limited application or short range "shopper" vehicle-something between our Electrovair II and a golf cart.

Such a vehicle might be useful for local shopping, driving to the commuter station, school transportation, community service deliveries or other short-distance and limited transportation tasks. Based on the technology available from the golf cart type of vehicle, a special-purpose car could be designed to do these specific tasks.

Certain limitations compared to current all-purpose cars will likely have to be accepted. Top speeds would range up to 40 miles per hour. This could be a safety hazard if intermixed with larger, higher performance automobiles on urban expressways. Since its acceleration ability and top speed are too low, such vehicles could not be used on modern expressways, turnpikes, or other main roads or streets where speeds above 40 miles per hour are maintained.

Also, driving range of the "shopper" under ideal conditions would be less than 40 miles and interior space would be limited. The price level for these vehicles, including necessary safety, convenience, and operational features, would approximate the low range of the present domestic passenger cars. In addition to the initial cost, replacement of batteries at least every 2 years could be expected to range from $200 to $300 in today's market.

Besides these economic considerations, cold weather and passenger compartment heating would place heavy burdens on the performance of the "shopper." Both the range and performance of any batterypowered car deteriorate in cold climates. At zero degrees Fahrenheit, a lead-acid battery will deliver only about 60 percent of the driving range and peak power that it will at 80°. A "shopper" that has a range of 40 miles on a 80° day would be cut back to a range of 24 miles on a zero-degree day if the heater were not used, and to a range of only 12 miles if the heater were used.

As to the various potential energy sources, those now receiving the most study include batteries, fuel cells, and molten metal systems. Our Electrovair is equipped with silver-zinc batteries because they offer the highest energy storage per unit of weight and the highest peak power output of any readily available battery today. These batteries give the Electrovair a range of up to 80 miles. Unfortunately, the very high cost and limited availability of silver place obvious limitations on this as a power source.

Lead-acid batteries would be much too large for cars with the performance characteristics of the Electrovair, while another type of battery-zinc-air-has limited peak power and is still in the laboratory

stage.

The fuel cells used in the Electrovan were developed by Union Carbide. They gave the van an acceleration performance equivalent to that of a gasoline-powered vehicle loaded to the same weight.

The Electrovan is a highly experimental vehicle, requiring extensive safety precautions for protection against high voltages, hot caustic potassium hydroxide and fire and explosion hazards from hydrogen and oxygen.

Our work indicated that fuel cells have certain real advantages over batteries, but there is need for development of less complex auxiliary systems, reducing the cost and weight of the fuel cells and the develop

ment of cells fueled by a solid or liquid rather than a gas stored under high pressure. In a production version, of course, it would be essential to package the fuel cells to guard against spilling these hazardous elements in a traffic accident.

Molten metal devices, which operate at high temperatures, are promising laboratory energy sources at this time. GM has been working on one of the molten metal systems, lithium-chlorine, for about 4

years.

At the present time, all high-temperature systems have disadvantages for automotive applications. These systems generally present startup and shutdown problems unless they are kept at their operating temperatures when not in use. One of the current needs is to develop a low-cost means of holding these molten metal systems at near their normal operating temperatures so that the necessary waiting time for warmup can be substantially reduced or eliminated.

Our work with lithium-chlorine cells has shown that extremely high densities of current can be achieved-higher than any other practical electrochemical reaction. We have operated multiple cells in series and have demonstrated that this system, if designed properly, can be recharged.

In addition to our work on electrical power research and development, we have investigated other low-emission powerplants. We have made constant efforts to improve our present internal combustion engines and lower their pollutant emissions, and we have studied many other combustion engines.

Alternative powerplants with low pollutant levels include the gas turbine, Stirling external combustion engine, and the steam engine. The technology involved in all these has been upgraded through the years and there is promise of even further gains in the future.

It is possible, of course, to develop systems which employ combinations of various power sources. For example, a combination of batteries and a combustion engine or fuel cells combined with storage batteries have been studied. All such systems, however, present difficult control problems, are complex, and are more expensive than single-power systems.

Based on research to date it is difficult to equal the internal combustion engine with any alternate power source on overall requirements. As we have discussed with Senator Muskie recently in Detroit, present technology indicates that the internal combustion engine offers the best compromise as to cost, durability, reliability, economy, performance, and efficiency-and I stress that the latter includes the control of pollutants.

Our research further demonstrates to us that we will be able to achieve very low pollution levels with the internal combustion enginelevels that are consistent with known ambient air quality objectives. Significant engineering developments have helped us bring automotive pollutants under control in California, which has had the worst problem in the country. We expect comparable improvements when controls are available nationally on all new cars beginning with 1968 models.

Our California experience offers an example of what can be accomplished nationally through improvements in the internal combustion gine and development of pollution control methods. Assuming a 10ar life cycle for automobiles, we believe that by 1978 virtually all cars

should be equipped with crankcase and exhaust control systems that would reduce hydrocarbon emissions 80 percent and carbon monoxide emissions 74 percent below precontrol pollution levels.

GM has been working on pollution research and hardware since the late 1940's, and we sincerely believe current programs particularly those related to the internal combustion engine-will result in continued progress toward solution of this important problem.

We believe electric vehicle propulsion is technically feasible, but our research has not shown when it would be economically feasible or acceptable to our customers. Normal competitive factors in our business require us to consider and develop any power sources which may have improved utility and benefit to all.

While we believe our industry can attain further substantial air quality improvements with our internal combustion engines at much less cost than any other proposals to date, we will continue to pursue vigorously the development of all potential sources of power having improved efficiency and lower pollutant levels.

