Visualizing Energy Flows: A Creative Guide to Crafting Sankey Charts

Sankey diagrams, named after Mark L. Sankey who used them to describe water flow, are a popular tool for visualizing the flow of energy, materials, or people through systems. These diagrams are particularly useful for complex networks, energy systems, and supply chains. By visually depicting the amounts flowing from one group to another, Sankey diagrams help stakeholders in business and academia to understand, analyze, and communicate complex flows in a simple, accessible manner. In this article, we’ll guide you through the creative process of crafting a Sankey chart, covering its components, how to prepare your data, and best practices for effective visualization.

Understanding Your Data

Before you start creating your Sankey chart, ensure you have a clear understanding of your data and its flow. Define the beginning and the end of your system – this is your source and destination. For energy systems, for example, you might start with energy inputs from natural resources like coal or oil, and end with energy outputs for electricity, heat, or other forms. You’ll need to break down the flow of your data into several channels, each representing a step or category of your system. This will help create a clearer, more interpretable Sankey diagram.

Preparing Your Data

After you’ve defined your data flow, it’s time to prepare your data. Sankey diagrams require precise values for each step of the process, typically in a table that looks something like this:

Make sure your data is accurate and consistent. If your data represents an energy flow, ensure the energy values are in joules or a similar unit of energy. Remember, Sankey diagrams are a sophisticated tool for visualization, and the precision of your data will directly affect the clarity of your visualization.

Crafting Your Sankey Diagram

Choose Your Tools: There are several tools and software available for creating Sankey diagrams, from spreadsheet programs like Microsoft Excel to dedicated visualization tools like Tableau and Python libraries like Plotly or Bokeh. Choose the right tool based on your level of expertise and the complexity of your data.
Set Up Your Layout: Decide on the layout of your Sankey diagram. Traditionally, they have an elongated, or vertical layout, with the flow emanating from a lower source up to an upper destination. However, you can also use a horizontal layout or experiment with custom orientations and layouts to better communicate your message.
Categorize Your Data: Define the categories or steps for your Sankey diagram. These categories should be clear and convey the essence of your data flow. For energy systems, categories might include different fuels (coal, oil, natural gas), different types of energy outputs (electricity, heat), and intermediary steps (steam, chemicals).
Align Your Elements: Once your data is input, align your bars (or lines) across your diagram. This step requires some creativity; ensure that elements flow logically and are positioned in a way that communicates the flow of your data most effectively. The key is to optimize readability, so make sure there’s enough space between elements and that the most significant flows are emphasized.
Add Color and Text: Use color to highlight important flows or different parts of your system. For example, using a different color for renewable and non-renewable energy sources can help communicate your message more clearly. Add text labels to each step and flow, including descriptions, titles, and data values. Include a legend to clarify what each color or category represents.

Best Practices for Effective Visuals

Simplicity: Keep your Sankey diagram as simple as possible. Focus on conveying the data flow and avoid unnecessary details that clutter your diagram.
Data Clarity: Ensure that your data is precise and interpretable. Use a clear scale or legend to help viewers understand the magnitude of each flow.
Context: Provide context for your Sankey diagram. Add descriptions or brief explanations about the system, the source, and the destination. This helps audience members understand the bigger picture.
Interactive Elements: Consider making your Sankey diagram interactive. Many tools allow you to label individual bars or flows, enhancing readability and encouraging audience engagement.

Crafting a visually compelling Sankey diagram takes time, creativity, and attention to detail. By following these steps and best practices, you can create powerful visual tools that effectively communicate complex data flows. Sankey diagrams are a versatile tool for energy analysts, business professionals, and researchers, and their power lies in their ability to break down complex systems into understandable visual narratives. With practice, you’ll find that Sankey diagrams provide exciting opportunities for storytelling and analysis, making them a valuable addition to your data visualization toolkit.

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.