SunSpec Modbus

SunSpec Modbus is an open standard that specifies common parameters and settings for monitoring and controlling Distributed Energy Resource (DER) systems.  SunSpec Modbus is specified in IEEE™ 1547-2018, the U.S. national standard for DER.

Features and Benefits

  • Enables multi-vendor interoperability for manufacturers of solar inverters, energy storage devices, trackers, meters, and other DER devices. 
  • Semantically identical and fully interoperable with IEEE 2030.5 and IEEE 1815 communication protocols, thus ensuring a high signal-to-noise ratio for  DER networks.  
  • Specified in IEEE 1547, the national DER standard in the U.S., as a standard communication interface option. 

Understanding SunSpec Modbus

To understand what SunSpec Modbus is and how to use in your product interface or DER system design, follow these steps.

1. Technology Overview

Provides a theory of operation for the SunSpec Modbus interface. Click the orange header text below to download.

2. Model Reference

Describes the contents of SunSpec Modbus models. In Excel format. Click the orange header text below to download.

SunSpec Information Model Reference

Describes SunSpec Modbus data points and information models for all types of DER devices including inverters, batteries, meters, and trackers. Published in Microsoft Excel format. Download Specification...

3. Model Specification

Describes the detailed information required to understand SunSpec information modeling and create SunSpec compliant implementations. Click the orange header text below to download.

SunSpec Information Model Specification

Provides an overview of SunSpec information models associated with the physical devices comprising a photovoltaic system. This document provides communication interface developers with detailed information needed to define...

SunSpec Modbus Use Cases

SunSpec Modbus supports the concepts of use cases and profiles. For example, California Rule 21 is a use case for SunSpec Modbus. A California Rule 21 profile document specifies the SunSpec Modbus Information Models that are required to form a compliant interface for this use case.

California Rule 21

This document describes the SunSpec Modbus information models required to implement a DER communication interface (e.g. solar inverter or energy management system) that complies with California Rule 21 Phase 2 and Phase 3 requirements. Click here to download.

Energy Storage

This document describes the SunSpec Modbus information models required to implement a DER communication interface to support energy storage applications, including those specified by the MESA Alliance. The SunSpec Modbus Energy Storage information models are currently in TEST status. When approved, these models will be added as the “800 series” into the SunSpec Information Model Reference and the SunSpec Modbus Energy Storage Specification document will be updated to APPROVED status. Click here to download.

IEEE 1547-2018 DER

This set of documents describe the SunSpec Modbus DER information models required to implement and IEEE 1547-2018 compliant DER interface. The SunSpec Modbus DER information models are currently in TEST status. When approved, these models will be added as the “700 series” into the SunSpec Information Model Reference and the SunSpec Modbus Technology Overview document will be updated. Go to the New Technology page to learn more and download these documents.