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57 required for EVs and considers the potential for using smart Charge station: Charge stations can be classified into charging software to upload vehicle information and assign levels based on voltage supply such as those shown in user fees. Table 18. The amount of charging time is closely asso- ciated with the voltage of the available electricity sup- 3.4.1 Objectives of Using Electric Cars ply. Figures 33 and 34 show two examples of designs for charging electric cars. The charging post shown in Two objectives of using electric cars are (i) reducing emis- Figure 33 is designed by Electric Transportation Engi- sions from gasoline cars and improving the environment, and neering Corp. (eTec) for charging the Nissan LEAF, while (ii) reducing global dependence on petroleum. A study on Figure 34 demonstrates the design by Better Place, Inc. greenhouse gas (GHG) emission released by Pew Center The eTec company plans to install more than 10,000 (Greene and Schafer, 2003) indicates that transportation is the Level 2 charge stations in five states: Arizona, California, second largest source for GHG emissions both in terms of the Oregon, Tennessee, and Washington. volume and rate of growth. By 2020, the transportation sector Charge at home: A typical household in the United States alone will be responsible for 36% of total CO2 emissions. The has electric outlets of 1.5 kW (with 110 volt supply). Those second objective has implications for U.S. national defense in other countries may have outlets of 3 kW (with 220/ interests and economic independence. 240 volt supply). Charge times are reduced when higher power levels of electricity are available. However, it is 3.4.2 Technology Components likely that nearly all homes will require special wiring to Related to Electric Cars receive the higher power levels needed for quick recharge of electric cars. Key technical issues for electric cars are charging, recharg- Switching station: Instead of charging batteries, an alterna- ing, and replacing batteries. To gain public acceptance and tive design is to switch or exchange depleted batteries. Bat- support, the charging or replacing of batteries in electric cars teries can be bought, leased, or replaced under a subscribed requires infrastructure for charging a car, preferably taking contract. little more time than is required to refuel a gasoline-powered Cars: Electric cars such as the LEAF, plug-in hybrid electric car. Technological components related to charging electric vehicle (PHEVs), or hybrid cars could be designed to work cars are batteries, a charge station, a switching station, and with charging and switching stations. the electric car itself. Below is the description of each techni- cal component: 3.4.3 Electric Vehicle Implications Battery: Several different types of batteries have been used for Revenue Collection in electric cars, such as Lithium-ion batteries, which provide 200 to 300 miles per To the extent that electric vehicles are embraced by con- charge. sumers, they could lead a revolution not only in how vehi- Lead-acid batteries, which provide up to 80 miles per cles are powered but also in the way that highways are funded. charge. When vehicle charging profiles are matched with periods of Nickel-metal hydride (NiMH) batteries, which have low demand, the existing grid could support a large transi- higher energy density and may offer 120 miles per charge. tion towards plug-in vehicles. In fact, the results of a study Charge station (or charge at home): Charging batteries is recently conducted by the Pacific Northwest National Labo- one of the most challenging technical requirements of elec- ratory (PNNL) suggest that existing electricity generation tric cars. and transmission infrastructure has the technical capacity to Table 18. Levels of chargers and charge time needed for electric cars. Charge Time for Charge Time for Plug-in Level of Charger Electric Cars Hybrid Electric Cars Level 1 (110V) 8 to14 hours 4 to 8 hours Level 2 (220240V) 4 to 8 hours 2 to 4 hours Level 3 (480V)(*) 15 minutes 15 minutes (*) Level 3 uses a mint-charge technology. Source: Electric Transportation Engineering Corp.