In 1898, Matthew Henry Phineas Riall Sankey developed the Sankey Diagram when he wanted to visualize the energy efficiency of a steam engine. Since then, Sankey diagrams have been used in many different ways across various fields of study to show flow over time between stations. For example, in the webpage titled, “What You Need To Know About Energy” by The National Academies of Sciences Engineering and Medicine, the Sankey diagram is used multiple times to visualize the flow of energy sources throughout the United States and in specific states such as California.

While this may seem very complex at first, it is really not too bad and it effectively visualizes the distribution of energy sources to their respective industries in 2014. It is very interesting to see how important the traditional oil, coal, and natural gas industries still are despite the large pushes towards renewable energies such as solar, wind, and hydro.

Another interesting thing I found on this site is the breakdown and visualization of CO2 emissions from each energy source. Of the nine energy sources, only three contribute to all of the U.S. CO2 emissions. They include, oil (43%), coal (29%), and natural gas (28%). This helps the viewer see and understand how the largest sources of energy are also the largest contributors of carbon dioxide emissions despite the “cleaner” alternatives that are available.

This Sankey diagram looks very similar to the first one but it is slightly different and covers the regional energy system of Maryland, Ohio, Pennsylvania, and West Virginia. In this diagram, it visualizes imports and exports as well as the general energy usage. You can see how the imported energy sources come in on the left and how they are distributed across the grid. It is also important to note how much energy is exported from this region through sources such as coal and natural gas. This is clearly shown from the divergence of these channels that contribute to almost 404 Trillion British Thermal Units of exported energy.

Overall, this is a very informative website that has great examples of effective uses of Sankey diagrams. There is a lot of good information about the energy systems of the United States but also more specific data on related topics such as energy efficiency and the pros and cons of different forms of lighting.