The Eco-car – Which Will Become the Front Runner? Hybrid, Electric, Fuel-cell – Requirements for Success

Alternative vehicles must meet many requirements they should emit minimal or no carbon dioxide or toxic substances, either in the vehicle itself or in the manufacturing process, the power source must be universal and supplied continuously, and the fuel or power supply facilities must be widespread and accessible. Electric automobiles represent one alternative, and there has been a great deal of rigorous research and development underway for many years.

An electric automobile uses a motor as its power source. There are actually three types of vehicles: electric, hybrid, and fuel-cell. The advantages of these cars are largely the same, and when they are compared with the ICEV: (1) the carbon footprint is tremendously low (as well as being highly efficient), (2) there is a large energy shift effect, (3) the ride quality is good (no gear shift shock, low noise, and low vibration) and (4) the environmental load is minimized (zero emissions, low noise). There are also many disadvantages such as: cost, onboard energy issues (shorter driving distance), and energy supply issues (recharging takes a long time and a new infrastructure must be put into place). These issues have been obstacles preventing these cars from becoming widely available.

At the moment, the only electric car that has been commercialized is the hybrid. Automobiles like the Toyota Prius, Honda Insight, and others have been very popular even during this economic downturn. It is expected that there will be more cars of this type and they will achieve explosive sales. This simple hybrid method is clearly far more in tune with environmental expectations than the ICEV, but it is the least efficient among the electric car family. This means that auto manufacturers must further research and develop an electric car that has even less impact on the environment.

Even though it is still in the distant future, perhaps in the 22nd century, we will one day run out of fossil fuel for automobiles. The major players then will be electric, fuel-cell, or plug-in fuel-cell cars (a system midway between electric and fuel-cell vehicles). However, because lithium-ion battery and fuel-cell technologies (the core technologies in electric cars) have yet to mature, it is simply not possible to suddenly jump from a hybrid car to a fuel-cell car. A long transition period is needed for the ultimate electric car to come into widespread use—supplying and using non-fossil fuel(s).

During this period of transition, there will be many methods developed indiscriminately. We don't really know how the performance of lithium-ion batteries and fuel-cells can be improved or how much the cost of the vehicle can be reduced. These uncertainties contribute to these longer transition times and haphazard methods. More recently, simple hybrid cars have become more popular and new candidates will emerge as “special-purpose electric cars” or “plug-in hybrids”, etc. The former can be further categorized into “mid-range commuter cars” or “short-distance/frequently-charged cars.” These three types of electric vehicles will emerge in the near future. This will be the beginning of the diffusion of true electric cars in which electric energy is used as fuel i.e. the power source.

The mid-range commuter automobile can be defined as a small electric vehicle. Since this type of car has limited usage, the battery problem the biggest obstacle in developing an electric car is easily solved. For example, the driving range of an ICEV (passenger car) is 500 – 600 km but a “commuter car” cannot be driven for such a long distance, and a 50 – 150 km driving range should be sufficient. This type of vehicle requires neither a high maximum speed nor a high-level of air-conditioning performance. For these reasons, there are not many technological hurdles to development, and many cars may be marketed, possibly by the end of this year or next. (Examples include: Subaru’s plug-in Stella, Mitsubishi’s i-MeEW, and Nissan’s model.)

The second candidate, short-distance/frequently-charged, is the result of trying to overcome the problem with batteries. In an electric car, the biggest problem is always the battery: it is heavy and big, which leads to cost and performance issues. Short-distance driving and fast charging should reduce battery size and weight, thereby solving the battery problem. This method can be implemented in such vehicles as city buses, garbage collection trucks, and campus or in-house vehicles—all of which have limited driving ranges, routes, and fixed electricity-charging stations. Currently, half the cost of an electric car is the battery itself. This method provides big savings: lighter weight directly reduces power consumption. Waseda University has devoted many years to research and development aimed at applying this method to a “community bus.” (See: Figures 1 and 2.) We also successfully developed a unique charging device. While frequent charging is a critical feature of this method, the device allows the user to charge the car frequently in a way that is safe and fast: using a non-contact rapid inductive battery charger that has the highest charging performance in the world.

It is expected that many plug-in hybrid cars will soon be available. A plug-in hybrid is midway between an electric car and a hybrid car, running not only on gasoline but also on electric energy. The plug-in hybrid power system is more complex, and it increases vehicle weight. If this type of car was in greater use in Japan, the shift to clean electric energy would bring about additional benefits by further reducing the carbon footprint and energy costs compared to the conventional hybrid.

I have stated my personal views on the future of electric vehicles by focusing on the near future. To massively popularize the ultimate electric, fossil fuel-free vehicle, it is necessary to develop cars that effectively take advantage of electricity and to use them in an intelligent manner. The ICEV reached its current level of performance (e.g., long driving range) after many years of improvements to the combustion of liquid fuel, and it is natural that the features of a car should change along with the energy that it uses. If we want an eco-car, we should not expect the same functionality as with a conventional vehicle. It is necessary to change the mentality of users to popularize electric vehicles so they become “friendly” to both people and to the earth.

Yushi Kamiya
Professor, Faculty of Science and Engineering Waseda University
Background
March 1993 Graduated from Electrical Engineering Department School of Science and Engineering Waseda University
March 1997 Completed the Doctoral Program Electrical Engineering Department School of Science and Engineering Waseda University Professor (Engineering), Waseda University
April 1998 Technical Researcher Traffic Safety and Nuisance Research Institute Ministry of Transportation
April 2000 Full-Time Instructor, Gunma University
April 2007 Associate Professor Graduate School of Environment and Energy Engineering Waseda University
April 2009 Professor Faculty of Science and Engineering Waseda University
Publications
Fuel-Cell Cars, Transportation Theory – Fun Seminar 2, Culture of Transportation and Vehicles – From Rickshaws to Roller Coasters (Seizando, 2008)
Advanced Electric Microbus – Making City Buses More Attractive: Perspectives in a New Era (Jomo Publishing, 2006)

Fuel-Cell Automobiles – Features, R&D and Verification Test Trends: Everything about Fuel-Cell Automobiles- World Trends (Sankaido, 2005)