Thank you for the opportunity to express our views on this matter of such great interest to the public, our customers, and to us.

(The attachments to Mr. Barr's statement which were ordered to be printed are as follows. The others appear in the committee files:)

GM ELECTROVAIR II

The battery powered Electrovair II is a test bed for motor and control developments. Its power source is a silver zinc battery pack in the front and rear compartments of a 1966 Corvair chassis. It is a second generation car, successor to an earlier version in a 1964 Corvair chassis that was operational in November 1964.

Silver zinc batteries were used because they deliver high peak power and provide good energy storage, but they are costly and wear out after 100 recharges. Electrovair II's performance is virtually the same as a conventional gasoline powered Corvair, except for its limited range of 40-80 miles before recharge. A tank full of gasoline will propel a Corvair 250-300 miles. Electrovair's total weight is approximately 800 pounds more than a Corvair, even with the comparatively light and compact silver zinc battery pack. If it were to be propelled by conventional lead-acid batteries, the batteries alone would weigh more than 2,600 pounds, approximately the total weight of a standard Corvair.

Basically, General Motors business is power conversion. Thus one of the major assignments of the Power Development group of General Motors Enginering Staff is to keep management informed of the latest power engineering developments. This would include all forms of conventional engines, plus any advances in the state of the art in battery, fuel cell, thermoelectric or thermionic techniques. This progressive engineering philosophy involves design, development, testing and analysis-not necessarily with specific future products in mind. The objective is to determine what is technically feasible, regardless of whether a project ever will become economically possible. The idea is to be ready for the future.

The GM electric vehicle concept is based on the belief that an electric car should have performance compatible with modern expressway driving. Such a concept rules out special purpose golf cart type vehicles. While such a vehicle could be used for shopping or errand running chores in a fairly self-contained community, vehicle operators would be at the mercy of overwhelming traffic odds. In the design of Electrovair II all of its systems-batteries, motors and controls were integrated. The overall system that evolved into this secondgeneration vehicle consisted of these components:

Battery pack

Silver-zinc batteries were chosen since this type of battery gives the highest energy storage per unit weight and highest peak power output of any available

battery, Electrovair I needed 242 batteries which weighed about 550 pounds. Four of those celis would supply the same energy as a léad-acid battery in a conventional car and would weigh only about eight pounds.

Motor

An AC induction motor was chosen to power the car. The induction motor is a very rugged machine which can be run at hgih speeds. This one deliveries about 100 hp, runs up to 13,000 rpm, and weighs only 1.3 pounds per horsepower.

Inverter-modulator (high power components)

The direct current power available from our battery pack must be changed into alternating current power for the induction motor. This is the job of the high power switching equipment which varies both the voltage and frequency of the power in just the right way to run the motor. This unit requires 18 of the most advanced silicon controlled rectifiers available.

Trigger box

To provide signals to turn those high power switches on at the proper time, low power trigger controls are required. They produce a pulse of energy which must peak in less than one microsecond or else the silicon controlled rectifier will burn itself up.

Logic box

The electronic logic box translates the driver's control from the ignition switch, the gear selector, or the accelerator pedal, into the proper signals to develop more power, less power, reverse the motor, or whatever is demanded. This box also contains the electronic safety circuits.

Oil cooling system

An oil cooling system is needed since our motor and electronic controls are not 100% efficient. The motor and controls are very compact and handle very high currents. Therefore, they must be cooled by circulating oil through them, and then through a radiator, which is cooled by air with a fan and motor.

GM ELECTROVAN

The General Motors Electrovan demonstrates that electrical propulsion by fuel cells is technically feasible. Studies leading up to the Electrovan date back more than ten years and have involved not only GM's central staff organization, but also several GM accessory divisions. In addition, major assistance was received from Union Carbide Corporation in developing the largest hydrogenoxygen fuel cell system of its kind in the world for Electrovan.

The system supplies a continuous output of approximately 32 kilowatts and a peak of 160 kilowatts, and consists of 32 thin electrode fuel cell modules in series beneath the vehicle's cargo space. Electrovan's range, with its liquid hydrogen and oxygen fuel tanks, is approximately 150 miles.

The fuel cell van program was started when it became apparent that modules would be available with power density high enough to make an experimental vehicle possible. The idea was to design a vehicle that could match a standard delivery van in acceleration, performance, and driving range.

In the process of getting ready for the future, General Motors engineers are continually investigating new ideas in many technical fields. The Power Develop ment group, one of many teams of specialists working at the General Motors Engineering Staff, has the task of keeping up to date on the latest developments in power conversion systems. This includes not only all forms of conventional engines, but also advances in the direct conversion of energy. The objective is to determine what is technically feasible, regardless of whether a project ever will become economically practical.

General Motors is aggressively supporting electrical propulsion development because of its ultimate potential-driving flexibility, smoothness, quiet operation, and theoretically higher efficiency. Research indicates, however, that major programs lie ahead if such power systems are ever to become practical. Complexity, size, weight, cost and operating hazards are among their obvious handicaps when compared with conventional automobiles.

A fuel cell is a device in which the chemical energy of the reaction of a conventional fuel and air (oxygen) is converted directly into useful electricity. A fuel cell differs from a battery in two major respects: It can operate continuously as long as fuel and air are available. It uses hydrocarbons (or some derivative such as hydrogen) for fuel.

The hydrogen-oxygen fuel cell reverses the well-known process of electrolysis. Instead of separating water into its components by passing an electric current through it, water is created in a controlled reaction which liberates energy in the form of electricity.