The Ministry of New and Renewable Energy (MNRE) has issued the draft Firmware Development Guidelines for local device configuration and remote communication application programming interface (API) applicable to dataloggers deployed in rooftop solar systems under the PM Surya Ghar: Muft Bijli Yojana.

Stakeholders can submit their feedback within 15 days.

The draft makes it mandatory that all firmware developers and manufacturers strictly adhere to the prescribed API specifications.

Background

MNRE introduced the draft guidelines in response to the increasing complexity in rooftop solar deployments, in which dataloggers serve as an interface between solar assets and monitoring systems.

These devices enable local device configuration, remote communication with servers, and data acquisition from inverters and meters, making their standardization essential for system reliability.

The draft lays out a detailed framework covering multiple technical complexities. These include local HTTP-based configuration, cellular connectivity settings, secure SSL-based communication with remote servers, and Modbus-based inverter communication.

It also emphasizes security features such as token-based authentication, device certificate provisioning, broker connectivity monitoring, offline historical data retrieval, and SMS-based communication mechanisms.

Commission’s Analysis

The draft highlights MNRE’s aim to standardize firmware interfaces across devices to ensure cybersecurity and data integrity within the rooftop solar ecosystem.

The framework emphasizes secure and controlled data exchange. For example, the authentication architecture relies on a token-based session management system with time-bound validity, requiring devices to validate credentials, issue tokens, and enforce expiration checks for all subsequent API interactions.

Further, the guidelines mandate certificate-based secure communication, in which credentials such as private keys must never be exposed, and TLS connections must be established with central servers.

The proposed guidelines also account for deployment challenges by incorporating mechanisms, such as SMS-based communication when internet connectivity is unavailable, to ensure continuity in data reporting.

Last December, MNRE asked all state and electricity regulatory commissions to adopt machine-to-machine (M2M) SIM-based remote monitoring systems for recording rooftop solar generation, potentially eliminating the need for separate solar generation meters.

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