The entitlement of a generating utility to recover the remaining capital cost of a power plant through consumer tariff depreciation over its technical life of 15 years, despite the plant explicitly ceasing operations and electricity supply after an approved 6-year regulatory period. Appeal allowed. The Supreme Court set aside the Appellate Tribunal for Electricity (APTEL) order and restored the Delhi Electricity Regulatory Commission’s (DERC) order, holding that consumers cannot be burdened with depreciation costs for a period where no electricity was supplied.
Details
1. Factual Background
- Project Conception: In 2007, Tata Power Delhi Distribution Limited (TPDDL/Respondent) moved a proposal to set up a temporary 108-MW gas-based power plant at Rithala, Delhi, to meet immediate peak demands for the upcoming Commonwealth Games 2010. TPDDL explicitly requested land from the Delhi Development Authority (DDA) on a short-term basis, limiting the operational horizon to 5 to 6 years.
- Commercial Operation & Approvals: The Rithala plant achieved full combined-cycle commercial operation on September 4, 2011. DERC (Appellant) passed a common order on August 31, 2017, approving the internal Power Purchase Agreement (PPA) and fixing the regulatory operation and supply period up to March 2018 (a total of 6 years).
- Capital Cost and Useful Life: In the same 2017 order, DERC checked expenditures and fixed the plant’s capital cost at ₹197.70 crores. While experts certified the technical useful life of the plant to be 15 years, the regulatory recovery through consumer tariffs was strictly bound to the 6-year operational timeline. TPDDL did not appeal this decision, allowing it to become final.
- The True-Up Dispute: TPDDL subsequently filed a true-up petition seeking financial finalisation. On November 11, 2019, DERC allowed depreciation up to March 2018, which accumulated to ₹83.34 crores. DERC refused to pass the remaining capital cost of ₹94.59 crores onto the consumers, given that the plant ceased supplying them power after March 2018.
2. Lower Tribunal’s Ruling
TPDDL appealed DERC’s decision to the Appellate Tribunal for Electricity (APTEL). On February 10, 2025, APTEL set aside DERC’s order and ruled in favor of TPDDL. APTEL reasoned that because the plant’s useful life was acknowledged as 15 years and capital cost was computed on that basis, Regulation 6.32 of the DERC Tariff Regulations mandated that depreciation be fully recovered over those 15 years without exception. DERC challenged this decision before the Supreme Court.
3. Arguments Raised
- On Behalf of the Commission (DERC): It was argued that APTEL erred by allowing a utility to pass down capital costs to retail consumers for a period when no electricity was supplied, violating Section 61(d) of the Electricity Act, 2003. Furthermore, DERC had already clarified that TPDDL was free to operate the plant as a “merchant generator” after March 2018 to sell power outside the consumer network and recover its balance.
- On Behalf of the Utility (TPDDL): TPDDL contended that Regulation 6.32 mandates depreciation over the entire useful life of an asset and does not tie it strictly to active PPA durations. They asserted that denying the balance recovery creates massive, unrecovered regulatory assets that destabilize the financial health of power distribution systems.
4. Key Legal Issues & Findings of the Supreme Court
A. Consumer Interest vs. Cost Recovery
The Court emphasized that under Section 61(d) of the Electricity Act, 2003, safeguarding consumer interest is a core statutory principle and not a peripheral concern. Tariff determination requires a regulatory balance. Forcing retail consumers to pay for depreciation costs on a plant from which they receive absolutely zero electricity violates this statutory protection.
B. Harmonious Interpretation of Regulations
The Court rejected APTEL’s isolated reading of Regulation 6.32 (which outlines straight-line depreciation over useful life). It ruled that Regulation 6.32 must be read harmoniously with Regulation 4.1, which strictly limits tariff entitlements to the timeframe adopted and approved in the PPA. Because the approved PPA ran for only 6 years (ending in March 2018), the right to recover depreciation via consumer tariffs legally expired at that same mark.
C. Finality of Regulatory Approvals
The Supreme Court pointed out that the distinction between a 15-year technical life and a 6-year regulatory recovery timeline was clearly settled in DERC’s 2017 order. Since TPDDL chose not to appeal that order, it attained finality. True-up proceedings are designed strictly to mathematically reconcile approved frameworks, not to reopen settled conditions or fundamentally reconfigure risk allocations.
Additionally, because the regulator explicitly permitted TPDDL to transition the facility into a merchant plant or sell the asset after March 2018, there were alternative avenues to recover capital without burdening captive consumers.
5. Final Direction
The substantial questions of law were answered in favor of the Commission. The Supreme Court set aside APTEL’s judgment dated February 10, 2025, and fully restored DERC’s true-up order dated November 11, 2019. The appeal was allowed with no orders as to costs.
2026 INSC 461
Delhi Electricity Regulatory Commission V. Tata Power Delhi Distribution Limited (D.O.J. 07.05.2026)




