The MESA-Device Draft Specification proposes standards for how the different components of an energy storage system (power meters, power conversion systems, and batteries) communicate with one another. The specification is based on previous work from the SunSpec Alliance, extended via a joint development effort between SunSpec and MESA. The specification consists of three components; see below for a description of each component and links to the relevant documentation.

MESA-Device/SunSpec Energy Storage Model builds on SunSpec’s model-based framework. To acquaint yourself with the architectural concepts, start your reading with SunSpec Technology Overview – 12040 and SunSpec Information Model Reference. SunSpec’s Inverter and Meter model specifications are available for download with a free account here.


This specification builds on the SunSpec model-based framework, but it defines new models that address the capabilities and requirements of energy storage devices. The document outlines the approach and the initial models, and the spreadsheet provides the details of each model. An archived version of the previous draft is included below.

The Energy Storage Workgroup, run by SunSpec Alliance with contributions from MESA members, worked through 2015 and 2016 to produce an updated draft specification for MESA-Device/SunSpec Energy Storage Specification (Draft 4). The specification was released in DRAFT status for feedback and testing in July 2016.



This documentation, based substantially off of the SunSpec Inverter model specifications, outlines a vendor-specific model extension to SunSpec’s work that provides a standard way for a PCS to support key energy storage scenarios. The document describes the SunSpec models adopted by MESA and the rationale for the needed extensions and overviews the Modbus registers that are prescribed in the specification. The spreadsheet then contains the details of the registers and expected values.

MESA-Power Meter

For power meters, MESA has adopted SunSpec’s Meter Models v1.2 or later available at the link listed below. Therefore any power meter that is SunSpec compliant and implements a Modbus/TCP interface is deemed to be MESA-Device compatible.

Thank you for your interest in MESA-Device. To join the effort and contribute to the specification’s evolution as well as other MESA efforts, click here to join MESA as a contributing member. For questions or to comment on the work, please email