. The South Coast Air Basin is far short of the emission reductions required to meet these standards. This shortfall motivates CARB's goal of a zero emission fleet and its first step toward this goal, the ZEV program.
This report examines the costs of and the emission reductions from the various vehicle technologies that manufacturers may use to meet ZEV program requirements. In this concluding section, we summarize our key findings, discuss the conclusions we draw from them, and arrive at implications for ZEV policy.
We examined the cost of requiring vehicles to meet progressively tighter emission standards per ton of emissions reduced. We restricted our attention to reductions in non-methane organic gas (NMOG) and oxides of nitrogen (NOx) emissions, which are the key pollutants that must be reduced if California is to meet air quality standards. We examined the cost per ton of moving from CARB's tightest standards outside the ZEV program (the super low emission vehicle [SULEV] exhaust standard and the near-zero evaporative emission standard) to partial zero emission vehicles (PZEVs) and then from PZEVs to ZEVs. We also examined the cost per ton of moving from PZEVs to gasoline electric hybrid vehicles (GHEVs), vehicles that must meet PZEV exhaust and evaporative emission standards but that produce fewer indirect emissions (from fuel extraction, refining, and distribution) than PZEVs do because of their greater fuel efficiency.
We examined costs during the first five years of the program (2003 through 2007) and when the vehicles are in high-volume production. The high-volume cost estimates are based on designs that appear feasible given what is known about battery and fuel-cell technology. They also take into account the types of production processes that are feasible at high volume. Forecasting technological advances is difficult and becomes more so the farther one looks into the future. We thus think it appropriate to interpret our high-volume estimates as the lowest level to which costs are expected to fall over the next 10 years or so given what is currently known about advanced vehicle technologies and manufacturing processes. As manufacturers gain production experience, costs may drop beyond our volume production predictions, but we do not expect these effects to be large over the next 10 years absent significant technological advances. We