HEVs - Here to Stay?

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The first Hybrid Electric Vehicles (HEV) were produced in the early 20th century.  Then, as now, the HEV is a compromise between the limited range of the Electric Vehicle (EV) and poor low speed performance of the Internal Combustion Engine (ICE).

At the turn of the century the Electric Vehicle (EV) was the most popular type of automobile and expected to take over from the steam engine.  Lacking in noise, vibration and smell, the EV appeared to have a promising future.  But what it had in promise, it lacked in range.  Although ideal for city driving, the EV needed significant advances in battery technology before it could become a long distance vehicle. The Internal Combustion Engine (ICE) automobile on the other hand could travel as far as a tank of gasoline would permit.  But what it lacked was an automatic start capability and power at low speed.  So inventors toyed with dual power sources, gasoline and electricity, now known as a Hybrid Electric Vehicle (HEV).  The electric motor would provide the start and power at low speed while the ICE would extend the vehicle's range. There were two types of hybrid vehicle:  series and parallel.  The parallel hybrid was demonstrated in 1897 by Justus Entz, the chief engineer at a battery company in  Philadelphia.  The vehicle consisted of an ICE assisted by an electric motor.  Unfortunately the prototype was destroyed when an electical spark ingnited the fuel tank. Also in 1897 a young man by the name of Ferdinand Porsche obtained two patents, one for a motorized wheel hub, and the second for a series-hybrid propulsion system.  In 1900, while employed by Jacob Lohner, Porsche built a front-wheel drive vehicle followed soon after by a four-wheel drive version.  The storage battery weighed approximately two tons so a pair of one-cylinder IC engines were added to extend the operating range.  The ICEs powered a generator which in turn powered the four wheel-mounted electric motors.  It was called the "mixte" (mixed) propulsion system and was used to power fire-fighting equipment, military vehicles and Mercedes automobiles. In 1900, a Belgian carmaker called Pieper, manufactured a vehicle which had a small gasoline engine mated to an electric motor under the seat.  When the car was cruising the electric motor acted as a generator and was used to charge the batteries.  When the car was climbing a hill, the electric motor gave the gas engine a little extra boost.  Commercial vehicles were produced until 1912. Although significant improvements had been made in battery technology by 1910, including the development of the lead-acid and nickel-iron batteries, it was too late.  Most of the issues had been worked out with the ICE and the gasoline-powered vehicle began taking over the market.  The HEV did have continued success with trucks and farm equipment but the mass automobile market had been won by gasoline. Now fast forward a century to the late 1990s.  Car manufacturers were still struggling with battery technology, making the EV impractical.  Pollution was becoming an environmental concern and new ways (and old) were being explored to improve the gas mileage of the automobile.  Toyota introduced the Prius, a modern version of the HEV.  One big difference between now and a century earlier was the introduction of regenerative braking, where the energy from braking is recaptured and used to recharge the battery.  The regenerative braking technology was made practical by use of an electric motor with batteries.  Regenerative braking is also a century old technolgy, used in electric trains where the excess electricity generated while going down hills was fed back into the third (electrical) rail.  Unfortunately, there was no foresight to marry the HEV with regenerative braking back then.  In any case the HEV was too expensive compared to gasoline-powered automobiles. The question remains whether or not the Toyota Prius and other hybrids that have been introduced recently are too expensive for the general comsumer.  As in a century earlier, the HEV may be just a stop-gap until other technologies improve enough to meet tough new environmental standards.  Wouldn't it be something if we went full circle?  In the early 20th century we went from EVs to HEVs to the ICE.  Early in the 21st century we could conceivably reverse this path and go from the ICE to HEVs to EVs, reversing a century of environmental abuse by gasoline engines.  Just food for thought.