In The New York Times, Nadja Popovich explores how each state has sourced their electricity from 2001 to 2017. A common theme that has surfaced is the dramatic increase in popularity of natural gas over coal, making it the new leading power source for electricity (Popovich, 2018). While renewables have also become more prevalent, the wide range of energy sources available creates a variety of mixes for each state to use. Before highlighting each state’s history, Popovich, on the behalf of experts in the field, writes that switching to natural gas as our leading energy source cannot be enough to reverse the effects of global warming (Popovich, 2018).

Until around 2015, close to half of the country’s electricity generation had largely relied on coal (Popovich, 2018). With a surging increase, natural gas has grown from seventeen percent of electricity generation in 2001 to thirty-two percent in 2018. This tops coal’s contribution of thirty percent as recorded in 2018 (Popovich, 2018). Nuclear energy and hydroelectricity have remained stagnant around twenty percent and seven percent, respectively, while wind has strongly prevailed since 2005 to be about six percent of our electricity generation today (Popovich, 2018). Comparing these statistics to Oregon, it’s interesting to see how different the state is compared to its country. The majority of Oregon’s energy source (around sixty-one percent in 2017) is provided by hydroelectricity, whereas coal only generated less than ten percent of electricity in the same year (Popovich, 2018). But similar to the rest of the country, natural gas use has increased over time, now contributing about twenty-four percent to electricity generation (Popovich, 2018).

The U.S. Energy Information Administration provided the data set, “Net Generation by State by Type of Producer by Energy Source”, used to create the visualizations in this project. They have recorded the statistics included since 1990, consisting of annual reports on every energy source for each state and the amount of megawatt hours generated from each source.

The first visualization, “Oregon’s Energy Source Generation Rankings”, looks at the top ten sources that provide electricity in the state of Oregon in the form of a bump chart. The rankings were measured by calculating the sum of each source’s electricity generation for each year. In this case, the variables would be each type of power source. As shown, hydroelectricity has been the dominant form of electricity generation for the past thirty years, while natural gas had made a steady increase through the 1990s to now be the second most popular energy source. Wind has had a very steep increase in electricity generation since 1990, while coal, wood, and other biomass follow behind at a consistent ranking. Solar was recently introduced in 2011 but has also made a very big jump in usage to now be the sixth largest source, slightly edging out other biomass. Geothermal, crude oil (or petroleum), and the remaining sources complete the list. It’s also important to note that nuclear energy was the second and third largest source from 1990-1992, but then dropped down to seventh the following year to now being completely out of the top ten.

The concept of ordinality can be shown in the bump chart, but it’s also important to note its differences with cardinality. Cardinality is focused on naming and differentiating between items, with no regard to ordering, while ordinality does consider the ordering of items (“Cardinality”). Since we’re looking at how these sources are ranked, order does matter, which means ordinality is shown.

The second visualization, “Oregon’s Energy Source Mix Over Time,” displays the percentage of each energy source’s electricity generation relative to the total amount produced each year. In this chart, since order does not matter and we’re comparing items relative to each other, cardinality is shown rather than ordinality. Once again, the variables being analyzed are the types of energy sources, while the measures used are the sums of each source’s generation converted to a percentage over the total. Consistent with the bump chart, hydroelectricity is the dominant power source since 1990, while natural gas is second, followed by wind power and other sources. This chart also shows the sudden increase in natural gas and wind power generation over time.

The third visualization is simply the legend in the upper right corner of the dashboard. The colors correspond to the colors of each energy source (the “variables”) in the bump chart, and were structured as a bubble chart. In Tableau Public, the audience are able to hover over each ‘bubble’ and see the corresponding source highlighted in the bump chart.  

As mentioned, wind and solar power has been tremendously growing in Oregon recently. Part of this could be due to the state’s Renewable Portfolio Standard adopted in 2007 (“Energy in Oregon”). This policy changed in 2016, now requiring that Oregon’s electricity generation be sourced by fifty percent of renewables by 2040 (“Energy in Oregon”).

Class lectures have been very consistent with the findings presented in these visualizations. But, these visualizations don’t explain so much “why” certain resources are being utilized much more now. As Dr. Wooten mentioned, one of the main reasons there was a surge in natural gas usage was because of how cheap it is now. Also, with companies trying to be more sustainable, they are more focused on lowering carbon emissions, leading to a lower utilization in coal. The speakers at the steam plant center also confirmed the lower prices and urge to become a more sustainable campus through renewable resources.

​

​

References​

Energy in Oregon. (n.d.). Retrieved February 26, 2020, from https://www.oregon.gov/energy/energy-oregon/Pages/Renewable-Portfolio-Standard.aspx

Cardinality vs. Ordinality. (n.d.). Retrieved February 26, 2020, from http://www.4dsolutions.net/ocn/cardinality.html

Net Generation by State by Type of Producer by Energy Source. [Data set]. US Energy Information Administration.

Popovich, N. (2018, December 24). How Does Your State Make Electricity? Retrieved February 26, 2020, from https://www.nytimes.com/interactive/2018/12/24/climate/how-electricity-generation-changed-in-your-state.html