Analysis of Electric Vehicle Charging

Station Along US I-40

Colby Butcher- Christian Academy of Knoxville

Jack Baldwin- L&N STEM Academy

Abstract -- Electric vehicles (EVs) are just now starting to become more popular.

These vehicles aim to cut down on emissions while providing a practical vehicle

with high cost efficiency. The goal of this study is to examine the current network

of EVs and charging stations and provide suggestions to aid further development

if it is seen necessary. We are looking at a specific segment of interstate to

narrow our research and for simplification. We found that installing chargers at

rest areas along the interstate will make long distance EV travel possible and

easier.

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Introduction

Electric vehicles are not a new technology, but they are a growing technology

and the existing infrastructure is questioned as whether it will support future growth.

There are more than 30,000 electric vehicle chargers across the United States that are

mostly in metropolitan areas, coastal areas, and conservative, environmentally friendly

areas. Aside from being inconvenient, many chargers use older technology that takes

several hours to reach almost a full charge. One of the major reasons this needs to be

addressed is that many people want to be environmentally friendly, but their vehicles

lack of charging support on their desired travel route does not currently work for them.

The main issue with the current electric vehicle (EV) charging network is that it does not

allocate long distance travel, especially in rural areas. By examining the locations and

charger types of the existing system and using a geoprocessing software, ArcGIS, to

investigate the sufficiency of these charging station locations, it is possible to suggest

ideas that may improve the EV market.

Literature Review

One of the first aspects of EVs that was studied were the differences on the

consumer level. Various EV manufacturer websites show that full battery electric

vehicles (BEVs) have many differences from plug-in hybrid electric vehicles (PHEVs).

One important difference is that, typically, BEVs have significantly less range (around

100 miles) than PHEVs (usually more than 200 miles). The PHEVs hold the advantage

of having an alternative internal combustion engine to extend range by providing power

to the drivetrain, and in some cases, to recharge the batteries for the electric motor.

Another difference is that BEVs typically cost less because of the simplicity. Hybrids

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cost more, in most cases, because of complexity and also because there are more

models that are from luxury car brands such as Lexus, or other similar brands.

Currently, BEVs are for short range excursions. Only a few models have the capability

to make medium to long distance travel. Hybrids are for the people who want to be

environmentally friendly, but still need to make long trips.

Figure 1: BEV (left) and PHEV (right) image from “Electric Cars”

One of the next aspects studied about EVs was the charging times of different

vehicles and chargers. The main idea is that there are four types of EV chargers, types

1-4. Kristen Hall writes about the different types of chargers and their differences. A

type 1 charger is a 110V or sometimes 220V charger cable that plugs directly into the

wall. This type of charger can take up to 20 hours to full charge a vehicle (Hall). A type 2

charger is a significant upgrade allowing for charge times of less than 8 hours

depending on the desired charge percentage (Hall). Many EV owners may not charge

their cars to 100 percent because the last 20 percent charge can take the same time as

the first 80 percent; this is true will most batteries, not just car batteries (Zach). Type 3

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and type 4 chargers are classified as DC fast chargers. These chargers allow for much

more rapid charging at the sake of long term battery life. The batteries may start to

malfunction, and they will need to be replaced at the owner's expense.

Charging costs are just as important as charging speed. Charging cost can vary

greatly, much more so than gasoline. While gasoline may fluctuate more over a long

term, electricity rates fluctuate daily by pretty high percentages. Different locations will

also have different electricity rates. This has a lot to due with how rural an area is. Rural

or remote areas often have more expensive electricity (Lachnit). Even with fluctuations,

the cost of charging an EV is still in the single digits. For a car with a range of around

100 miles and that is charged in a urban or suburban area, the charging cost could be

just a few dollars. Hawaii has some of the most expensive electricity rates. At these

rates and current gas prices, a gas car would need to get around 40mpg to match the

cost of electricity for an EV (Lachnit). Overall, the BEV is superior in cost efficiency in

almost every case when compared to gas vehicles; the only drawback is range and

charging time. The cost of ownership of EVs has been going down as the technology

advances. One of the key things that keeps costs down is that batteries do not have to

Figure 2: Type 1 charger (left), DC fast charger in Knoxville (right)

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be replaced as much as they used too, and since batteries are expensive, it cuts cost

significantly

Figure 3: Top 5 EV data from (“Monthly”) and corresponding automotive manufacturer websites

Tesla makes the best electric vehicle in virtually all aspects; you get what you

pay for. They have a much better range than any other EVs currently on the road. The

tesla models also are much more luxurious as to be expected and have the most

comfort and safety features. The Nissan leaf is the most popular EV because of its

practicality and lower price.

