Friday, April 05, 2013

Smart Car Chutzpah and the Efficiency of Electric Cars


Drive a Smart car, and you start thinking you can park just about anywhere. This one's clever, if not legal. More frequent sightings in recent weeks may be by chance, or may mean they're becoming more popular. An older post (How  to Parallel Park in a Parallel Universe) shows how Smart cars fit into tight spaces in Rome, Italy.

A check of gas mileage ratings reveals that Smart cars, despite their small size, get only 36 mpg combined city/highway--less than the Prius station wagon. The ratings also show the tremendous efficiency advantage of electric vehicles, nearly all of which get more than 100 mpg equivalent. The electric Smart car is four times more efficient than its gasoline-powered counterpart for city travel, and a little less than three times as efficient on the highway. Though electricity is very inefficient for resistance heating (e.g. electric dryers, water heaters, etc), it is very efficient at turning energy into motion (e.g. electric cars).

A washing machine is an example of an appliance that both uses electricity efficiently (the motor that spins the tub) and inefficiently (heating the water). Since effective cold water detergents have been developed, one can dispense with the inefficient water heating component. 


Electric or hybrid cars are also handy when one gets caught in a traffic jam or a line, such as awaiting an inspection. There's no need to keep the engine idling, because in hybrids it automatically turns off.

Of course, in comparing the efficiency of electric and gasoline-powered cars, one has to compare how much energy was used, and pollution produced, in the process of generating and delivering the electricity and the gasoline. If one gets an electric car and then buys renewable electricity for the home from a supplier like North American Energy, it's possible to shift dramatically away from dependence on fossil fuels. Prices for 100% renewable energy appear to be competitive with what PSEG is currently charging for nonrenewable.






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