Cochairman MUSKIE. Our next witness is Mr. Marshall D. Aiken, electrical engineer, Headquarters, U.S. Army Materiel Command, Department of Defense.

STATEMENT OF MARSHALL D. AIKEN, ELECTRICAL ENGINEER, HEADQUARTERS, U.S. ARMY MATERIEL COMMAND, DEPARTMENT OF DEFENSE; ACCOMPANIED BY DR. G. FRYSINGER, CHIEF, POWER SOURCES DIVISION, AMC-ECOM, FORT MONMOUTH, N.J.; T. KIRKLAND, CHIEF, ELECTROTECHNOLOGY DEPARTMENT, AMC-ERDL, FORT BELVOIR, VA.; AND R. E. HOPKINS, CHIEF, POWER TECHNOLOGY LAB. AMC-ERDL, FORT BELVOIR, VA.

Mr. AIKEN. Mr. Chairman, the Army was chosen to represent the Department of Defense at these hearings due to the invested Army interest in land vehicles, and also due to the diversity of power source programs which are pertinent to advanced vehicle design.

The Department of Defense is not in a position to evaluate the potential of new concepts in propulsion for civilian vehicles. However, in order to present testimony which will be meaningful to these hearings, some assumptions pertaining to civilian vehicles must be made.

First, it is assumed that the necessity for reduction in air pollution will dictate that new concepts in vehicle propulsion must come about, even at the possible expense of some inconvenience to the public.

Secondly, if electric cars are to be introduced in the next few years, performance, payload, and daily operating range may be limited to the capabilities we can provide with lead-acid batteries.

It is not possible to predict at this time which type of propulsion system will be best for future generations of vehicles, whether it will be new concepts in engine design, or a battery or fuel-cell-powered electric vehicle. It is further not possible to predict which of the new battery concepts is most likely to succeed as a practical power source for electric vehicles.

The Department of Defense has extensive R. & D. programs for batteries, fuel cells, auxiliary power units, new engines, solid state power controls, and complete electrical propulsion systems. None of these R. & D. programs are designed to meet the peculiar requirements for commercial automobiles; however, the Defense R. & D. programs should contribute significantly to eventual design of practical commercial vehicles with low emissions of air pollutants.

The lead-acid battery is considered to be the only practical storage battery available today for large volume production. The principal limitations of the lead-acid battery are its low-energy storage density and low-cycle life with deep discharge. Defense laboratories are investigating unique new battery systems for military applications, including zinc-air, lithium chlorine, and lithium metal halide types. Predicted energy densities range from 50 to 150 watt-hours per pound, as com

pared to approximately 10 watt-hours per pound for lead-acid batteries. Some of these battery investigations are specifically for vehicle propulsion. All of these high-energy density battery designs, including those being investigated by industry, are in the experimental stage, and years of development are required to bring any of these batteries to the stage where they will be suitable for high-volume production. Of the high-energy density batteries mentioned, the zinc-air in a primary type is probably nearest to the hardware stage. A secondary, or rechargeable, zinc-air battery is a long way from being ready for vehicular use.

Defense laboratories have been actively investigating and developing fuel cells for over a decade. The primary goals are silent operation, high efficiency, and long operating life without maintenance. Most of the military applications call for air-breathing fuel cells, as opposed to using pure oxygen as in spacecraft. The fuels under consideration for military applications include hydrogen, ammonia, hydrazine, and hydrocarbon fuels. Portable systems with 60- and 300-watt outputs will be fielded for test in the current year, using hydrazine as a fuel. A military-type 34-ton truck powered with a 20-kilowatt hydrazine-air fuel cell system has been fabricated as a test bed. It is not proposed that hydrazine will be a suitable fuel for vehicle propulsion, although ammonia, which can be used in a similar system, may find some application in the future. Hydrogen is ruled out as a practical vehicle fuel due to storage and handling problems.

The use of kerosene type or JP-4, hydrocarbon fuels in a fuel cell is nearing successful development for portable electric power generation. The hydrocarbon fuel is reformed within the system to provide hydrogen. Å 500-watt prototype unit has been delivered, and a 11⁄2kilowatt prototype is due later this year. Both of these units use platinum or other noble metals for catalysts. Until suitable catalysts can be found using low cost and readily available materials, this type of fuel cell is probably ruled out for vehicular propulsion.

In order to eliminate requirements for expensive catalysts and to obtain a higher power density, the Army is investigating a hightemperature fuel cell using a molten salt electrolyte. Research on this type of fuel cell has progressed sufficiently to warrant an exploratory development program starting this year for a 10-kilowatt system. The high temperatures and long startup time may render this system unsuitable for commercial vehicle applications.

