Hyas Blog | Protecting Solar Inverters: Why Protective DNS Matters in the Energy Supply Chain
Solar rooftops used to just be about lower energy bills and reducing your carbon footprint. My mom even put solar panels on her roof. However, today, they’ve quickly becoming a matter of national security.
As TechCrunch recently highlighted, modern solar inverters — the brains behind those rooftop panels — aren’t just talking to your home or the grid. They’re talking to the internet. (My mom constantly reminds me of this when she complains that the solar inverter isn’t connected to her home WiFi). And that makes them part of the wider attack surface, and a clear target.
Threat actors know that if they can compromise these devices, they can do more than cause trouble for a single home or business. They can destabilize grid segments, exfiltrate sensitive usage data, or create footholds for larger-scale disruptions.
That’s where Protective DNS (PDNS) enters the picture.
The Hidden Weakness: Inverter-to-Internet Communications
Every internet-connected device relies on DNS, the “phone book” of the internet, to translate domain names into IP addresses. Solar inverters are no exception.
- They call out to cloud services for monitoring and updates.
- They exchange data with vendor networks and third-party service providers.
- And, if compromised, they can be instructed to reach out to attacker-controlled domains.
It doesn’t matter whether you’re talking about a single rooftop or a utility-scale solar farm; if the inverters can be tricked into communicating with malicious, adversary-controlled infrastructure, you have a potential national security issue. Especially if that adversary is a nation-state.
What Protective DNS Does — and Why It Helps
Protective DNS sit on the inverter itself. Instead, it guards the pathways those inverters use to talk to the outside world.
Here’s how:
- Blocks known bad destinations: If an attacker tries to direct an inverter to connect to a command-and-control domain, PDNS intercepts the query and blocks it.
- Stops data exfiltration attempts: If compromised, the inverter can’t “phone home” to malicious domains.
- Provides visibility: Security teams can see attempted lookups for suspicious domains, whether that particular domain is blocked or not, providing early warning signals of compromise.
- Protects beyond the inverter: PDNS extends protection to monitoring systems, back-office infrastructure, field laptops, and other assets and devices that connect to the same networks.
In other words, Protective DNS uses advanced infrastructure intelligence to disrupt the adversary’s playbook at one of the most fundamental layers of the internet — the DNS query itself. It doesn’t stop the bad actor (or nation-state) from breaking in; rather, it stops their attack from being able to communicate out, thus rendering it inert and ineffective, while also providing the real-time signals and alerts that something nefarious is happening.
What PDNS Can’t Do (and Why That Matters)
Protective DNS is powerful, but it isn’t a silver bullet. It can’t:
- Patch vulnerable firmware.
- Stop attacks that communicate purely over raw IP addresses (although research suggests that over 93% of all attacks utilize DNS).
- Prevent exploitation through physical access.
That’s why PDNS must be part of an overall resiliency architecture and defense-in-depth strategy that includes:
- Proper inverter and device configuration and network segmentation.
- Strong firewall rules limiting outbound communication.
- Continuous monitoring of firmware integrity and supply chain transparency.
The Bigger Picture: Securing the Energy Supply Chain
This isn’t just about a single device or a single home. It’s about national resilience.
Solar inverters are now part of the critical infrastructure conversation. Just as we protect traditional grid assets, we need to protect distributed energy resources that plug into it.
Protective DNS offers one of the fastest, most effective ways to raise the bar, cutting off known-bad communications, adding visibility into attempted attacks, and buying defenders the time they need to respond. That’s why it’s part of a zero-trust architecture, part of an overall resiliency approach, and recommended by CISA and the NSA.
Because when it comes to securing the energy supply chain, speed and visibility aren’t optional. They’re the difference between resilience and disruption.
Bottom line: Solar inverters are here to stay, and so are the threats against them. Protective DNS won’t solve every problem, but it’s one of the most important first steps in ensuring that clean energy doesn’t become a new attack surface for adversaries. HYAS with its award-winning HYAS Protect PDNS system is here to help.