The Ministry of New and Renewable Energy (MNRE) has mandated that all original equipment manufacturers (OEMs) enlisted for the supply of inverters under the PM-Surya Ghar: Muft Bijli Yojana to integrate inverter communication devices with the programme portal. This decision follows concerns that inverter communication devices were transmitting data to servers located outside India, raising the potential risk of grid disruptions. All such devices must also be linked to software managed by the MNRE or any other designated agency. The integration process will begin with a testing phase from September 1, 2025. According to the guidelines, all inverter communication devices, dongles, and data loggers must operate on machine-to-machine SIM communication protocols to ensure secure and reliable data transfer.
Additionally, MNRE has issued draft guidelines for remote monitoring systems (RMS) and inverter communication devices under the scheme. These aim to establish a secure and multi-layered protocol to ensure reliable data capture and transmission from rooftop solar installations. RMS devices must be registered using their international mobile equipment identity number and must support secure communication using AES-256 encryption via transport layer security or secure sockets layer protocols. Each device will be assigned a digital certificate for authentication, and a time-sensitive one-time password will be used in every message for transaction-level security. Upon registration with the centralised Internet of Things platform, vendors will receive essential credentials such as client certificates, authentication tokens, and server URLs via a secure API. Certificate renewals and updates will be managed through file transfer protocol.
Communication between RMS devices and servers will follow the message queuing telemetry transport protocol with a detailed topic structure for default data, periodic reports, alarms, and on-demand commands. This allows for both real-time and historical data access. The guidelines also define communication modes including scheduled pushes of inverter and sensor data, event-triggered alarms, and on-demand read and write functions that enable remote diagnostics and control. Configurations such as inverter set points, battery parameters, and data intervals can be modified remotely using pre-defined commands. The unified message format is based on JavaScript Object Notation, and parameter standards are consistent across various equipment, including inverters, meters, weather stations, and string combiner boxes, to ensure seamless data interpretation by the central server.
