What's Charging the Charging Station?

Electric vehicle (EV) owners are often under the impression that they are “saving the earth” by using electricity instead of gas to power their car. What many do not realize, however, is that the source providing electricity to their charging station is most likely a fossil fuel. This is because a majority of the United States’ energy still comes from fossil fuels. Only 11% of the US’s energy comes from renewable resources, while the other 89% is from fossil fuels including petroleum, natural gas, nuclear electric power, and coal ( EIA ). As more cars continue to become electrified, it is important that we ask exactly how “eco-friendly” these vehicles are. Gas powered cars are responsible for releasing greenhouse gases at the back end- this refers to the oil being burned when powering individual cars. This “back-end” pollution produces black carbon which accounts for about 35% of global emissions. On the other hand, electric powered cars that receive their electricity from fossil fuels, are responsible for releasing greenhouse gases at the “front end”- this refers to fossil fuel combustion happening at the power plant. This front end pollution produces SO2, which accounts for about 73% of global emissions, and CO2, which accounts for about 25% of global emissions ( Requia ). The purpose of this project is to determine whether states are making true sustainable living more accessible. “True” meaning that EV owners can charge their cars using renewable energy and not just fossil fuels.

• Where in the US are electric vehicles being charged with renewable energy?
• Where in the US are most electric vehicle charging stations located and how does this compare to these states' total renewable energy use?

The general methods used for representing the following maps include the performance of a "Select by Attribute" query for maps 1 and 4 in order to create clear distinctions between fuel types. Maps 2 and 5 use EV station data normalized by population (per 100,000). Map 3 uses manual intervals for the graduation symbology so viewers can more clearly see states with particularly low renewable energy use. For more information on methods used for a specific map, refer to the analysis section below the map.

"Renewables" refer to: geothermal, solar, hydroelectric, wind, and biomass power.

"Fossil Fuels" refer to: petroleum, natural gas, coal, and nuclear power.

The above map (Map 1) shows the primary fuel type used for powering electricity in each state. If you're an EV owner in Washington, Oregon, Idaho, Montana, South Dakota, Vermont, or Maine... you're in luck! The electricity powering your EV comes from renewable energy. As for EV owners in the 43 other states, you are powering your EV with a fossil fuel- most likely natural gas or coal. Keep in mind, this map shows primary fuel type meaning this map does not show all fuel types that are being used to power your state's electricity, but rather, the fuel type with the highest percentage. So don't lose all hope, it's still possible that your EV may be powered with renewable energy... it's just less likely.

The above map (Map 2) shows the number of electric vehicle charging stations for each state- normalized by 2019 population. The ArcGIS field calculator tool was used to calculate normalization: (# EV Stations / Population) * 100,000. Normalization by population must be done in order to take into account that states with more residents have more cars, meaning more electric vehicles, and consequently more charging stations. States with the most charging stations are California, Oregon, Washington, Utah, Colorado, Massachusetts, Maine, and Vermont. Two of these states are particularly unique: California and Vermont. California is special since has significantly more EV charging stations than any other state- over 6,000 (this is why we normalize). Vermont is special since it has more EV charging stations per person than any other state despite its small population, with 39 EV charging stations per 100,000 people. This map's symbology uses Quantile data classification in order to emphasize the relative position of each state's number of stations.

In the above bar plot, you can take a closer look at exactly how many EV charging stations each state has as of December 2020.

Left: The above map (Map 3) shows percent of renewable energy use for all sectors (i.e. fuel used for other applications, not just electricity). States with the highest percentages of renewable energy use are Oregon, Washington, Idaho, South Dakota, Vermont, and Maine. This map's symbology uses manual intervals to emphasize how many states use less than 10% renewable energy.

Right: The above map (Map 4) shows primary fuel type used for all sectors. Only Oregon, Washington, South Dakota, and Iowa use primarily renewable energy as fuel for all sectors- the majority of states rely on petroleum.

The above bivariate map (Map 5) compares states' renewable energy use for all sectors to their number of EV charging stations (normalized by 2019 population.) States such as California, Oregon, Washington, Maine, and Vermont have higher renewable energy use and a higher number of EV charging stations. On the opposite side of the spectrum are states such as Texas, Louisiana, Mississippi, Illinois, Indiana, Ohio, Kentucky, West Virginia, Pennsylvania, and New Jersey, which have lower renewable energy use and a lower number of EV charging stations.

