Solid-State Transformers: Measured Progress and Voltage Limits in Addressing AI Data Center Power Bottlenecks
The expansion of AI data centers is encountering a subtle but increasingly urgent hardware bottleneck: transformers. Benjamin Boucher, a supply chain analyst at the energy research firm Wood Mackenzie, notes that the wait time for delivering large traditional transformers—needed to connect new power plants, transmit electricity over long distances, and serve high-demand sites like data centers—has stretched to five years.
The basic design of traditional transformers has remained largely unchanged for nearly a century: the core consists of grain-oriented electrical steel, with copper coils wound on either end, stepping voltage up or down through magnetic induction. Manufacturing these devices requires significant specialized labor and complex processes; even new production facilities announced years ago have struggled to come online. "Transformers have become one of the biggest bottlenecks for utilities, generation developers, and even data centers," Boucher said.
The concept behind solid-state transformers involves adding power semiconductors to the traditional magnetic induction framework. Srdjan Lukic, a professor of electrical and computer engineering at North Carolina State University, explained that solid-state transformers first convert incoming alternating current (AC) into direct current (DC), then use semiconductor switches made of materials like silicon carbide to convert it into high-frequency AC. A smaller magnetic core handles the voltage transformation before converting the power back to the required frequency. Because semiconductors allow precise control over current frequency and stability, the magnetic core can be reduced to about one-tenth the size of a traditional transformer while maintaining the same capacity.
In August 2026, the New York Power Authority and the Electric Power Research Institute (EPRI) completed a megawatt-scale test of a solid-state transformer under realistic utility conditions at an EPRI testing site. The device was built in Lukic’s lab and represents the first such test for a transformer of this capacity, according to him. The prototype achieved approximately 98% efficiency, meaning it lost only 2% of the input energy. Lukic stated that an equivalent combination of a traditional transformer and rectifier would have roughly 96% efficiency combined. This 2-percentage-point difference is significant, as it implies that solid-state transformers could cut power losses from conventional equipment in half.
On the commercialization front, Heron Power raised $140 million in February 2026 to bring its solid-state transformer, named the Heron Link, to market. Founder and CEO Drew Baglino stated that the technology could be used in data centers, solar power arrays, and grid storage batteries. The company is constructing a $100 million factory in California, planning to begin production in 2027 and reach full capacity of 40 gigawatts of transformers per year by 2029. Heron employs a modular design to address the higher failure modes associated with power semiconductors: if a single module fails, the rest of the system continues to operate without requiring a complete shutdown.
Sources:MIT Technology Review