Eleven hub charging locations were selected in the preliminary design. The locations were based upon AADT (shown in Table 4), proximity to highway, proximity to major elevation change, and user convenience (close to other attractions).
However, assuming all BEV owners fully charge their vehicle every night, this many public charging locations would be an over design for the small number of vehicles with their large in city range. Nissan claims a home Level II EVSE will be all a user will need for in city daily driving commutes. Nissan will also be installing three Level II EVSE and a DC fast charger at dealerships where LEAFs are sold in order to recharge their inventory (8). Current LEAF owners will be allowed to use this EVSE at no cost to them (Hours of dealership EVSE availability unknown). Chattanooga has two Nissan Dealerships that will install EVSE: Mountain View Nissan (Highway 27 Market St exit) and Hunt Nissan (Highway 153 Shallowford exit). The dealership EVSE will not consist of eTec brand EVSE; instead they will be Nissan’s Aerovironment brand.
The eTec brand EVSE, which will collect data for The EV Project, will need to be placed along the corridor (I-24, I-40, and I-75) of Chattanooga, Nashville, and Knoxville. At least two DC fast chargers will be needed every 30-40 miles of interstate (depending on elevation change) and must be accessible to both directions of travel (on interstate exit). Table 5 lists the placement of I-24 charging locations, Table 6 lists the placement of I-40 charging locations, and Table 7 lists the placement of I-75 charging locations.
The data above states that there must be at least nine DC Fast Charging locations on the corridors between Chattanooga, Nashville, and Knoxville. There must be two at each location to accommodate multiple EV drivers. Figure 38 shows the placement of the interstate fast chargers.
Since the Nissan LEAF can travel between 50 miles and 75 miles in Chattanooga on a single charge and the two Nissan dealerships in Chattanooga will be equipped with EVSE, there are no mandatory locations for charging hubs. This means that even without public charging locations, LEAF users who travel less than 50 miles a day should not feel any range anxiety as long as they start each day with a full charge. Therefore, it is recommended to eTec to place the DC fast chargers at accessible locations that are also the most attractive locations in the city in order to collect the most data and to increase popularity of electric vehicles. These locations in Chattanooga are site 8 Hamilton Place Mall, site 4 Northgate Mall, site 2 Highway 27 below Signal Mountain and site 11 downtown area. Figure 39 show the four hub site location and the Nissan dealerships.
Figure 39: Show the placement of hub location and Nissan dealerships
eTec and TVA stated that Tennessee should receive 50-60 DC fast chargers, 1200 commercial Level II EVSE, and 1000 residential Level II EVSE (all eTec brand EVSE) (17). If eighteen DC fast chargers are dedicated for highway corridor use, then that leaves 10-14 fast chargers per major Tennessee City participating in The EV Project. Therefore, it is recommended that each Chattanooga Fast Charging Hub location be equipped with four DC fast chargers. Also, in order to support older PHEV, which do not have a DC fast charging connection, the hub locations should have two Level II EVSE.
TVA announced they are developing solar-battery powered DC fast chargers to be placed in a highly visible location (17). It is recommended that this solar DC fast charging hub be placed in the downtown location.
In addition to the solar chargers, TVA plans on implementing 125 parking spaces with commercial Level II EVSE (17). For the remaining eTec brand commercial Level II EVSE available to Chattanooga. It is recommended that eTec advertise the EVSE to local businesses so that business can offer a free charge as an incentive to its EV customers.