For my first spatial question, I was able to determine that the probability of an EV owner charging their car with renewable energy is most likely in Washington, Oregon, Idaho, Montana, South Dakota, Vermont, and Maine. Meaning that the 43 other states are primarily being powered by fossil fuels- overall, making electric vehicles not as eco-friendly as one might hope. As for my second spatial question, I was able to determine that most EV stations are located in California, Oregon, Washington, Utah, Colorado, Massachusetts, Maine, and Vermont. The renewable energy use for all of these states, besides Utah and Massachusetts, were exceptionally high. However, only in Oregon and Washington, is renewable energy also the state's primary fuel type- the rest of these states primarily rely on petroleum.

So, what's charging the charging station? The short answer is fossil fuels. Currently, our nation’s renewable energy use is far too low, meaning that the US still has a lot of work to do before EVs can become truly sustainable. But don't lose hope! This not all bad news- it's still important that we begin to implement the technology and infrastructure (such as charging stations) needed to support a more sustainable way of living. While fossil fuels are currently the primary fuel type powering the US, I am hopeful that it will not always be that way. As renewable energy becomes more prominent, people will soon be charging their EVs with stations that are powered by clean energy.

The lesson here for EV owners is: don't think that you are solving climate change by simply owning an electric vehicle.

• For errors in data, there is a possibility of data being incorrect for any of the energy datasets which showed primary fuel type or percent of renewable energy use since the values had to be hand typed into new excel sheets. I was particularly vigilant when transferring data, however, inaccuracies are not impossible. 
• As for errors in spatial analysis, there are several external factors that must be considered when interpreting the maps I created. Although the number of EV stations were normalized by population, there are a variety of other factors that may influence these numbers. These factors can include Tesla’s strategy for expansion, the average income of residents of that state, and the environmental concern of state residents. 
• When interpreting the spatial analysis errors for the energy maps, there are two key external factors that must be considered. One, is the reality that it’s not known exactly where certain types of fuels are going. While it’s helpful to look specifically at fuel use for the electricity sector, it’s not a solution; electricity fuel use can vary grid line to grid line, which means some EV stations might be getting their electricity from renewables, while others are getting it from coal. Finally, it also must be taken into account that EV owners often charge their car at home in addition to charging stations. This means that some EV owners may be living off-grid and could be charging their vehicle using renewable energy (such as solar) despite living in a fossil fuel dependent state. 

The default map projection of ArcGIS online is the Web Mercator coordinate system. This does not influence how my maps may be perceived.

Blomst. “Tesla Model X Charging Supercharger.” Pixabay, October 17, 2016.  https://pixabay.com/photos/tesla-tesla-model-x-charging-1738969/ .

Requia, Weeberb J., et al. “How Clean Are Electric Vehicles? Evidence-Based Review of the Effects of Electric Mobility on Air Pollutants, Greenhouse Gas Emissions and Human Health.” Atmospheric Environment, vol. 185, 2018, pp. 64–77.,  https://doi.org/10.1016/j.atmosenv.2018.04.040 .

“U.S. Energy Information Administration - EIA - Independent Statistics and Analysis.” Renewable Energy Explained - U.S. Energy Information Administration (EIA), 2019,  www.eia.gov/energyexplained/renewable-sources/ .

Population:

Aggregated from the following for 2019. US Census Bureau. “Table 1. Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2010 to July 1, 2019.”  https://www2.census.gov/programs-surveys/popest/tables/2010-2019/state/totals/nst-est2019-01.xlsx  (Accessed December 20, 2020). (link will download the dataset)

State Fuel Types- All Sectors:

Aggregated from the following State Profiles. Georgetown Climate Center. “Fuel Use.”  https://www.georgetownclimate.org/clean-energy/clean-energy-and-climate-data.html?state=AL  (Accessed December 20, 2020).

State Fuel Types- Electricity:

Aggregated from the following State Profiles. Georgetown Climate Center. “Sources of Electricity Produced in *State* in 2018 ”  https://www.georgetownclimate.org/clean-energy/clean-energy-and-climate-data.html?state=AL  (Accessed December 20, 2020).

Population:

Aggregated from the following for 2019. US Census Bureau. “Table 1. Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2010 to July 1, 2019.”  https://www2.census.gov/programs-surveys/popest/tables/2010-2019/state/totals/nst-est2019-01.xlsx  (Accessed December 20, 2020). (link will download the dataset)

Bar Plot

Ezeoha, Kathryn. "Number of Electric Vehicle Charging Stations by State." December 2020.

EV Charging Stations:

US Department of Energy. “Alternative Fueling Station Locator.” Selected filters: US, All Fuels, Access: Public, Status: Available.  https://afdc.energy.gov/stations/#/find/nearest?country=US  (Accessed December 20, 2020).