Net-Metering Rules for Rooftop Solar in Tamil Nadu 2025: What You Must Know

The year 2025 marks a trans-formative period for Tamil Nadu’s renewable energy sector, with the government and Tamil Nadu Electricity Regulatory Commission (TNERC) introducing new and progressive net-metering rules for rooftop solar consumers. Under the latest guidelines, domestic consumers can enjoy enhanced flexibility in energy usage, billing, and credit adjustment, promoting broader adoption of solar energy across the state.

This article explores the Tamil Nadu 2025 net-metering framework in depth—covering eligibility, mechanisms, tariffs, application processes, and new initiatives like group net-metering—offering a complete guide for homeowners, businesses, and developers planning to adopt rooftop solar systems.

Table of Contents

Introduction

Tamil Nadu has long been a leader in renewable energy generation in India, with solar accounting for a significant share of the state’s total installed capacity. The state’s Net Metering Policy, managed by the Tamil Nadu Generation and Distribution Corporation (TANGEDCO) under the supervision of TNERC, ensures that households and institutions producing solar power can efficiently integrate it into the local grid.

The fundamental goal of the 2025 rules is to simplify net-metering, promote clean energy self-sufficiency, and make rooftop solar adoption financially attractive for consumers. The updated policy includes significant developments such as Group Net Metering (GNM) and refined tariff and feed-in structures, making solar more accessible than ever before.

Understanding Net Metering

Net metering is an arrangement where solar energy generators—typically rooftop solar panel users—can export surplus electricity back to the grid. The energy exported offsets the energy imported from the grid, allowing consumers to pay only for their net energy consumption.

In simpler terms, when your solar system produces more power than you consume, the excess power is sent to the grid and recorded by a bi-directional net meter provided by TANGEDCO. When your solar production is lower than your usage, you draw from the grid as usual. At the end of the billing cycle, your net electricity bill reflects the difference—imported minus exported energy.

The 2025 Net Metering Framework in Tamil Nadu

According to the 2025 TNERC Generic Tariff Order for Grid Interactive Solar PV Systems (GISS), the updated metering mechanisms categorize consumers into specific groups based on their connection type and capacity.

1. Domestic LT Category

Eligibility: Up to sanctioned load
Mechanism: Net Metering or Net Feed-in
Charges: 20% of Rs.1.53 for systems up to 10 kW and 75% of Rs.1.48 for capacities above 10 kW
Tariff: Feed-in tariff rates are determined by the system’s total generation and category

Domestic consumers can choose between net metering (energy-based settlement) and net feed-in (monetary value-based settlement), offering much-needed flexibility.

2. Other LT Consumers

Eligibility: Up to sanctioned load
Mechanism: Only Net Feed-in
Tariff: Rs.1.53/kWh on total generation with a feed-in tariff of Rs.3.61
Commercial and small industrial consumers under Low Tension (LT) are not eligible for net metering but can use the net feed-in system where they are compensated monetarily for energy exported to the grid.

3. High Tension (HT) Consumers

Eligibility: Solar capacities below 1 MW use net feed-in; above 1 MW operate under parallel mode with reverse power relays
Tariff: Rs.3.10 feed-in tariff per kWh applied to generators other than consumers
This segregation ensures fairness and avoids overloading the grid, while allowing commercial and high-load users to participate responsibly.

Billing and Settlement Mechanism

Under the net-metering system:

The energy exported to the grid is deducted from the energy imported from it, determining net consumption.
If exported energy exceeds imported energy, surplus units can be carried forward to the next billing cycle.
At the end of the financial year, any unadjusted excess units typically lapse unless differently specified under special categories like Group Net Metering.

In Net Feed-in arrangements, instead of direct energy adjustment, monetary values are credited and debited based on the retail tariff for import and feed-in tariff for export, respectively. The final bill reflects the difference between the two monetary sums.

Introduction of Group Net Metering (GNM)

One of the biggest advancements in 2025 is the rollout of Group Net Metering (GNM), enabling consumers to link multiple service connections under one solar rooftop system.

How GNM Works:

A domestic consumer who owns more than one property can now offset power consumption across all their service connections anywhere in Tamil Nadu.
For example, a person with a rooftop solar setup in Coimbatore can use the generated credits to offset electricity bills for another property in Chennai.
The consumer can decide the percentage of generated power allocated to each connection.

Benefits of GNM:

Promotes wider adoption of solar power across multi-property owners.
Enables better utilization of solar generation capacity.
Reduces electricity bills across multiple household or apartment units.

The Tamil Nadu Electricity Regulatory Commission (TNERC) stated that this measure promotes solar adoption among residential users who might not fully consume their generated electricity on a single property. All participating service connections are mapped on the TANGEDCO portal, and energy credits are automatically distributed according to pre-set allocation ratios.

Consumers can revise these allocation ratios twice a year with one-month advance notice, providing flexibility and control over energy management.

