Visualizing Efficiency: How Sankey Charts Illuminate Flows and Transfers

Sankey diagrams, named after Irish Captain Matthew P. Sankey who first applied them to the visualization of water flow, have become an invaluable tool in various fields for illustrating the flow and transfer of energy, resources, or any type of material. This graphical representation method is particularly useful in contexts where understanding the efficiency and distribution of resources, such as water, energy, or economic transactions, is crucial. In this article, we’ll explore the creation of Sankey diagrams, their applications, and how they effectively illuminate the flows and transfers that are often challenging to visualize otherwise.

Understanding the Basics of Sankey Diagrams

A Sankey diagram displays flowing quantities, usually with the width of the flow proportional to the quantity. In the context of renewable energy, it can illustrate the distribution of energy as it moves through various systems or components, highlighting losses and efficiencies along the way. In environmental studies, they can represent the flow of materials through ecosystems or industrial processes. Regardless of the context, the key elements of a Sankey diagram include:

I-Nodes (Inputs): These mark the beginning of the flow, representing where a resource enters a system or process.
O-Nodes (Outputs): These indicate the end points of the flow, showing where resources or materials exit the system.
Connecting Flows: These are the lines that represent the flow of resources or materials between the inputs and outputs, with their width or thickness representing the amount of flow.

How to Create a Sankey Diagram

Creating a Sankey diagram can be relatively straightforward, particularly with the help of data visualization tools. Here are some steps to guide you through the process:

Gather Your Data: Start by collecting the data you need, which should include quantities and the source or destination for each flow. This data can be structured in a spreadsheet or database format.
Organize Your Data Correctly: Ensure your data is organized in a way that makes sense for a Sankey diagram. Typically, you’ll need columns for the source, destination, and the quantity of the flow.
Choose a Tool: Many tools and software packages are available for creating Sankey diagrams, including R, Python (with libraries such as matplotlib, seaborn, or plotly), Tableau, and specialized Sankey diagramming tools like Tableau or the free tool NetworkDx.
Apply Your Data: Import or input your data into the chosen tool. Most tools will allow you to customize the aesthetics and the appearance of the chart to best represent your data.
Adjust Widths and Angles: The width of each flow represents the quantity of material, energy, or data flowing through it. Adjusting the widths based on the data’s proportions is essential for clarity and for the reader to understand the significance of each flow. The angles and the number of flows can also be adjusted to ensure that the diagram remains as clear and uncluttered as possible.

Applications of Sankey Diagrams

Sankey diagrams are versatile and have found applications in diverse fields. Here are some key applications:

Renewable Energy Studies: They help in visualizing and assessing the efficiency of energy conversion processes, from the input of renewable energy (solar, wind) to the end-use electricity.
Ecological Studies: Ecologists use them to model the flow of energy or materials through ecosystems, helping in the study of trophic levels and ecological efficiency.
Industrial Processes: Manufacturers use Sankey diagrams to understand the flow of materials, energy, and waste in their processes, optimizing processes for efficiency and sustainability.
Economic Data Visualization: They are also used in economic studies, showing the flow of economic transactions, trade flows, or even the distribution of wealth.

Conclusion

Sankey diagrams are a powerful tool for illuminating flows and transfers, offering a clear visual representation of how resources move through a system or process. Whether tracking energy efficiency, understanding ecological cycles, or optimizing industrial processes, Sankey diagrams can reveal intricate patterns and highlight areas of efficiency or potential for improvement. With the right tool and data, anyone can create a Sankey diagram to effectively communicate complex flows and transfers.

SankeyMaster

SankeyMaster is your go-to tool for creating complex Sankey charts . Easily enter data and create Sankey charts that accurately reveal intricate data relationships.