WHY ALTERNATIVE FUELS?

Growing concerns about energy security and exhaust gas emissions from vehicles have increased interest in alternative transportation fuels. One likely candidate for this is electricity.

The development of the electric vehicle has been an ongoing process for many years. However, the California Air Resources Board (CARB) Low Emission Vehicle(LEV) program has accelerated the development even more by passing legislation that requires at least two percent of the vehicles sold in 1998 meet zero emission standards. At this time, the only vehicle capable of such an achievement is the electric vehicle.

Current battery technology is the major setback for the electric vehicle. At this time a battery pack can weigh anywhere between 800 pounds and 1800 pounds. The lifetime of a battery is also a problem. The vehicles run for only a short range before the batteries must be recharged by a 120 to 240 volt electrical outlet. However, many of the auto manufactures and battery producers are working towards the advancement of battery technology.

As an interim solution to the deficiencies in the range of the current batteries, the hybrid electric vehicle has been developed. This vehicle is an electrically charged battery pack, coupled with a small internal combustion engine, capable of producing minimal emissions with a longer range than that of a battery run vehicle alone. Ultimately, the hybrid electric vehicle design is to be a cost-effective, highly efficient, ultra-low exhaust emission vehicle capable of equaling or exceeding present vehicle performance, safety and customer appeal standards.

HYBRID VEHICLE CONFIGURATIONS

• Hybrid cars have two power sources, mostly an engine and an electric motor. There are usually two on-board energy storage systems: a fuel storage tank for internal combustion engine and a battery for the electric motor. In hybrid vehicles, flywheel is used as a short-term energy storage device. In hybrid vehicle concept combines local zero-emission driving with long distance driving on the engine.
• There are two different approaches in hybrid vehicles, the series and parallel arrangements. The difference between them is basically related to the power transmission from the on-board auxiliary power unit (APU). In a series hybrid electric vehicle, electric power unit transmits the power to the road. In a parallel arrangement, the power transmission from the APU to the road can be achieved mechanically. In other word both electric drive unit and APU can transmit power to the road by applying different configurations.

Advancements in Battery Technology:

Once the battery technology in the electric and hybrid electric vehicle is refined, the possibilities for these vehicles are endless.

Currently, the lead-acid battery is the most widely used for this type of application. An international group of battery manufactures, who have formed a consortium to help advance the lead-acid battery technology, have outlined some research goals that they hope to achieve. These goals are not designed to help the electric vehicle reach the same range and performance standards set by the internal combustion engine. Instead, they have set goals that would be achievable in light of the current lead-acid battery technology.

• Increase the specific energy from 35-45 Wh/kg to 50 Wh/kg at a three hour discharge rate
• Improve the cost per battery pack at $150 per kilowatt-hour
• Improve the specific power of the vehicle to 150 W/kg at 80% depth of discharge.
• Improve the life cycle of the battery to three years or 500 cycles of the simplifies federal urban driving schedule with less than 20% capacity loss.
• Improve the rapid charging technology so that the lead acid batter can be fully recharged in less than four hours, 80% recharged in fifteen minutes and 50% recharged in five minutes.

Although the lead-acid battery is the leading battery used in electric vehicles today, there are many other options available. The nickel-iron, sodium-sulfur, lithium-sulfide, nickel-cadmium and zinc-air batteries are all being tested in electric vehicles and perform quite well. These various types of batteries are expected to increase the driving range and power in the electric and hybrid electric vehicle, but will cost considerably more. Continued research is needed to improve the battery driving range and reduce weight problems.

ADVANTAGES OF EVS

• Electric vehicles produce far lower emissions than any other fuel. They produce no tailpipe emission and even when the emissions from the electric generating plant are considered, EVs still rank the lowest.
• The electricity used to power electric vehicles is readily available and can be produced from a wide variety of sources including coal, natural gas, nuclear, solar and various other power sources.
• The resources used to power electrical plants are abundant here in the United States. Thus, greatly reducing our dependence on foreign resources.
• The "refueling" of the vehicle is convenient. An electric vehicle can be recharged at home by methods similar to plugging a major appliance into a 120 or 240 volt electrical socket.
• Electric vehicles have many small advantages to gasoline powered vehicles. The vehicle is easier to maintain, runs more quietly and is subject to special incentives such as subsidized or special parking .

Production

DISADVANTAGES OF EVS

• The cost of the vehicle is the greatest problem facing the electric vehicle. The price of an electric vehicle can average between $5-$10,000 more than a comparable gasoline powered vehicle. The batteries are expensive to replace and the cost per gallon equivalent to recharge the batteries is around $3.72. While utilizing a hybrid electric vehicle can bring this cost down, it still does not come close to competing with gasoline powered vehicles.
• The performance of the electric vehicle is lacking in many areas compared to conventionally fueled vehicles. The top speed of an electric vehicle is 65 miles per hour and the acceleration is slow. There is also a great deal of power loss while heating or cooling the interior of the vehicle. Another factor is that the batteries are bulky and they take away much of the cargo space.
• The limited range of an electric vehicle is also a major setback. For one charge, the average range is approximately 60 miles. However, this can change due to the outside temperatures as well as the amount of heat or air conditioning that is running. The battery can lose capacity quite rapidly in extremely cold temperatures. For example, when the outside air is around 20^o F, the battery capacity is decreased almost 50%. Here again, the hybrid electric vehicle basically solves the range problem. With the internal combustion engine working with the battery the range is not a major factor.
• Although the battery can be recharged at home, it takes a great deal of time. To completely recharge the battery, eight to ten hours is needed. An added problem to charging the battery is the lack of an infrastructure if you are away from home. Charging facilities need to be placed in convenient locations such as parking garages and hotel parking areas.
• As more and more electric vehicles are produced, the need for competent service and repair personnel becomes greater. Training for those who will be working with the vehicles needs to be more readily available. Also, emergency medical rescue workers need to be trained as to how to handle an electric vehicle related accident.

SAFETY ISSUES

• The acid in the battery can cause severe burns if the battery becomes damaged due to a collision or misuse.
• The disposal of the batteries may cause unique environmental problems. Although recycling is now available, a large surge in battery usage may make the battery recycling facilities inadequate.
• The use of high voltage needed to produce a "quick recharge", which is in the development process, can be dangerous if not done properly.