Circa 2017

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Transformers are found at generating stations and distribution substations. Their primary function is to reduce the high voltages used to transport electricity long distances to the lower voltages needed by homes and businesses. But today’s transformers only operate in one direction. They are poorly equipped for boosting electricity from local sources — typically wind and solar — to the higher voltages needed to mesh efficiently with the larger grid.

Beginning in 2,010 researchers at the National Science Foundation’s FREEDM Systems Center at NC State introduced the first solid state transformer. It could perform all of the functions of a traditional transformer, but could also redirect power as needed to address changes in supply and demand.

“The SST is a fundamental building block in the smart-grid concept,” says Iqbal Husain, a professor of electrical and computer engineering at the school and director of the FREEDM Center. “It can scale down voltage for use in homes and businesses, but it can also scale up voltage from solar panels or other residential-scale renewable sources in order to feed that power back into the grid. And because the SST is a smart technology, it can switch back and forth between those two functions as needed.”