Road To Zero Emissions

Years of attempting to change driving and purchasing behavior have made regulators realize that the only way to attack the clean air problem is through technology.

Zero emissions from vehicles has been the mantra preached by regulators and environmentalists as the only hope for digging out from the nation's clean air problems. However, for car makers it has been a symbol of over-regulation, forcing them to market vehicles that they claim are too expensive and do not provide the performance characteristics demanded by the motoring public.

In the debate over zero emission vehicles, environmentalists point to surveys showing public desire for clean air. However, in terms of actual purchasing and driving practices, car owners have demonstrated that Americans' love affair with automobiles is not over, and that the sacrifices car owners are willing to make for clean air are extremely limited. Americans want to have their cake and eat it too. Government programs to encourage car pooling, emissions inspection, and mass transportation have had limited success in major cities.

This places the nation's clean air problem squarely on the doorstep of vehicle manufacturers. So far, their record has been astounding, substantially reducing emissions from cars. However, these gains seem to fuel regulator desires for lower emissions, pushing car companies to squeeze additional reductions to the point of zero.

Ten Percent by 2003?

The major push for zero emissions comes from California, which, until Houston took the lead in 2000, had the nation's most polluted city, Los Angeles. Earlier in the '90s, the California Air Resources Board (CARB), the group established to attack the state's extensive clean air problems, enacted a stringent mandate for zero emission vehicles. The mandate pushed car companies to produce 10 percent of their fleet with zero emissions vehicles (ZEV) by 2003. Further, car companies were to have two percent of their fleets electrically powered by 1998 and five percent by 2002. CARB knew it was shooting high, but it agreed to monitor the progress of technology and modify the requirements if necessary.

In fact, a CARB assessment conducted in 1996 conceded that battery technology and cost issues would prevent car companies from meeting the demanding rollout schedule. With limited driving ranges and high battery costs, it was unlikely motorists were going to flock to dealerships for electric vehicles. CARB decided to eliminate the interim deadlines, but retain the overall target of 10 percent by 2003.

In 1998 CARB relented to car company pressure once again, voting to provide additional flexibility in meeting the electric vehicle mandate. Specifically, car companies would be permitted the ability to meet six percent of their ZEV mandate with the production of super low emitting vehicles (SULEV). However, these vehicles would need to meet an extremely stringent emissions standard, as well as come with a 15 year/150,000 mile emissions warranty. If the vehicle producers took full advantage of this option, only four percent of their fleet would have to be pure zero emission vehicles.

The Road Blocks

The manufacturers continue to maintain that many of the same issues that they faced back in 1996 regarding cost and driving range limitations of battery technology are still true in 2000. This bleak assessment is shared by an Advisory Panel established by CARB to determine the status of battery technology. The report delivered to CARB earlier this year found many good technologies, but conceded that "major advances or breakthroughs would be required to reduce advanced battery costs substantially below current projections." The panel considered such advances unlikely for the next six to eight years.

Specifically, the panel found that nickel-metal hydride (NiMH) batteries demonstrated the ability to meet the power and endurance requirements for powering electric vehicles. However, it is not expected that the range would increase beyond 75 to 100 miles on a single charge, thus severely limiting its acceptability to a large number of car owners. The cost of these batteries, despite significant attempts at commercialization, are still very high. NiMH batteries cost between $9,500 and $13,000 each if produced in quantities of 10,000-20,000.

The panel also found lithium-ion batteries show promise, proving to be both reliable and safe. However, test data indicated that battery operating life was a disappointing two to four years. Further, the panel observed that lithium-ion batteries exhibit various degrees of sensitivity when subject to some of the abuse tests intended to simulate battery behavior and safety under high mechanical, thermal and electrical stresses. Resolution of these issues could take seven years, the panel said, and still these batteries will probably be more expensive than the NiMH batteries.

The bottom line, according to the panel, is that the practical range provided by the batteries of current electric vehicles is limited. "For applications where increased range is desired, the resulting larger-capacity batteries would aggravate the advanced-battery cost problem in proportion, and they would raise increasingly serious volume and weight issues," the panel's report said.

Sales Are Hardly Electric

In the current debate over zero emissions in California, the car companies have been pointing to the panel report as confirmation of what they have been saying for some years: due to cost and range issues, electric vehicles have only limited sales potential. In fact, in terms of actual sales, the electric vehicle has been a dud.

Honda recently discontinued production of the EV Plus with sales of only 297 vehicles. Toyota has sold only 507 of its RAV4-EV cars, and GM has sold only 660 of its electric vehicle, the EV1. Vehicle producers maintain that they will produce electric vehicles if forced to by regulators. However, outside of the ZEV mandate, consumer interest appears to be limited to small targeted markets where range is not a factor.

Hybrid Negotiations

CARB does not appear to be completely backing away from the zero emissions goal. While more concessions to the car companies may be forthcoming, CARB is pushing the car company engineers to figure out how to solve the paradox of keeping customers happy and meeting the zero emission goal. One compromise for the near term may be the hybrid vehicle. While not exactly zero emissions, hybrids are low emitting vehicles that are fuel efficient, and have performance as good or better than gasoline-powered vehicles. Hybrids use an internal combustion engine and an electric motor, thus avoiding the range limitations of electric vehicles.

