Energy Academy
Variable-Speed Drives & Control6 / 13

VFD Applications & Savings

Pumps, fans, compressors: where VFDs save the most, and typical payback.

10 min read · Jacob Willis, Net Zero Lead · Last reviewed July 2026


The previous lesson's cube law makes variable-speed drives look like magic, and on the right load they nearly are. On the wrong load they are an expensive box that adds losses. The difference is entirely in how the load's power demand changes with speed, and loads fall into three families that decide the answer before any vendor is called. This lesson sorts real site equipment into those families.

In this lesson

  • 01The three load families
  • 02Where the site savings actually are
  • 03Sources and further reading