Are Chinese Solar Inverters a Security Risk in the UK?

Are Chinese solar inverters a security risk? For a UK homeowner the honest answer is: there is no public evidence that a home inverter has been used to attack the UK grid, but regulators on both sides of the Atlantic have taken the question seriously enough to change funding rules, and the UK is now writing cyber security requirements for home batteries. Since Huawei, Sungrow and Solis are all common names on UK quotes, this guide sets out what has actually been reported, what has not, and what you can do about it.

Why inverter security is in the news

The inverter is the internet-connected brain of a solar system. It converts the panels' DC output to AC, and most modern units also talk to a cloud monitoring service so you can see generation in an app. That connection is what makes them a security topic: a device that can report data can, in principle, also receive instructions.

Two developments drive the current debate. First, in May 2025 Reuters reported, citing anonymous US government sources, that undocumented communication devices, including cellular radios, had been found in some Chinese-made inverters and batteries. The sources said the components were not listed in the products' documentation and could in theory let firewalls be bypassed remotely. There was no confirmation that they had been used maliciously, and a Chinese government spokesperson rejected the reporting as an attempt to smear China's infrastructure achievements.

Second, the European Commission announced in May 2026 that it will progressively phase Chinese-made inverters out of EU-funded energy projects, naming Huawei and Sungrow among the affected suppliers. The restrictions are due to be fully written into new contracts from April 2027. The Commission put the extra cost of switching at under 2% of total project cost, because inverters are only around 5% of large solar project costs.

What the evidence does and does not show

What is documented:

• Market concentration. DNV data cited by Defense News put Chinese vendors, chiefly Huawei and Sungrow, at 78% of inverters installed across Europe in 2023.
• Undocumented hardware reports. The Reuters story above, sourced to unnamed officials and not independently published as a technical report.
• Ordinary vulnerabilities are not limited to China. In the US, the cybersecurity agency CISA published an advisory on inverters from Texas-based EG4 Electronics, affecting roughly 55,000 customers, after finding unencrypted communications and firmware updates with no integrity checks.

What is not established: that any Huawei, Sungrow or Solis home inverter in the UK has been remotely controlled by a foreign state. Defense News notes that inverters in the US, UK and Pakistan were switched off remotely in November 2024, but that investigators linked it to a commercial dispute rather than a security attack.

Residential equipment also sits in a regulatory grey area: in the US, cyber standards for home systems are voluntary rather than mandatory, unlike utility-scale plants, according to TechCrunch's reporting.

Scale matters: one home inverter versus a fleet

The grid-level worry is aggregation. One 5kW inverter switching off is invisible to the National Grid. Hundreds of thousands switching at once is a different matter, which is why policy attention focuses on remote access to large fleets and on the largest vendors. Your own system is a very small part of that picture, but the same design choices (remote access, cloud accounts, firmware updates) apply to it.

What is the UK doing about it?

The government's Smart Secure Electricity Systems (SSES) programme is the main UK route. Its first-phase consultation, which closed on 5 February 2026, proposes regulations that would require smart home batteries (defined as 1kWh or more of storage and at least 1kW output, sold with smart capability), EV smart charge points and certain electric heating appliances to comply with the ETSI EN 303 645 IoT cyber security standard. The proposed requirements would come into force from 31 December 2027.

The consultation document names batteries, EV chargers and electric heating. It does not list solar inverters as a separate category, so a standalone string inverter is not clearly covered, although an inverter sold as part of a smart battery system may be. Rules also remain proposals until regulations are laid before Parliament. Treat 2027 as the direction of travel, not a guarantee.

Practical steps for UK homeowners

1. Ask the installer where the monitoring data goes. Which cloud provider, in which country, and whether the system works if you disable remote access.
2. Keep firmware up to date and use a unique, strong password on the monitoring account, with two-factor authentication where the app offers it.
3. Put the inverter's Wi-Fi on a separate guest or IoT network rather than the one your laptops use.
4. Do not expose the inverter to the internet with port forwarding. Local integrations such as Modbus or Home Assistant should stay on your home network; see home energy monitoring.
5. Weigh brand origin as one factor, not the only one. Warranty support, MCS-certified installation and safety record matter as much. Our Sigenergy vs Sungrow vs Solis comparison and hybrid inverter buyer guide cover the practical differences, and best solar inverters UK lists alternatives including non-Chinese brands.

Should you avoid a Chinese inverter?

There is no UK ban, no UK advice to remove existing inverters, and installing one remains legal and MCS-eligible. If your priority is minimising geopolitical risk, you can ask for a European, Japanese, Korean or US-made alternative; the EU's own list of approved alternative suppliers covers Japan, South Korea, Switzerland and the United States. Expect to compare quotes, since price and battery compatibility vary. For most households, good network hygiene and a reputable installer reduce more real-world risk than the country of manufacture alone. Our guide to smart inverters explains what remote functions your unit may have.