India’s rooftop solar sector has reached a significant milestone—23.2 gigawatts (GW) of installed capacity as of November 2025, constituting 17 per cent of the country’s total 133 GW solar capacity. Yet this achievement conceals a critical blind spot: the government has no comprehensive data on how much electricity these systems actually generate.
While installation figures are meticulously tracked through the Union Ministry of New and Renewable Energy (MNRE)’s dashboard, actual generation data remains invisible to grid operators and policymakers. The information exists only in fragmented form—within individual consumer installations or distribution company (discom) systems that receive the supplied electricity but fail to collate it systematically. This data vacuum undermines grid management, policy effectiveness, and renewable energy accounting across a sector that spans millions of installations.
In response, MNRE formalised a transformative policy in December 2025, mandating Machine-to-Machine (M2M) SIM-based remote monitoring systems for all rooftop solar installations under the PM Surya Ghar: Muft Bijli Yojana scheme. The directive requires inverter communication devices—including dongles and data loggers—to use M2M SIM technology for real-time data transmission to centralised national servers managed by MNRE or designated government agencies.
An M2M SIM card is a specialised SIM card enabling automated communication between devices, not humans, for Internet of Things (IoT) applications
The mandate follows Odisha’s regulatory framework amendment in November 2025, when the state electricity commission (OERC) recognised M2M-enabled inverters as legitimate solar generation meters, eliminating the need for separate physical metering devices. On December 19, MNRE instructed all State Electricity Regulatory Commissions and Joint Electricity Regulatory Commissions nationwide to adopt this Odisha model as the national standard.
The technology addresses the data visibility crisis through continuous real-time transmission. Unlike traditional meters requiring manual reading or polling at intervals, M2M SIM communication provides near-instantaneous generation data, enabling grid operators to monitor aggregate rooftop solar patterns across entire distribution networks. For consumers, it also eliminates hardware redundancy—inverters now serve dual functions as both generation managers and measurement devices, reducing installation costs.
Crucially, the M2M system will enable long-term performance monitoring—addressing widespread consumer dissatisfaction with rooftop solar efficiency. Many system owners have complained about suboptimal daily generation without reliable data to verify whether their installations are underperforming due to equipment degradation, poor maintenance, or installation defects. The continuous data logging will track system performance over years, allowing consumers to identify efficiency declines and hold installers or manufacturers accountable. This transparency could improve consumer confidence in rooftop solar investments and ensure systems maintain optimal output throughout their operational lifespan.
Beyond transparency, the mandate tackles grid stability and cyber-security risks. The PM Surya Ghar scheme targets 30 GW across 10 million households, multiplying distributed generation nodes to an unprecedented scale. Managing this expansion without robust data and control systems would create an ungovernable asset base. Currently, many rooftop systems transmit data to overseas original equipment manufacturer servers, exposing inverters to potential remote manipulation. A coordinated cyberattack could disrupt gigawatts of generation and destabilise grid frequency.
The policy also resolved regulatory misalignment between central and state frameworks. In September 2024, MNRE authorised hybrid inverters—bi-directional devices managing both solar generation and energy storage. However, most state net metering regulations, issued between 2016 and 2022, permitted only grid-tied inverters and mandated separate generation meters. This created compliance conflicts for consumers attempting to participate in central government schemes.
Odisha’s amendment explicitly permitted both grid-tied and hybrid inverters while recognising M2M-enabled devices as valid measurement instruments. The December directive requires all states to incorporate similar provisions, establishing a harmonised regulatory baseline nationwide.
Implementation proceeds in phases. From September 2025, MNRE began integration testing of inverter communication devices based on vendor-neutral, open protocols. All manufacturers supplying inverters under the PM Surya Ghar scheme must ensure their devices connect to national servers, with formal implementation dates to be announced.
Despite the mandate’s forward-looking design, a significant challenge persists. The 23.2 GW of rooftop solar capacity already installed operates without generation visibility. The M2M requirement applies prospectively to new installations but does not mandate retrofitting existing systems. This creates a two-tier structure: new installations will feed data into the national system while pre-existing systems remain data-dark.
For grid operators and policymakers, this implies that 17 per cent of India’s installed solar capacity will remain in a data blind spot unless retrofits are mandated or incentivised. While the M2M mandate builds the architecture for future rooftop solar, addressing the existing 23.2 GW data gap will require additional policy interventions beyond the current framework.