How can energy inefficiencies be represented in a model?

Energy inefficiencies can be represented in a model through the use of energy flow diagrams or Sankey diagrams.

Energy flow diagrams, also known as energy transfer diagrams, are graphical representations that illustrate how energy is used and lost within a system. These diagrams often depict energy inputs, outputs, and losses, providing a clear visualisation of energy inefficiencies. For instance, in a model of a car engine, the energy input would be the fuel, the output would be the motion of the car, and the losses would be heat, noise, and exhaust emissions. The larger the energy loss, the more inefficient the system.

Sankey diagrams are a specific type of energy flow diagram that are particularly useful for representing energy inefficiencies. They are drawn to scale, with the width of the arrows proportional to the amount of energy they represent. This allows for a clear visual comparison of energy inputs and outputs, making inefficiencies immediately apparent. For example, in a Sankey diagram of a light bulb, the input energy would be the electrical energy supplied to the bulb, while the outputs would be light and heat. If the arrow representing heat is larger than the one representing light, this indicates that the bulb is inefficient as it is wasting more energy as heat than it is using to produce light.

In both types of diagrams, energy inefficiencies are typically represented as energy losses. These losses can occur due to a variety of factors, such as heat loss through conduction, convection, and radiation, or energy loss through friction or air resistance. By identifying and quantifying these losses, these diagrams can provide valuable insights into where and how energy inefficiencies occur, and how they might be reduced.

In conclusion, energy flow diagrams and Sankey diagrams are powerful tools for representing energy inefficiencies in a model. By providing a clear, visual representation of energy inputs, outputs, and losses, they can help to identify and quantify energy inefficiencies, and provide insights into how these inefficiencies might be reduced.