Sankey diagrams, often known as Sankey charts, have emerged as a highly effective visualization tool for illustrating complex systems and processes that involve materials and energy. Whether they’re used in analyzing industrial systems, energy flow in ecosystems, or tracking financial transactions, Sankey charts provide a clear view of how resources are distributed across networks and processes.
At heart, a Sankey chart consists of parallel arrows that represent flows. These arrows are arranged horizontally or vertically, and their shape and length provide insights into the proportionality of the flows. The thickness of each path illustrates the volume of a particular flow, while changes in stream width denote the overall efficiency or intensity of the system being charted.
### Insight into the Flow Dynamics
One of the primary attractions of Sankey charts is their incredible ability to depict both the magnitude and the direction of flows. For example, in a manufacturing plant, a Sankey chart can reveal how raw materials enter, are transformed into products, and are eventually released as waste or sent as output.
#### Industrial Processes
In the context of industrial processes, such as the production of electric vehicles (EVs), a Sankey chart would illustrate the extent of resources like steel, battery materials, and fossil fuels that are consumed, the efficiency of recycling materials, and the final energy output—be it the kinetic energy of an EV or the power generated from selling scrap materials.
### Energy Flow Analysis
When it comes to energy systems, Sankey charts offer an intuitive way to visualize energy loss and conservation. For instance, they are often used to assess energy efficiency in power generation, such as comparing the efficiency of a traditional coal power plant versus a modern combined cycle gas plant.
#### Power Generation
In a power generation context, the chart could show that although a lot of power might be released from the turbines, a significant portion is ultimately lost as waste heat or in transmission lines. The Sankey chart could also track the origin of the coal, whether it’s locally sourced or imported, illustrating supply chain dependencies and environmental implications.
### Environmental Modeling
Environmental scientists and policymakers find Sankey diagrams particularly valuable in modeling and communicating the complex interactions between humans and the environment. They can depict the flow of carbon, nitrogen, and other nutrients through ecosystems, enabling stakeholders to understand the environmental impact of various processes.
#### Ecosystem Dynamics
For instance, a Sankey chart of an urban ecosystem could illustrate food webs and metabolic cycles, demonstrating how energy and material flow through plants, animals, and waste decomposition. By highlighting areas where flows are particularly high, such as during a population bloom, it becomes clearer how disruptions in one flow can have cascading effects on the whole system.
### Data-Driven Decision Making
Sankey charts aid in identifying process bottlenecks, energy losses, and inefficiencies across systems. The graphic representation makes complex information more accessible and actionable. For engineers and project managers, these insights can provide a roadmap for improvement.
### Conclusion
Sankey charts are more than just another kind of chart—they are a powerful tool that can transform complex, often intangible data into a visual narrative. From industrial production to environmental conservation, these charts illuminate the flow of materials and energy, providing new perspectives and facilitating data-driven decisions throughout the design, analysis, and optimization stages of any project or process.
