Blog Discussion: The US Energy Flow Super Sankey

The visualization on the site shows a Sankey diagram that maps out how energy moves throughout the United States. A Sankey diagram is a type of chart that uses the width of connecting lines to show how much energy is flowing from one stage to another. In this case, it shows where our energy comes from, how it is transformed, where it gets used, and how much is lost along the way.

The diagram starts with the different energy sources such as natural gas, coal, oil, solar, wind, nuclear and hydro. These connect to different systems that convert energy such as power plants and fuel refining. From there, the flows move toward end-use sectors like transportation, homes, industry and commercial buildings. One of the most striking things shown in the Sankey is how much energy is lost or wasted during conversion and transmission. The wasted energy appears as very large flow bands which shows how inefficient parts of the system are.

What the Sankey Does Well

• Shows the big picture of the entire US energy system all at once
  
  

• Displays scale clearly because wider flows immediately show what uses the most energy
  
  

• Reveals inefficiencies by showing how much energy never reaches meaningful use
  
  

• Helps identify where change would matter most, for example improving vehicle efficiency or power plant performance
  
  

This type of diagram helps us understand that the energy system is not just simple input and output. There are many pathways, steps and losses. It allows a viewer to see how complex the system truly is.

Challenges and Limitations

• It is hard to read unless it is viewed very large because there are many lines and labels
  
  

• It can be overwhelming for new learners because everything is shown in one place
  
  

• It only shows one moment in time and does not show how energy use has changed year to year
  
  

• Tracing a single flow can be confusing when lines cross or weave together
  
  

The Sankey format is strong for showing flow size and direction, but it can become too dense if there is too much information shown at once.

Possible Alternatives or Improvements

• A simplified Sankey that shows only a few major flows for general audiences
  
  

• A zoom-in Sankey for each sector such as transportation or home energy use
  
  

• A time-based animation that shows how energy sources have changed over decades
  
  

• A treemap or pie diagram for showing which parts of society use the most energy, without focusing on the flow process
  
  

Final Thoughts

The Sankey visualization is a powerful way to represent how energy moves and where it gets wasted. It makes clear that a large amount of energy never becomes useful work and is lost as heat or inefficiency. However, the amount of detail can be overwhelming if the viewer does not have guidance. For a complete understanding of the US energy system, the Sankey should ideally be paired with simpler supporting visuals and explanations.

Overall, the Sankey diagram is a strong tool for professionals and researchers, but it benefits from breakdowns and simplification when presenting to wider audiences.