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Variable frequency drives, simple motor controllers, can cut motor power use 40 to 60 percent. Few US factories use them; makers want tech firms to help pay.
2 min read
Motors wired to speed controllers in a plant room.
Illustration (AI-generated)
Variable frequency drives (VFDs) can cut a motor's power use by about 40 to 60 percent, and some 50 million electric motors run the fans, pumps and compressors in US factories and buildings. Together they use nearly a third of the country's electricity, according to Canary Media reporting republished by IEEE Spectrum. Many run flat out even when demand is low.
A variable frequency drive (VFD) is an electronic controller that speeds a motor up or slows it down to match what is needed. Without one, a motor runs at full speed and valves or dampers hold back the flow, wasting energy. Neal Elliott of the American Council for an Energy-Efficient Economy says a VFD can cut a motor's power use by about 40 to 60 percent.
A VFD lets a motor run only as fast as demand needs.
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Source · Original VoltGridNews explanatory diagram based on the cited source
Adoption is low. A 2021 Lawrence Berkeley National Laboratory report found VFDs on 16% of industrial motor systems and 4% of commercial ones. Zack Valdez of the National Electrical Manufacturers Association says builders often aim only for minimum efficiency rules. Retrofitting later also looks like a hassle.
Share of motor systems with VFDs, per a 2021 LBNL report.
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Source · Original VoltGridNews diagram; data from cited source
Toyota shows the payoff. In 2015 it spent US$1.25 million fitting drives to more than 200 motors in the air-handling system at its Georgetown, Kentucky plant. It now saves over US$700,000 a year on electricity.
Cutting motor power frees up room on the grid for big new users such as data centers. Kirk Anderson of ABB, which makes drives near Milwaukee, says putting a drive on every US motor could cover up to five years of data center growth without new power plants.
Anderson suggests tech companies pay for factory upgrades. He calls it "offset your own power" instead of building their own supply. Elliott adds that cheaper sensors, smarter software and more power chips have made drives easier and cheaper to install.
Valdez's group has started a pilot with manufacturers, utilities and efficiency groups to measure real savings. The aim is to give utilities a reason to offer rebates and to shape US Department of Energy standards. No utility program or tech company deal is described yet. Michael Reckamp of drive maker Danfoss says the technology still has not spread widely.
