Vehicles powered by electricity come in several flavors; simple hybrids (HEV,) plug-in hybrids (PHEV,) and fully electric (EV.) Their biggest advantage is that vehicles powered somewhat or completely by electricity are more efficient. This means they are inherently less costly to operate.
Toyota has led the charge with the introduction of their hybrid Prius in 1997 in Japan and 2001 in the US and the rest of the world. It is basically a traditional Internal Combustion Engine (ICE) and drive train. It has a small battery and electric motor which provides supplemental power, increasing the efficiency of the vehicle, even though the battery is charged mainly by the ICE. Scores of cars now use this hybrid technology and even a few pick-ups.
A very important component to all these electric vehicles is regenerative braking. When the car decelerates it causes the alternator in the vehicle to become a charging device for the battery, in the process slowing the vehicle without using the brakes.
Intermediate between simple hybrids and fully electric are plug-in hybrids. They are different in that they are true electric vehicles with an ICE to extend the range. The drive train in these vehicles are powered by the electric motor, the ICE is just used as a generator. The PHEVs have a battery which gives the vehicle a range of about 40 to 50 miles, generally enough for the majority of commuters. The vehicle can then be plugged in at home to recharge the battery for the next day’s commute. For longer trips, the ICE charges the battery on the fly.
The ability to charge a battery-powered car from the grid, that is by plugging into a wall outlet creates considerable savings as the energy to power a vehicle by electricity costs one third to one quarter as much as the cost of gasoline. Another bonus is cleaner air. Electric power is inherently cleaner than ICE power because much of the energy used to produce the electricity is from clean sustainable sources such as wind, solar and hydropower.
The real future of surface transportation is all-electric cars. These vehicles take advantage of regenerative braking and other computer controlled mechanisms. The EPA rates EVs by comparing the electric energy used to the amount of gasoline an equivalent ICE car would use. It comes out to something like 130 miles per gallon equivalent or better. Although electric cars initial costs are higher, over the lifetime costs are frequently lower than ICE vehicles due to lower fuel and maintenance costs.
By far and away the best known electric vehicle is the Tesla, built by visionary Elon Musk. Depending on the model, Teslas have a range of between 250 to over 300 miles on a charge. More importantly for Tesla however is the fact that a fast charging network has been built out across the US such that travel, at least on interstate highways, not a problem. The Tesla charge stations are located so that a 200 to 300 mile drive get one to the next charger. Charge times to fill the battery are on the order of an hour or less.
Dr. Bob Allen, Ph.D., is Emeritus Professor of Chemistry at Arkansas Tech University.