The Tamil Nadu Electricity Regulatory Commission (TNERC) has approved an additional surcharge of ₹0.10 (~$0.00117)/kWh for open access consumers procuring power from sources other than the Tamil Nadu Power Distribution Corporation (TNPDCL), including third-party sellers and power exchanges.

Effective from April 1, 2025, to September 30, 2025, the surcharge applies to the actual energy drawn and aims to address TNPDCL’s stranded capacity and recover its fixed costs.

Background

TNPDCL filed a petition seeking directions from TNERC to determine the additional surcharge or open access consumers on the adjusted quantum of power purchased from April 1, 2025, to September 30, 2025.

The petitioner submitted that open access consumers purchasing power from other sources led to the underutilization of its contracted capacity, resulting in stranded fixed costs.

It highlighted that of its total contracted capacity of 23,959.86 MW, it experienced an average stranded capacity of 1,042.09 MW, of which 410.55 MW was due to open access consumers.

The petitioner reported fixed costs of ₹91.39 billion (~$1.06 billion) for the reference period and attributed ₹231.3 million (~$2.7 million) to open access-related stranded capacity. Using a methodology approved in earlier orders, the petitioner proposed a surcharge of ₹0.13 (~$0.00152)/kWh.

It also submitted state load dispatch center-certified 15-minute block data, fixed cost breakdowns, and auditor-certified financials to substantiate its claims. Some stakeholders objected to the methodology and data used.

Commission’s Analysis

TNERC upheld the petitioner’s methodology by referring to an older Appellate Tribunal for Electricity case.

The Commission also validated the data used by the petitioner and confirmed that 410.55 MW of capacity was stranded due to open access. It accepted the petitioner’s claim that ₹305.5 million (~$3.56 million) was recoverable from open access users after adjustments.

Additionally, the Commission emphasized that the methodology used by the petitioner must be followed for future surcharge filings and mandated strict compliance in data submissions and reporting.

TNERC approved a surcharge rate of ₹0.10 (~$0.00117)/kW, lower than the requested amount. This rate will apply to 2,287.14 million units (MU) of open access energy scheduled during the reference period.

In December 2024, TNERC issued an order setting the additional surcharge for open access consumers at ₹0.54 (~$0.0063)/kWh, effective from December 12, 2024, until March 31, 2025.

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