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Utah State University Extension

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Many irrigation systems have variable flow and pressure needs. Variable frequency drives (VFDs) are electric controllers that vary the speed of the pump motor, allowing the pump to respond smoothly and efficiently to fluctuations in flow and/or pressure demand (Stover, 2019). They are also sometimes referred to as variable speed drives (VSD). When installed correctly in the right applications, they can effectively reduce energy costs, decrease electrical system stress, and extend the life of a pump.Due to their effectiveness, many energy companies and governments cost-share or incentivize their use.This can sometimes lead to VFDs installed on pumps where costs outweigh benefits.This guide will help irrigators and irrigation dealers understand when and where VFDs make sense.

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