Streamline Sustainability: Decoding the Art of Sankey Charts

In an era where sustainability is paramount, data visualization has become a pivotal tool for informing, engaging, and catalyzing change. Enter the Sankey diagram, a unique graphical method for displaying the quantified flow of materials, energy, or cost through a process system. Sankey charts offer a clear, visual means of understanding complex systems at a glance, making them valuable for sectors ranging from sustainability to energy efficiency to financial flows. This article dives into the creation and applications of Sankey charts in the quest for streamlined sustainability.

The birth of Sankey diagrams

Sankey diagrams were first developed by a British mechanical engineer, William Playfair, but it was Max Schulze who refined the diagrams in 1898 with the introduction of his “Sankey-Sonde,” a device used in steam engine efficiency measurement. Sankey diagrams are named after him.

Decoding Sankey charts: Structure and Elements

A Sankey chart is typically represented as a set of parallel arrows with varying widths. Here are the key elements:

• Source and Sink: The source represents the entry of energy or material into the system, and the sink is where the flow exits the system. These are usually placed at the top and bottom of the chart.
• Arrows/Diagrams: These represent the flow of energy, materials, or costs. The width of each arrow indicates the magnitude of flow, which makes sense because more important processes are often represented by wider arrows.
• Labels: They indicate what each arrow represents with terms like ‘energy’ or ‘materials’.
• Parallel Lines: These represent the process steps. The arrows that connect these steps show the flow of energy/costs/materials from one step to another.
• Losses: Areas outside of the flow arrows often indicate losses, inefficiencies, or waste in the system.

Creating a Sankey chart

Designing a Sankey chart involves several steps, starting with data gathering and analysis:

1. Define the System: Identify the system or process for which you are creating the Sankey diagram.

2. Select Variables: Choose the variables that you want to represent, such as energy, water, or material throughput.

3. Data Collection: Gather the necessary flow data from the system’s processes — this could include input, transformation steps, and output.

4. Flow Analysis: Calculate the flow rates and losses throughout the system to help with the visualization of energy or material flows.

5. Select Software or Tools: Use specialized software or custom scripts. Many programs, including Python with libraries like Sankey diagrams or professional tools like Sankey Editor, can help you create accurate diagrams.

6. Construct the Diagram: Input your flow data into the selected tool to build the diagram. Adjust the widths of the arrows according to the quantity of materials or energy.

7. Review and Adjust: Once the diagram is created, review it for clarity and accuracy. Ensure it is easy to interpret and that the relationships between different processes are clear.

Applications of Sankey diagrams in sustainability

Sankey charts have been used in numerous sectors to identify inefficiencies and improvements in sustainability:

1. Energy Systems: Visualizing power generation and distribution, examining how energy is produced and used, and identifying areas for improvement in energy efficiency.

2. Manufacturing Processes: Understanding material flows, from raw material extraction to product life cycles, helping to discover waste and inefficiencies.

3. Financial Flows: Tracking and optimizing the movement of money within a company or across industries to identify potential areas for economic sustainability.

4. Water Resources: Revealing water cycling within a system, such as a region or urban area, to inform water management and usage decisions.

5. Environmental Impact Assessments: Helping to identify the environmental footprint of a project or process by quantifying the flow of emissions, pollution, and other environmental impacts.

Conclusion

Sankey diagrams offer a unique approach to visualizing complex processes. By stripping away the noise and focusing on the quantity and direction of flow, they help us better understand sustainability challenges and opportunities. With the right approach and tools, the art of Sankey diagrams can be a powerful ally in the quest for a more sustainable future. Whether you’re an energy systems analyst, a manufacturing engineer, or a financial planner, the nuanced narrative of Sankey charts promises to streamline sustainability, one diagram at a time.

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.