The Tamil Nadu Electricity Regulatory Commission (TNERC) has released a draft of the Grid Interactive Solar Photovoltaic (PV) Energy Generating Systems Regulations, 2024, aimed at streamlining the integration of solar PV systems into the grid and ensuring regulatory clarity.

The draft regulations intend to replace the 2021 regulations, considering feedback, technological advancements, and evolving guidelines from the Ministry of Power.

The draft regulations allow domestic consumers to opt for net metering, net billing, or feed-in arrangements where imported energy is charged at retail rates, and exported solar energy is credited at feed-in tariffs determined by TNERC.

The regulator introduced a gross metering mechanism for larger systems, allowing eligible consumers and generators to sell their entire solar generation to the distribution licensee at designated tariffs. Consumers can also opt for group net metering, enabling surplus solar energy to be adjusted across multiple service connections of the same consumer within the licensee’s area of supply.

Meanwhile, the regulations allow virtual metering for distribution licensees, government bodies, and local authorities, given that the systems are at least 5 kW. Under this mechanism, solar generation can be adjusted against the consumption of subsidized consumer categories or across their service connections.

The regulations, when ratified, will apply to all electricity consumers, distribution licensees, government bodies, and generators setting up grid interactive solar PV systems in Tamil Nadu. Eligible consumers include domestic consumers, places of public worship, and service connections for common purposes in multi-tenant buildings.

TNERC has also proposed new registration fees based on the solar PV system’s capacity, categorized into low-tension (LT) and high-tension (HT) connections.

For LT connections, the registration fee for systems up to 20 kW is set at ₹500 (~$6). For systems with capacities above 20 kW and up to 150 kW, the fee is ₹500 (~$6) for the first 20 kW, with an additional ₹100 (~$1.20) for every subsequent 20 kW.

For HT connections, the registration fee is ₹5,000 (~$60) for systems with capacities above 150 kW and up to 500 kW. For those between 500 kW and less than 1 MW, the fee increases to ₹10,000 (~$120).

Domestic consumers will have the option to switch between net metering and net feed-in twice a year. Net billing or net feed-in will be available to all consumer categories except huts and agricultural services. Gross metering will be open to new and existing consumers (excluding certain low-tension categories) for systems above 150 kW up to 999 kW.

To streamline the application process, the regulations mandate a web-based application system, establish timelines for approvals, and provide guidelines for technical feasibility studies and commissioning procedures. Renewable Purchase Obligation (RPO) compliance is also addressed, with solar energy generated under virtual net metering eligible for meeting the distribution licensee’s RPO targets.

Network and wheeling charges will be applicable for most metering mechanisms, except for gross metering, with provisions for exemptions or concessions to be determined by TNERC. Additionally, network charges will be waived for exported power, but for accounting, exported units will be deducted from total generated units, and network charges will apply only to the remaining units.

Consumers and generators will also be able to connect to the grid up to their sanctioned demand by installing a reverse power relay to prevent solar power from entering the grid. They will not need a dedicated feeder and will use their existing connection. They must, however, pay network charges for all generated solar power as per Commission orders but are exempt from parallel operation charges. The solar generation meter will be installed at their own expense.

The draft regulations also cover provisions for accessing and disconnecting systems, connection agreements, and mechanisms for addressing meter defects or failures.

The public and stakeholders are invited to comment on the draft by July 15, 2024.

Earlier this year, TNERC unveiled forecasting, scheduling, and deviation settlement and related matters for wind and solar generation regulations in 2024. Last year, it increased the retail tariffs for 2023-24.