Electric Vehicles

• How Do They Work?
• Outlook
• Where Do We Go from Here?

Before the IEA HEV Agreement, no data on the number of electric vehicles (EVs) had been collected from official sources. Since the beginning of the agreement, a good deal of information has been recorded that could form the basis for an international database of EV statistics. Despite the uncertainties and difficulties in collecting data, information on statistical trends and technology evolution is valuable in the assessment of the status of EVs.

How Do They Work?

There are currently three types of EVs: battery electric, hybrid electric, and fuel cell electric. Hybrid electric vehicles are described here. Fuel cell electric vehicles are in the prototype, testing, and demonstration phases. Battery electric vehicles work by storing electricity from the grid in a large battery that is used to drive an electric motor, which drives the wheels of the car.

Several conversions are necessary, because electricity from the grid is in the form of alternating current (AC), and a battery can store only direct current (DC). When the battery is charged, the charger converts the AC to DC and supplies it to the battery at the correct voltage. Some electric vehicles are powered by AC motors; in this case, the DC from the battery must be converted to AC again by an electronic device called the inverter, and it is also necessary to control the amount of power supplied to the motor and wheels of the car. Other EVs are powered by DC motors; in this case, the DC from the battery must be controlled to give the correct amount of power to the motor. This is done by an electronic device called the controller.

The distance that an EV can drive before the batteries need recharging depends on the type and number of batteries installed in the vehicle and can range from 50 to 200 km. This limitation can be overcome in two ways: one is to install fast-charging facilities, which can recharge the batteries in 10-20 minutes, and the other is to improve battery technology. In the past decade, rapid progress has been made in battery technology. The lead-acid battery was surpassed in efficiency and power density by nickel-cadmium and then nickel-metal hydride batteries. These newer batteries are already important in commercially available hybrid vehicles. Advanced technologies, such as lithium-ion and lithium-polymer batteries show promise in vehicle propulsion applications. The costs of these newer technologies are still high, but they are decreasing steadily.

Outlook

The outlook for an increased role for EVs in the world market is quite promising; however, vehicle numbers may have reached a stagnation point. There are several reasons for this:

1. Only a few important European car producers offer affordable EVs in selected markets, but at prices that are higher than those for comparable conventional vehicles.
2. European manufacturers are designing better internal combustion engine vehicles with enhanced power trains and gasoline direct-injection (GDI) and turbo direct-injection (TDI) drives, which offer energy efficiency and high performance.
3. Attractive EVs from Japanese producers are available only in very selected markets and in small numbers.
4. Car dealers around the world are not motivated to offer or sell EVs.
5. New vehicle and technology concepts, such as "3-litre cars" in Europe (80 mpg) or fuel cell vehicles make potential customers uncertain as to the current state of EVs and induce them to put off the buying decision.

• Coordinated action from governments concerning promotion programs and mandates for EVs, a quick but potentially expensive option, and
• Promoting EVs in market niches and expanding the niches step by step. This could be politically simpler but would be a less effective method.

Where Do We Go from Here?

Surveys in America, Asia, and Europe have shown that many people drive their cars less than 50 km per day, and most people drive less than 100 km per day. Battery electric cars available today can meet the mobility needs of many urban households, but they usually do not meet customer expectations when they are buying a car in the showroom. There are two broad responses to this challenge: one is to continue to improve battery technology and reduce costs, and the other is to address the customer expectation issue.

Improvements in battery technology are being driven by demand in cell phones and laptop computers, where customers are prepared to pay very high prices for high-performance batteries of a relatively small capacity (compared with vehicle batteries). Lithium-ion batteries are now widely available for laptop computers; this is a particularly promising technology because the material cost of lithium is relatively low compared with that of nickel. The current cost of lithium batteries would have to decrease significantly before they become practical for vehicles. This may well happen over the next 5-10 years. In addition, there are several other technologies based on zinc, sodium, and other metals that are not considered frontrunners at this time but that may yet emerge as competitors in the future.

The customer expectation issue may be addressed by designing different cars, or by cultivating different expectations among customers. The neighborhood electric vehicle is an example of designing a different car. It can be driven only on roads where the speed limit is less than 60 km/hr, and it usually has no sides or windows, except for a plastic curtain that can be zipped up if it rains. It can be used for shopping trips, taking a child to school, visits to friends, etc. Because it is open on the sides, it is easy to stop in the middle of a quiet street and have a chat with neighbors. Customers who see the car immediately have a different set of expectations than they do for a conventional car. Other examples of designing a different car are bubble-shaped two-seaters, or racy-looking sports cars.

Cultivating different expectations among customers is often done with respect to fleet owners. Some cars in a municipal fleet or postal delivery service drive less than 40 km per day. If the customer were made more aware of his or her objective transportation needs, he or she may be quite satisfied with the purchase of an EV. In Switzerland and Austria, some tourist villages have banned conventional cars and allow only EVs. They then promote the clean air and quiet atmosphere in their publicity materials. This is another example of changing customer expectations.

Designing innovative cars and changing customer expectations may result in success in certain market niches, and this will be important for the continuing development of the technology. However, there are many important market segments where EVs would be competitive only if progress in battery technology and cost reduction is sustained for another decade or more. It is possible that the hegemony of the internal combustion engine will end during the next two decades, and the car market will become segmented among different technologies, including high-efficiency gasoline engines, low-emission diesel engines, hybrid vehicles, fuel cell vehicles, and battery electric vehicles.