When flow rate through a pump system is controlled by a discharge throttle valve, there is valuable energy going to waste. (It’s like driving with your brakes on.)

A Variable Frequency Drive (VFD) can harness that energy by matching pump speed to flow rate.

To calculate the potential savings, measure the pressure drop across the throttle valve and use this formula:

The savings may pay for that VFD upgrade. Also check for utility company rebates.