Fuel cells which will be practical for commercial vehicle propulsion may be at least 10 years away.

Dr. Hollomon mentioned steam engines earlier. This brings up a real interesting concept in the use of the steam engine with an electric car. No one has mentioned to date, that I know of, how we are going to heat the electric car. Even a small car will take about a 10,000 British thermal unit capacity heater. This means 3 kilowatts if you do it electrically, which for lead-acid batteries will take about 300 pounds of

batteries to provide this heat for 1 hour. However, the Army is investigating small steam engines, as Dr. Hollomon mentioned. These are for generators rated at less than 3 kilowatts. However, they will replace in a car, pound for pound, an equal amount of batteries as a propulsion system, keeping the battery charged, and at the same time will provide more than the necessary heat for the car.

In addition, a lot of the batteries need to be kept warm themselves in order to get the range and the performance that you start out with. So these could also be used to heat the batteries in the car.

For instance, a car that might have a 50-mile range could, with a 1kilowatt steam engine generator, keep the car heated and at the same time not take up any extra weight because it would also reduce the weight of the batteries by an equal amount.

This same system, though, every time you stop at a stoplight, or for any other reason, would tend to keep the batteries charged and would increase the range of an electric battery powered vehicle to possibly even double that which you would get with an equal quantity of batteries.

We are not at the present time developing any steam engines for vehicular propulsion, although it has been considered. The steam engine isn't the only system which would be appropriate for use as an auxiliary powered unit in a vehicle for both heating and for keeping the batteries charged. A thermoelectric generator, or other types of closed Rankine cycle engines, could be used. These use an external type burner which does not have the pollutant problem that you find in an internal combustion engine. And the closed cycle steam engines of course do not require water makeup.

There are other engine developments in the Department of Defense which should contribute to practical solutions for vehicle propulsion with low emission of pollutants. A hybrid engine under investigation at the Army Tank and Automotive Command, in which excess air is provided in the combustion chamber, should eliminate practically all emissions of unburned hydrocarbons. Investigations of new engine concepts is recommended as a backup in the event development of battery operated commercial vehicles is found to be impractical or too distant. The hybrid engine, external combustion engines and vehicular gas turbines are among the new concepts under development by Defense agencies which may be of interest in order to reduce air pollution in commercial vehicles.

Electric vehicles, whether powered by batteries or other sources of electric power, will require unique power control systems. Defense agencies have considerable experience in development of solid state

power converters of types which will contribute to systems necessary for commercial vehicles. Much of this work is aimed at reduction of cost, weight and complexity and to obtain improved reliability.

The Army has fabricated a number of test bed vehicles using electric power. The use of electric motors to power each wheel is a concept which is under intensive investigation, both in tactical and earthmoving vehicles. In order to obtain significant improvement in mobility and flexibility, we have turned to the electric wheel drive.

In addition to the fuel cell powered truck mentioned earlier, test bed vehicles using turboalternators or conventional engine generators are under study. Both a.c. and d.c. drive systems have been built, using solid state power controls. Much of the technology in electric power sources, drive motors, and control system on these vehicles will apply to design of commercial vehicles with electric drive.

Most of the Defense effort in batteries, fuel cells, new engine concepts, electric drive, and other advanced vehicle propulsion systems is unclassified. Reports of past, current, and future effort in these fields can be made available to industry and to other U.S. Government agencies to contribute to development and design of new vehicles for commercial applications.

I have looked over a list we have of fuel cell and battery studies under the Department of Defense and NASA and AEC. There are 165 studies underway at this time on batteries and fuel cells under these agencies. These are not necessarily aimed at the electric vehicle drive, but all of these studies could contribute to the technology necessary for this.

Čochairman MUSKIE. Could we have a list for the record?

Mr. AIKEN. Yes; I can give you a list for the record. That is in addition to the report that has been passed out.

The Department of Defense is coordinating with the Department of Commerce in their panel study on this subject and feel that these bills should await the results of the Department of Commerce study before determining whether or not we should actually go into designing commercial type vehicles with Government funds. However, we do feel that intensive research is appropriate for Government funds.

Cochairman MUSKIE. Thank you very much. I think it would be very useful to include this document in the record. It is very well prepared and I think lays out the present state of the art as you see it in an understandable way. Without objection it will be included in the record.

(Subsequently the following tabulation was submitted:)