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Press Release: Secure SunSpec Modbus Certification
SunSpec Alliance / Press Release
SunSpec Alliance Announces Approval of Secure SunSpec Modbus Test Procedures
New certification program advances secure, interoperable communications for distributed energy resources
CAMPBELL, Calif. — SunSpec Alliance announced the official approval of the Secure SunSpec Modbus Test Procedures, marking a significant milestone in the advancement of secure communications for distributed energy resources (DERs). Following a successful member vote, the Test Procedures were formally promoted to APPROVED status on October 7, 2026, completing a collaborative development process that included extensive public review, technical evaluation, and comment resolution.
With both the Secure SunSpec Modbus specification and its accompanying Test Procedures now approved, manufacturers can pursue Secure SunSpec Modbus Certification, establishing a standardized pathway to demonstrate conformance with enhanced cybersecurity capabilities for SunSpec Modbus-enabled devices.
Advancing Security Through an Established Industry Standard
SunSpec Modbus has long provided a standardized interface for communication with solar inverters, energy storage systems, and other distributed energy resources. As these technologies become increasingly interconnected and integral to grid operations, the requirement for secure, interoperable communications continues to grow.
Secure SunSpec Modbus addresses these evolving requirements by introducing security capabilities to the established SunSpec Modbus interface, including:
Mutual Authentication
Based on the Modbus TCP/Security standard, Secure SunSpec Modbus supports authenticated, encrypted communications between devices and connected systems, helping protect against unauthorized access and interception.
Role-Based Access Control
In alignment with IEC 62351-8 to support global cybersecurity regulations such as the European Union’s Cyber Resilience Act (CRA), Secure SunSpec Modbus establishes mechanisms for managing access permissions according to defined roles, supporting more secure interactions with DER equipment.
Standardized Conformance Testing
Provides approved test procedures through which manufacturers can demonstrate implementation of the specification's security requirements.
Adaptable and Future-Proof Design
Built on open standards and extensible cryptographic architecture, Secure SunSpec Modbus allows legacy and next-generation DER deployments to seamlessly incorporate updated security parameters, algorithms, and regulatory requirements over time without requiring costly architectural overhauls.
Together, these capabilities help manufacturers strengthen device security while maintaining the benefits of a familiar, standardized communications interface.
A New Certification Pathway for Manufacturers
The approval of the Secure SunSpec Modbus Test Procedures establishes the technical foundation for the certification program, enabling manufacturers to begin pursuing certification for compliant products.
To support implementation, SunSpec Alliance has developed tools that allow manufacturers to evaluate their Secure SunSpec Modbus interfaces during development. These include self-testing capabilities through the SunSpec dashboard, helping developers identify implementation issues and prepare for formal conformance testing.
The program also includes public key infrastructure (PKI) capabilities to support the certificate-based authentication requirements of Secure SunSpec Modbus.
As manufacturer participation increases, SunSpec Alliance will work with its ecosystem of test labs to support demand and broader market deployment.
Supporting the Next Generation of Distributed Energy Resources
The launch of Secure SunSpec Modbus Certification reflects SunSpec Alliance's continued commitment to advancing interoperability, cybersecurity, and standardized communications across the distributed energy industry on an open, royalty-free basis.
By extending the established SunSpec Modbus framework with modern security capabilities, the program provides manufacturers with a practical approach to addressing evolving cybersecurity expectations without abandoning a widely adopted industry interface.
"With over 80 percent of smart inverters globally built on SunSpec Modbus, Secure SunSpec Modbus allows us to protect our industry's existing technology investments while safeguarding these vital operational endpoints against emerging cybersecurity threats," said Dylan Tansy, Executive Director of the SunSpec Alliance. "As distributed energy resources become core components of grid infrastructure, securing the point of grid interconnection is critical."
Manufacturers interested in pursuing Secure SunSpec Modbus Certification are encouraged to contact SunSpec Alliance to learn more about program requirements, implementation resources, and certification opportunities.
For additional technical background and compliance perspectives, read the SunSpec Alliance white paper, Secure SunSpec Modbus: A Familiar Interface Ready for a New Reality.
We thank our members and work group participants for their contributions throughout the development and approval process. If you are interested in participating in the Secure SunSpec Modbus Work Group, please contact membership@sunspec.org.