Net Metering vs Net Feed-in: Key Differences

Feature	Net Metering	Net Feed-in
Settlement Type	Energy balance (units-based)	Monetary balance (rupees)
Eligibility	Domestic LT consumers	All non-domestic LT and HT consumers
Tariff	Based on retail tariff	Based on feed-in tariff (Rs.3.61 or Rs.3.10 per kWh)
Carry Forward	Surplus units carried over	Monetary credits adjusted monthly
Objective	Maximize self-consumption	Promote revenue generation from solar

This dual-structure allows both residential users and commercial establishments to benefit according to their energy needs and consumption patterns.

The Application Process for Net Metering

Getting started with a new rooftop solar installation and a net-metering connection in Tamil Nadu involves straightforward steps:

Contact TANGEDCO: Obtain a net meter application form from your nearest TANGEDCO office or through the online Unified Rooftop Solar Portal (USRP).
Submit System Details: Provide information including solar system capacity, type of connection, consumer number, and premise details.
Approval and Inspection: After application submission, TANGEDCO conducts site verification.
Installation: Once approved, your existing meter is replaced by a bi-directional net meter capable of recording both import and export.
Commissioning: The rooftop solar system is synchronized with the grid, and net-metering begins.

Applications can also include subsidy eligibility verification under state and central schemes such as the Pradhan Mantri Suryaghar Muft Bijli Yojana.

Subsidies and Incentives for Rooftop Solar in Tamil Nadu

As part of the Chief Minister’s Solar Rooftop Capital Incentive Scheme, Tamil Nadu offers a state capital subsidy of ₹20,000 per kilowatt for grid-connected domestic solar PV systems. This is in addition to the central government’s 30% subsidy under the national rooftop program.

For example:

A 3 kW system can receive a total benefit of nearly ₹50,000 in capital subsidy.
Domestic consumers under 10 kW capacity also enjoy discounted network charges when opting for net metering.

These incentives have significantly accelerated the adoption of rooftop solar systems in both rural and urban households in 2025.

Emerging Trends: Net Feed-in and Government Solar Projects

The Tamil Nadu Green Energy Corporation Limited (TNGECL) has initiated large-scale adoption of rooftop solar for government buildings. In October 2025, TNGECL floated tenders for a 40 MW project under the Renewable Energy Service Company (RESCO) model, which uses a net feed-in mechanism.

This means the electricity generated by these public buildings is supplied to the grid, offsetting their consumption and reducing government energy bills. These initiatives demonstrate that the state is not just promoting solar among private consumers but actively transforming its own infrastructure.

Benefits of Net Metering for Consumers

Lower Electricity Bills: Consumers pay only for net energy usage, drastically cutting monthly expenses.
Energy Independence: Enables households to produce and consume their own renewable energy.
Environmental Impact: Reduces carbon footprint and promotes sustainable power generation.
Long-Term ROI: Typical rooftop solar systems recover their installation costs in 4–6 years through electricity savings and government incentives.
Property Value Increase: Solar-powered homes often see enhanced market values.

Challenges and Limitations

Despite the success of these reforms, a few challenges remain:

Meter Availability Delays: Processing times for meter approval and inspection can sometimes be lengthy.
Limited Commercial Net Metering: Only domestic LT consumers can opt for true net metering, limiting industrial participation.
Unit Lapsing Rules: Surplus credits lapse annually, prompting careful system sizing and consumption planning.
Technical Integration: Proper standardization of battery storage systems under TNERC’s updated hybrid model is still in progress.

However, the introduction of Group Net Metering and expanding solar subsidies are expected to address many of these issues in the coming months.

FAQs on Tamil Nadu’s 2025 Net Metering Policy

1. Who can apply for net metering in Tamil Nadu?
Domestic consumers with grid-connected rooftop solar installations up to their sanctioned load limit are eligible.

2. What happens to excess energy generated?
Any surplus energy is exported to the grid. The value or units are carried forward to the next billing cycle as per the net-metering or net feed-in mechanism.

3. Can businesses use net metering?
Commercial entities can use net feed-in, not direct net metering. They earn monetary credits for energy exported.

4. Is Group Net Metering available for all?
As of 2025, GNM is limited to domestic consumers only.

5. How often can the sharing ratio be changed under GNM?
Consumers can change their energy sharing ratios twice per financial year with one-month advance notice.

6. Are there annual settlements?
Yes, unused energy credits lapse at the end of every financial year unless specific carry-forward measures apply.

7. What is the maximum solar capacity allowed?
Residential users can install systems up to their sanctioned load, typically up to 10 kW for LT domestic connections.

Conclusion

Tamil Nadu’s Net Metering Rules for 2025 represent a pivotal advancement toward decentralized, clean energy generation. With structured incentives, the introduction of Group Net Metering, and streamlined policies under TANGEDCO and TNERC, the state aims to empower every household to become a mini power producer.

While certain operational challenges may persist, these rules solidify Tamil Nadu’s reputation as one of India’s greenest states, setting a precedent for solar energy adoption nationwide. Whether you are a homeowner seeking energy savings or a solar entrepreneur eyeing business opportunities, the 2025 net-metering regime offers both financial and environmental rewards.