Cybersecurity Alert: Hidden Threats in Chinese Solar Inverters Discovered

The short version

• The find: U.S. experts found undocumented communication devices, including cellular radios, in some Chinese-made solar inverters and batteries, Reuters reported on May 14, 2025.
• Potential Risk: Hidden radios could let someone bypass firewalls and change or shut down inverters remotely, which could affect power grids.
• Key Players: U.S. energy officials were reassessing the risk, and European governments were also reviewing Chinese inverters.
• Calls for Action: Experts urged full inventories of inverter communications and stricter rules on remote access.

Hidden radios in grid equipment

Solar inverters convert power from panels into electricity the grid can use. Most are made in China. Reuters reported that U.S. energy experts who took some apart over the previous nine months found communication components that were not listed in product documents, and the U.S. government had not publicly confirmed the findings. The Department of Energy said it was assessing risks from new technology and working to make grid equipment more trusted.

What investigators found

Radios that should not be there

Inverters usually allow remote access so manufacturers can update software and run maintenance. Utilities normally put firewalls in the way. Built-in cellular radios would offer a separate path around those defenses, and people familiar with the findings told Reuters that the devices could be used to switch inverters off or change their settings, which at scale could destabilize parts of the grid.

Reuters did not name the manufacturers involved. It noted that rogue communication devices had also been found in some batteries from several Chinese suppliers.

Who’s Affected?

Any country with a lot of Chinese inverters on its grid has a stake. That is most of Europe. Lithuania had already passed a law blocking remote Chinese access to larger solar and wind installations, and Estonia was assessing the risk. Officials in the UK were reviewing Chinese-made components in the energy system.

How governments responded

Working together

Governments on both sides of the Atlantic started looking harder at who can remotely control grid equipment. In the U.S., lawmakers had already proposed bills to restrict purchases of batteries from some Chinese suppliers.

An earlier version of this article included a quote from an unnamed cybersecurity professional. Because it could not be traced to a person or publication, it has been removed.

What operators can do

Utilities and large solar operators can audit what each inverter can talk to, including any cellular or wireless modules hidden inside. Ask suppliers for documentation. They can require every communication component to be listed and test equipment before it is installed.

Longer term, regulators are weighing certification rules for inverters and limits on vendor remote access. Monitoring for unexpected network traffic from inverters is a practical step operators can take now.

What comes next

The Reuters report turned a long-running concern about Chinese grid equipment into a concrete finding. For Europe and the U.S., the question is no longer whether inverters can be controlled remotely. It is who holds that control. And who checks it?

Every operator, from utilities to homeowners with rooftop panels, can start by knowing which devices are connected and who can reach them.

John King, CISSP, PMP, CISM

John King currently works in the greater Los Angeles area as a ISSO (Information Systems Security Officer). John has a passion for learning and developing his cyber security skills through education, hands on work, and studying for IT certifications.