Editor’s note: This is the first in a four-part series that explores the sometimes symbiotic relationship between military and consumer technology. Over the years, technology developed by one sector has been adapted by the other for its own purposes and, in some cases, become even more ubiquitous in that sector. Future articles will focus on radar, satellite communications and weapons.

Today’s car buyer can walk into a Honda or Toyota dealership and ride out with a piece of transportation’s future: a vehicle that produces its own energy and is no longer driven solely by an internal combustion gasoline engine.

Soon, other consumer car and truck manufacturers will begin selling vehicles with similar characteristics. And just a few years from now — 2006 is the target — such vehicles will become part of America’s military motor pool. As you read this, our military teams are testing or developing multipurpose and tactical vehicles that are powered by something other than the various internal combustion engines that have been the heart of motorized transportation for over 100 years.

There are several different power sources for these cars and trucks, known collectively as “alternative fuel vehicles.” Propane-driven taxis have been in service for years, and Ford and Honda both have produced consumer vehicles powered by propane. All-electric vehicles also are on the road in limited quantities. There is even an annual race for prototype electric vehicles powered solely by solar energy.

General Motors, DaimlerChrysler and other manufacturers are working feverishly to develop vehicles powered by “fuel cells,” a technology that sounds like something from a 1950s science fiction movie. Today’s fuel cell prototype vehicles extract hydrogen particles out of a source, such as methanol, and use that hydrogen to create a chemical reaction that produces electricity. Their waste product is primarily water vapor. Unlike fossil fuel burning engines, they are fueled by a renewable resource and don’t pollute.

Some experts predict that it will be at least 20 years before fuel cell-powered vehicles are ready for mass production. They also question whether the other types of alternative fuel vehicles mentioned will ever prove practical enough for mass production.

There is, however, one type of alternative fuel vehicle type that is already being mass produced and seems very well suited to military applications. These are called “hybrid” vehicles because they are driven by two different power sources working in congruence. Today’s hybrids are powered by a traditional internal combustion engine and an electric generator and motor (often one unit).

Hybrid vehicles fall into one of two classifications. A “parallel” hybrid delivers power to its drive wheels from two different channels. Its propulsion can come from its gasoline engine, its electric motor or both. A “series” hybrid is driven by only one power source, its electric motor. Its internal combustion engine serves only as a generator, producing energy to power the electric motor or charge its batteries.

All hybrids are designed to be self-sufficient when it comes to obtaining the electricity used to power their motors. Because they contain onboard electric generators and storage systems (batteries), they should never need to be plugged into an external power source for recharging.

The first modern hybrid sold to the American public was Honda’s Insight, a two-passenger coupe whose low-slung, wind-cheating body looks like it was designed by a sci-fi comic book illustrator. Introduced in the U.S. in 1999 and still available, it pushed the envelope of automotive engineering and gave Honda a foundation on which it could build future models.

Insight got competition in 2001 from Toyota’s Prius, a more mainstream vehicle in appearance and functionality. Prius, which Toyota calls “the world’s first massproduced hybrid vehicle,” has four doors and can accommodate five passengers. Not to be outdone, Honda in 2002 introduced its second gas/electric hybrid. The Civic Hybrid, a five-passenger, fourdoor model, looks and feels very much like other Civics, despite being powered by cutting-edge technology.

Although the Honda and Toyota models are gasoline/electric hybrids, they differ somewhat in the way they operate. Toyota’s Prius is powered solely by its electric motor until it is moving 10 15 mph. At that point its small, four-cylinder gasoline engine is started and takes over, simultaneously driving the vehicle and generating power to charge Prius’ 110-pound battery pack. The electric motor kicks in if extra power is needed, such as while climbing hills or passing on the highway, or when the vehicle’s speed drops below 15 mph.

The gasoline engines on Honda’s hybrids (a three-cylinder on Insight and a fourcylinder on Civic), on the other hand, propel the vehicles whenever they’re moving. These engines shut down at stoplights, but start automatically when the brake pedal is released or the transmission is shifted into gear. Like Prius, the electric motors in Honda’s hybrids automatically provide a boost for accelerating or climbing. Also like Prius, the Honda hybrids’ batteries are charged by the gasoline engine and by circuitry that captures energy generated by braking.

All of this energy production and power allocation takes place automatically and nearly imperceptibly. The Honda and Toyota hybrids perform and feel like conventional vehicles. Only their graphic display gauges, absence of mechanical engine noise at idle and remarkable fuel economy suggest that they are anything but conventional. With an EPA rating of 61 city and 68 highway miles per gallon — more than three times the mileage of the average gasoline-powered SUV — Insight is America’s most fuelefficient passenger vehicle. Civic Hybrid and Prius are close behind.

And America’s military is not far behind when it comes to getting its own hybrid electric-powered vehicle on the road. According to Don Jarosz, public affairs spokesman for the U.S. Army’s Tank automotive and Armaments Command (TACOM) in Warren, Mich., a hybrid electric high-mobility vehicle is currently being evaluated at test centers in Aberdeen, Md.; Yuma, Ariz., and Ft. Greeley, Alaska.

Jarosz states that the vehicle being evaluated is a series hybrid. According to an ArmyLINK News article by Gerry J. Gilmore, the military vehicle’s propulsion system uses the same private-sector developed technology employed by six hybrid electric buses being tested in New York City.

In that propulsion system, mechanical energy from a diesel-fueled internal combustion engine drives a 120-kilowatt generator. Electricity from the generator charges a 2,000-pound battery pack and feeds two electric motors, each connected to a driveshaft (one connected to the two front and one connected to the four rear wheels). The onboard battery pack stores enough energy for the vehicle to operate with the internal combustion engine shut off.

This capability makes hybrids much stealthier than conventional military vehicles. Other major benefits of series hybrid electric military vehicles are reduced emissions, better fuel economy and the ability to generate ample electrical power for onboard and auxiliary equipment, such as radar and weapons systems. Jarosz states that hybrid military vehicles are expected to reduce fuel consumption by 30 percent. He points out that military fuel can range from $40 to $400 per gallon when transportation and manpower operational costs are factored in.

The Army’s goal is to begin full testing of its current hybrid in mid 2004, with production scheduled to begin in 2005. Deployment is slated for the following year. Also, there are projects underway to develop hybrid Medium Tactical Vehicles, a Heavy Expanded Mobility Tactical Truck and an M113.

These projects have benefited from Department of Defense initiatives to develop alternative fuel technologies in conjunction with the private sector. Although military and civilian transportation needs and requirements are often quite diverse, both face the same drawbacks with conventional vehicles: dwindling fossil fuel supplies and increasing pollution. Hybrid electric vehicles may be the best bet for addressing those drawbacks over the next couple of decades.