Most people rarely consider the role transformers play in powering our homes until we hear the loud “bang” followed by widespread outages. But as large loads such as artificial intelligence, data centers, and manufacturing consume even more electricity, transformers are becoming stressed from the increased demand. 

Electrical engineering expert Ali Mehrizi-Sani explains why transformer reliability matters and what engineering innovations can strengthen the nation's energy infrastructure.

Why are transformers a growing concern for the nation's electrical infrastructure, and why should the public care?

“Transformers are essential for delivering electricity. Almost all electric power we consume passes through transformers multiple times: first to increase or “step up” the voltage for more efficient long-distance transmission and then to decrease or “step down” the voltage for safe delivery as it gets closer to homes and businesses,” Mehrizi-Sani said.

“Unfortunately, transformers are also among the hardest grid components to replace. Many are aging, and large transformers are custom-built and difficult to transport. While transformers are generally very reliable, a single failure can cut power to thousands of customers.”

How is the rapid expansion of AI and data centers putting additional pressure on transformers and the electrical grid?

“As our dependence on electricity grows, so does our need to generate more power and transmission must keep pace—a shift that requires more transformers across the network,” Mehrizi-Sani explained.

“Additionally, existing transformers are likely operating closer to their maximum capacity. While this can improve efficiency, it also leaves less flexibility for the power grid to deal with disturbances and fluctuations in electricity demand.” 

Why is transformer reliability a national security concern?

“The power grid is a critical infrastructure that underpins virtually every other critical infrastructure, including defense, communications, transportation, and water systems,” Mehrizi-Sani said. “Transformers are critical points in this interconnected system.”

”Aging units increase concerns of failures due to natural disasters, equipment deterioration, or even physical and cyberattacks,” he explained.

“Replacing them is also a challenge due to supply chain and manufacturing issues. In 2019, 82 percent of large power transformers purchased for use in the U.S. were imported, and replacement lead times can be as long as three to five years. A widespread failure could therefore have consequences extending far beyond the power grid.”

What engineering innovations or emerging technologies could reduce these vulnerabilities?

“We need more flexible infrastructure that can keep operating even when one or more transformers fail. This can be achieved in several ways, but all require further investment in research and development, industry support, and related policies and regulations,” Mehrizi-Sani stressed.

“Potential solutions include standardizing transformer designs, optimizing the location and number of storage facilities for spare transformers, developing more flexible transformer technologies (such as solid-state transformers), and enabling portions of the grid to operate independently as microgrids during disruptions to ensure continuity of service.”

“For the everyday consumer, participating in demand response programs during periods of high power demand can also help with stress on transformers and the grid.”