China implicated after U.S. finds hidden radios in imported solar tech 

The U.S. Federal Highway Administration circulated the advisory on August 20, cautioning that it discovered undocumented cellular radios in some foreign-manufactured inverters and battery management systems.

These components are used in roadside equipment such as traffic cameras, weather stations, electric vehicle chargers and even solar-powered rest stops.

The discovery has brought back the debate on the reliance on foreign technology, especially Chinese-manufactured equipment, in the U.S.

Undocumented devices raise security alarms

U.S. transportation officials are warning that hidden radios and other undocumented devices may be embedded in solar-powered highway infrastructure, raising fears of foreign surveillance and sabotage in critical American systems.

“That could create a lot of havoc,” said Anomadarshi Barua, a George Mason University academic who has studied vulnerabilities in inverters. He warned that rogue radios could be weaponized to disrupt roadside systems. Barua also said that with the increasing adoption of autonomous vehicles, these rogue radios could compromise the systems that help keep them safe on the road.

The Federal Highway Administration note did not specify which countries the compromised equipment came from, but many inverters used in American infrastructure are made in China. The Chinese Embassy in Washington rejected the allegations, saying it opposed “the distortion and smear of China’s achievements in the field of energy infrastructure.”

A precursor to a blanker import ban on China

In May, Reuters reported that “rogue communication devices” had been detected in Chinese-made inverters and batteries, setting off alarms about potential vulnerabilities in the U.S. power grid. Denmark’s national renewable energy group also raised similar concerns last month, saying that unexplained components had turned up in imported equipment destined for its energy network.

U.S. agencies have already moved to limit Chinese presence in other areas of transportation. In January, the Commerce Department finalized rules that will bar nearly all Chinese cars and trucks from American roads by 2026, citing concerns that vehicle software and hardware could collect sensitive data or allow remote manipulation.

The Federal Highway Administration’s advisory urged operators to inventory inverters across the U.S. highway network, use spectrum analysis tools to detect any unexpected communications, disable or remove undocumented radios, and properly segment networks to reduce risk.

The Department of Transportation said the notice summarized unclassified reporting and was intended to ensure agencies take “practical mitigation steps.”

Some security experts argue that the advisory is as much about signaling as it is about technical threats. In recent times, both Democrats and Republicans have increased rhetoric about the threat of Chinese technology, portraying it as a potential Trojan horse.

With hundreds of billions of dollars earmarked for green infrastructure, the push to source equipment domestically is likely going to see a rise which has seen a boost in recent times thanks to President Donald Trump’s America first push.