Bad Things About Hybrid Cars

by Edwin Thomas

Concerns over global warming and rising oil prices have focused attention on alternative energy, and in particular alternative, environmentally friendly car designs. The most accessible of these designs was the hybrid car, with working models already on the road. With their highly fuel efficient design, they deliver much of what they promise, but the hybrid picture is not entirely problem free.

Identification

A hybrid is any vehicle that uses two or more sources of power for propulsion. In cars, this most often refers to a hybrid electric vehicle (HEV), which relies on both an electric motor and an internal combustion engine. This is done in an effort to achieve greater fuel efficiency.

Considerations

Because most people think of an HEV when they think of the term "hybrid," they completely overlook entire swathes of other hybrid vehicles, some of which have been around for a long time. For example, the moped design that features both muscle-power pedaling and internal combustion engine power is a hybrid. The more modern electric bicycle does the same, only with a battery instead of a gas-fired engine.

Types

There are multiple models for HEV vehicles: petroleum fuel engine assistance; electric engine assistance; and plug-in hybrid electric vehicles (PHEV). The petroleum fuel assistance model of hybrid relies mainly on its internal combustion engine, with the electric motor being capable of only low speeds. Typically, this model will use the electric motor when idling, and then use it to accelerate up to about 20 or 25 mph. Then, the gasoline-powered engine will be automatically started and take over for providing propulsive power. The Toyota Prius is an example of this type of hybrid. The Electric Engine Assistance model of hybrid uses a lower power internal combustion engine, geared around maximum fuel efficiency. In order to achieve extra power for things like climbing hills or hard acceleration, the car has an electric motor which kicks in to provide the added power. Honda hybrids work on this principle. PHEV cars attempt to circumvent the limits on a purely electric, battery-driven car. They rely entirely on their batteries for motive power during the first several dozen miles of driving. When the battery is exhausted, the internal combustion engine on board is then used to either recharge the battery, or for a short trip to a recharging station.

Misconceptions

One of the most frequently cited "problems" with the hybrid design is actually misinformation. It is said that because the manufacture of the lithium ion or nickel batteries used in hybrids are so energy-intensive, at the end of the day a hybrid is actually less environmentally friendly than a conventional car with an internal combustion engine. At the time the car rolls off the assembly line, this is probably correct. However, this takes into account none of the emissions made by the respective vehicles after that. Taking into account carbon emissions made by the two vehicle types during their expected lifetimes, hybrids have substantially lower emissions than internal combustion engine cars, even taking into account the battery manufacture. There are, however, other problems involving the manufacture of the batteries for hybrid cars. All battery designs are at least moderately toxic, including the two types favored for hybrid cars. However, lithium ion and nickel battery designs are not even remotely as problematic as the lead-acid design that is the basis for every battery on the road in a conventional vehicle today. In reality, the only difference between the toxic pollution potential of a hybrid's battery and that of a standard car is a matter of size. The hybrid has a big, moderately toxic battery; the conventional car battery is smaller, but packed with lead.

Effects

Two immediate problems with hybrids are their lack of pick-up and their battery life. First, acceleration in hybrids is generally very poor, even if they are capable of a reasonable top speed. Second, the batteries degenerate faster than one is accustomed to with a standard car battery, and need to be replaced every 80,000 miles or less. These batteries cost several thousand dollars each. The most serious problem with hybrid designs are the manufacturing inputs for their high performance batteries and electric motors. They are very intensive in rare elements, which goes a long way to explaining their expense. Most of these elements currently come from China, and the supply as it exists today is not expected to last more than several years under even the most generous estimates. Efforts are underway to open new sources of these rare elements, but it is probable that they will not be producing in quantity before the existing supplies begin to dwindle and cause a shortage.