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To compare the top five EVs, we divided the new price of the car by the full

charge range to get an approximate “cost/range” value. This chart shows that although

the Tesla cost more, it is comparable to the leaf as far as the range you get compared

to the price. Double the price gets about double the range along with many other

features. The hybrids obviously have a much larger value because of their longer

ranges, but comparing them directly with BEVs is not practical.

We also researched the usage of EVs in the US. California and Washington have

both the highest number of EVs and the highest percentage. This is partially due to the

large population in these states. These states also have some legislation that has been

put in place to increase EV usage. Perhaps the largest reason that EV usage is higher

in these areas is because they are typically more conservative and environmentally

friendly.

Figure 4: EV density map(Gallucci)

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One of the last things that we looked at for background information of EVs is the

benefits that the purchaser gets from the government or other agencies. The most

prominent benefit is a $7,500 tax credit for purchasing new BEVs (“Federal”). PHEVs

can get up to $5,000 in tax credit (“Federal”). Some power companies also have rebates

for buying charging stations from them that can be up to $1,000 (Berman). Some states

also offer unlimited high occupancy vehicle (HOV) lane passes even if there is only one

person is in the car (Berman). Most benefits offered are for the first owner of the car

only. While buying a used car is cheaper, buying a new one might be more practical in

some cases due to the rebates and tax credits.

Method

The first element of the methodology was to determine a route, or segment of

roadway, to focus our study. I-40 from Knoxville, TN to Barstow, CA was the route of

study. This route was chosen because it represents a long distance trip that most

electric vehicles would currently struggle to complete.

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Keeping this route in mind, we started to learn how to use ArcMap. ArcMap is a

mapping software included in ArcGIS that allows the user to download maps and

overlay data or other elements. We downloaded the overlay needed to represent the

United States on the correct coordinate system to match our charging station data. Next

we began to add our charging station data from excel. We narrowed the data down to

just I-40 and separated it into private and public stations. At this point, there appears to

be some large gaps in the route.

Figure 5: US I-40 public and private charging stations (made with ArcMap)

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Next, the data was classified further into stations usable for only for Nissan, only

for Tesla, and truly public chargers. The reason we did this is that some of the public

stations were only available to Nissan of Tesla. If we left all the stations as public, it

would show an impossible route for most BEVs.

Figure 6: US I-40 charging stations further classified (made with ArcMap)

Results

Our results consisted of two maps that show the difference before and after we

added rest stops as possible recharging areas. Currently, most rest stops do not have

EV chargers. Adding chargers to rest stops eliminates many of the range gaps that

different types of cars have. Rest stops are good compared to truck stops or other areas

because there is plenty of space to hang out and relax while the car is charging.

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Figure 7-9: Representation of adding charging stations to rest areas

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Discussion

In our results, adding chargers at rest stops make route possible and much

easier. There are still a few gaps in the western US, but they could be filled by adding

stations to public parks or some other area easily accessible from the interstate. As

expected, Tesla owners will encounter the least problems when it comes to long

distance travel. Nissan seems to be the next best, then all other cars with standard

chargers. This data could further be studied by looking at what types of chargers are at

current charging stations and the time it would take to travel the route before and after

the addition of DC fast chargers.

Conclusion

To implement the charging stations on I-40, we suggest installing 2 to 4 DC fast

charging stations. 2 to 4 should be enough with the current EV market, but it will still

allow for some growth because the chargers that are in place now, while not convenient

for long distance travel, are not being used a lot of the time.

As with all growth in technology, funding has to come from somewhere. One idea

is that city or state governments could provide some funding in hopes of increasing

tourism and travel. Automotive manufactures could also consider providing funding to

increase sales. The chargers could also have a small fee to make the money back from

the cost. We estimate that 4 DC fast chargers at rest stops on I-40 would cost around

$2,000,000, and for all US rest areas it would be over $120,000,000. More research

would need to be done to prove this as a viable, cost-efficient, option, but with our

research it seems that it would be a good option and prompt industry growth.

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Acknowledgements

Special thanks to Alexandra Boggs, Dr. Chien-fei Chen, Kay Boakye, Dr. Shashi

Nambisan, and Mr. Erin Wills

This work was supported in part by the Engineering Research Center

Program of the National Science Foundation and the Department of Energy

under NSF Award Number EEC-1041877 and the CURENT Industry Partnership

Program.

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References

Works Cited

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