Sankey Diagram

 Sankey Diagram 

    By; Halle Richard 

    A Sankey Diagram is a type of flow diagram where the width of the connection lines is proportional to the flow quantity. It makes it useful for visualizing how a resource moves through a process or in this case how U.S. energy flows. These diagrams can help explain complex processes, highlight significant factors and show losses or efficiencies. Sankey diagrams are beneficial since they simplify complex data by visualizing the flow of quantities which makes it easier to identify major transfers and patterns. These diagrams are powerful for decision-making in areas such as energy analysis. 

Taking a first glance at this diagram, I was very lost. It looked like text thrown onto a graph with many colored lines. I was unsure what I was looking at when I saw it. But with further reading I was able to see that the diagram represents all of the energy flows in the U.S. economy from primary energy sources such as coal, natural gas, oil, hydropower, solar, geothermal and nuclear power through their transformation into intermediate sources such as gasoline, diesel and other intermediate fossil fuels. The interactive graph gives more data of each variable as well. I think the Sankey diagram was a good tool choice to display this data. An alternative option could be a tree map. The data in this case would be displayed as a set of nested rectangles, where the area of each rectangle is proportional to it's value.