This is not just a "pie in the sky" idea. The Toyota Prius is on the market already, and the Honda Insight should be available in the near future. These vehicles use electric power at low-speeds and at idle, but move to gasoline when more power is necessary. The gasoline engine also shuts down when the car is going long distances or when stopped in heavy traffic. By moving between electric and gasoline as power needs change, the gas mileage for the vehicle is nearly double that of a typical gasoline-only powered vehicle of a comparable size. Hybrids use regenerative braking, which means that energy from forward momentum is captured during braking and then used to recharge the battery.

Where is the American Hybrid?

U.S. car companies are not far behind in the race to offer hybrids. The American companies pooled their resources with the federal government in a six year project, known as the Partnership for a New Generation Vehicle (PNGV), to develop fuel-efficient environmentally friendly vehicles. The vehicles under development use a combination of hybrid technology and new materials to achieve huge gains in fuel efficiency and emissions reductions

Introductions of hybrid vehicles by Ford, GM and DaimlerChrysler are still a couple of years away, and there has been considerable controversy in Congress whether to continue funding PNGV. Critics on Capital Hill point out that despite the hundreds of millions of dollars spent on the project, the Japanese appear to be moving ahead of the U.S. companies in commercialization.

Whatever the result of this political battle, it is clear that hybrids will be a major part of the U.S. vehicle fleet in the coming years. The U.S. Energy Information Administration (EIA) recently announced that they believe that hybrids will be second in sales to internal combustion engines, although they add that it will be a distant second, possibly only seven percent of the fleet by 2020. Of course, fuel prices, government mandates and technological advances could dramatically change this dynamic.

The Technology After Hybrids

While hybrids offer emissions reductions, they are not zero emissions vehicles. Hybrids buy time until the next technology is ready for launching. One technology that may be a prime candidate is hydrogen-powered fuel cells.

Fuel cells act like batteries, except they do not run down. The Proton Exchange Membrane (PEM) fuel cell that is currently receiving the most attention from scientists consists of two electrode plates on either side of an electrolyte membrane. Oxygen is presented to one electrode and hydrogen to the other. The reaction, helped by a thin layer of platinum catalyst bonded to either side of the membrane, creates electricity, water and heat. Protons from the split hydrogen atoms flow through the membrane and electrons flow outside the cell from one electrode to the other, powering the engine.

For those of us who slept through science courses, the important things to remember about fuel cells are that they only emit water vapor into the atmosphere and that the hydrogen used in the conversion can be created by any number of fuels including methanol, ethanol, natural gas and gasoline. However, the fuel must be sulfur free.

Fuel Cells Are Still a Long Way Off

The possibility of using fuels other than hydrogen could be critical to the short-term potential of fuel cells, since hydrogen is not as dense as gasoline and therefore difficult to store on-vehicle. Solving the fueling infrastructure problems presented by hydrogen could take years.

Unfortunately, use of other fuels besides hydrogen pose difficulties. Converting gasoline or other fuels to hydrogen requires the use of an on-board reformer that can extract the hydrogen from the fuel. These systems, as currently developed, are inefficient and require high temperatures.

Exxon recently announced that, in cooperation with GM, they have developed an efficient method for converting gasoline to hydrogen. If this method bears out in real world demonstration projects, it could eliminate fuel storage and infrastructure problems preventing near term implementation of fuel cell technology. Mitsubishi recently announced that it is testing a methanol-powered fuel cell vehicle. While the infrastructure for methanol is not as developed as gasoline, it is considered a good candidate for fuel cell powered vehicles because it contains large amounts of hydrogen and is sulfur free.

With the favorable performance and emissions reduction potential of fuel cells, car companies are eager to get them into production. While prototypes of fuel cell vehicles are already being tested, car companies, depending on whom you talk to, claim that this technology won't be on car lots for some time. One of the major impediments to production is that the cost to manufacture fuels cells is considerably above what is necessary to build a competitively priced car. The car company that significantly reduces production costs will have a leg up in the race to get a fuel cell powered vehicle to market first.

The Possible Solution

There seems to be a consensus developing among engineers that, based on the absence of sacrifices for driving range and performance, fuel cells could be the long-term answer to the zero emission vehicle question. In fact, the South Coast Air Quality District in California, in partnership with the Air Resources Board, EPA and the Department of Energy, has invested billions in demonstration projects on fuel cells, attempting to move this technology along.

Will fuel cells be the answer to our clean air problems? It is too early to make that determination. However, progress on development of hybrids and fuel cells technology gives reason to hope that both the regulators and motorists will get what they want, and the environment and fuel economy will benefit as well.

The author would like to acknowledge the technical assistance provided for this article by Wendell Powell of Standard Motor Products.

Reprinted with kind permission by the Automotive Aftermarket Industry Association.