California's Zero Emission Vehicle (ZEV) Program

California's Zero Emission Vehicle (ZEV) regulation has evolved since it was first enacted in 1990. Today's regulation provides a balance between advancing future technology and getting near-term advanced vehicles, such as hybrids, on the road. The regulation required that automakers provide a certain percentage of different types of zero emission vehicles for sale or in demonstration programs in California: 11 percent of their total vehicle sales in California for the phase between 2009 and 2011, increased to 12 percent for the phase between 2012 and 2014.

Through a complex credit system, the manufacturers are given a considerable amount of flexibility in the number and type of vehicles they produce. Yet, many auto companies have opted for the Alternative Path which allows them to fulfill their Gold Vehicle requirement with significantly fewer fuel cell vehicles. The table below shows the combined number of vehicles of each type which all six auto companies must produce in California over each three year period:  


 Phase II

 Phase III

Number of pure electric vehicles
(battery-electric, hydrogen fuel cell, etc.)



Number of plug-in hybrid vehicles



Number of conventional hybrid vehicles

 > 150,000


Number of ultra-clean gasoline vehicles

> 1 million 

> 1 million

*The plug-in hybrid category does not go into effect until 2012. Before that time, automakers can still receive credits for producing PHEVs under the conventional hybrid classification.

In addition, ten other states have adopted the same ZEV regulation which starting in 2012 more than doubles the number of ZEV vehicles on the road! This means that the ZEV regulations will place millions of advanced, clean vehicles on the road across the country.   

Because of the ZEV regulation, auto companies have put many different types of electric, fuel cell, and hybrid vehicles on the road. For example, the ZEV regulation is one reason why you can purchase a hybrid vehicle at a dealership today.

Today, a few hundred prototype fuel cell vehicles are being driven in demonstration programs and using the 25 hydrogen fueling stations across the state. You can even find some of the battery electric vehicles from the 1990s on the road today.

Still not enough choices? In addition to all-electric and hybrid vehicles, over forty different models of ultra-clean gasoline vehicles (PZEVs) are reducing significant amounts of smog forming pollution from the tailpipes of cars today.  

The ZEV Regulation Today—Success or Failure?
Despite the  controversy that surrounds the ZEV Program, it has improved air quality and introduced millions of drivers to hybrid and gasoline PZEV. The regulation has also helped to spur technological advancements in the electric motors, batteries, and vehicle design used in the hybrid and other advanced vehicles on the road today. Any changes to the program must continue to reduce smog and global warming pollution necessary to meet the long term air quality and greenhouse gas emission goals of California.

What's Next?
The California Air Resources Board (CARB) has ordered their staff to review the ZEV regulations and to return by the end of 2009 with a plan to overhaul them.  The staff will be required to take into account California's long term global warming goals which may mean large numbers of plug-in hybrids, battery electric, and fuel cell vehicles beginning in 2015.  In 2009, UCS will be creating a report that shows a path to reducing global warming emissions through 2050 using hundred of thousands, if not millions of zero emission vehicles. 

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