Articles | February 23, 2023
Visualizing Energy Flows: How Sankey Charts Illuminate Efficiency Gaps

The quest for enhanced energy efficiency has been a cornerstone of global efforts to mitigate climate change and ensure sustainable development. Sankey diagrams, named after Sankey’s pioneering work in 1898 on energy flows across steam engines, have evolved into a powerful tool for visualizing and analyzing how energy is transformed, lost, or consumed across various systems. From industrial processes to energy supply chains, Sankey charts offer a clear, comprehensive view, making it easier to identify and address inefficiencies and sustainability issues.

Understanding Sankey Charts

Sankey diagrams consist of arrows or bands of different widths that represent resource flows (e.g., energy, material flows) and their transformation between various processes. The width of the arrow typically represents the quantity or amount of material transmitted. These diagrams are particularly useful in understanding the energy efficiency of a system by illustrating where energy is transformed into waste, used inefficiently, or lost.

Creating a Sankey Chart

Creating a Sankey chart involves several steps and requires data on the inputs and outputs of your system. Here’s a simplified guide to get you started:

1. Data Collection: Gather accurate data on all the inputs and outputs (i.e., energy consumed or produced) at every stage of your system. This data should ideally be measured in absolute terms to understand the magnitude of energy flows.

2. Normalization: Once you have your data, normalize it to ensure a fair comparison. If you’re comparing different processes or systems, ensure they are normalized to the same total (e.g., energy input or output). This step is crucial for clear interpretations.

3. Choosing an Interface or Tool: There are various tools and software programs available for creating Sankey diagrams, including statistical software (e.g., R and Python) and dedicated diagramming software (e.g., SuperCharts, Tableau, and Microsoft Excel). Online Sankey diagram makers, such as infogram or biofuelscan.org, can also be very helpful for creating interactive and visually appealing Sankey charts.

4. Design and Layout: Once you’ve selected your interface, design your chart. Arrows can represent different types of energy (or products in non-energy systems) flowing from the source (e.g., grid) through different processes to the final destination (e.g., a machine receiving power). Ensure the scale and the placement of your legend are clear for easy interpretation.

5. Validation: Finally, validate your Sankey chart. Ensure all inputs and outputs are accurately represented, and that the visualization accurately reflects the data. It’s also beneficial to share your diagram with colleagues and experts for feedback.

Applications and Benefits

Sankey diagrams are invaluable across a broad range of industries and applications, including:

• Energy Auditing: These diagrams help in identifying the sources of inefficiency within a building or industrial facility. In energy audits, Sankey diagrams can highlight the energy losses in a building or the inefficient use of energy in a process.
• Energy Supply Chain Visibility: By visualizing the energy transitions and losses across a supply chain, Sankey diagrams can help identify areas where improvements could be made.
• Environmental Impact Assessment: These charts can also be used for assessing the environmental impact of different products or processes by visualizing the energy and material flows.

Conclusion

Sankey diagrams provide a powerful method for visualizing and analyzing complex energy and material flows. By identifying and highlighting inefficiencies and losses, they offer a clear pathway to improving energy efficiency and supporting sustainable development. Whether for auditing, supply chain analysis, or environmental impact assessment, the insights gained from Sankey diagrams can be pivotal in guiding the way forward. As awareness of sustainability issues grows, the role of visualization tools like Sankey diagrams in driving change and innovation in the sector is likely to expand.

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.