Losses are inevitable in "transport" activities, whether the transport refers to the transport of energy such as electricity, or fluids such as liquids or gases such as compressed air systems or pneumatic movement of materials.

For electricity, the losses are proportional to the "square" of the current (the well known I2R formula), while for fluid transport in pipes or conduits, the losses are proportional to the "cube" of the flow rate. The energy cost of a process over the lifetime of the facility is often much greater than the capital cost of the energy using equipment. Hence it pays to design the system to optimise the "total cost of ownership", rather than just the capital cost alone.

In practice, the proportional energy losses can be reduced significantly by over-sizing the installation, e.g., the conductors or the pipes. The extra cost of such over-sizing is normally low, as the extra cost of the larger materials may be only marginal.

The charts below show the proportional energy losses for varying ratios of "sizing", where 1.0 per unit cost against 1.0 per unit losses represents the case for the nominal design dimensions.

Electrical Losses

Fluid Flow Losses

In practice the effect of surface resistance in pipes as well as the fluid viscosity will moderate the relationship slightly, but the nominal proportionality remains.

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