Holding

Depreciation for tariff purposes is confined to the period approved in the PPA and cannot be recovered beyond the operational period, as consumer welfare under s.61(d) of the Electricity Act overrides the technical useful life of the asset.

Summary

The Delhi Electricity Regulatory Commission (Commission) approved a power purchase agreement (PPA) for the Rithala Combined Cycle Power Plant with a six‑year operational period, after which the plant ceased supplying electricity in March 2018. Tata Power Delhi Distribution Limited (TPDDL) later sought to recover the remaining capital cost of the plant by claiming depreciation over its technical useful life of fifteen years, invoking Regulation 6.32 of the 2011 DERC Regulations. The Appellate Tribunal for Electricity (APTEL) allowed this claim, setting aside the Commission’s order that limited depreciation to the six‑year period. The Supreme Court held that tariff determination must balance cost recovery with consumer welfare, and that depreciation cannot be charged beyond the period approved in the PPA. It interpreted Regulation 6.32 harmoniously with Regulation 4.1 and Section 61(d) of the Electricity Act, concluding that the generating utility does not have an absolute right to recover depreciation when the asset is no longer supplying power. Consequently, the Court set aside the APTEL judgment and restored the Commission’s order, limiting depreciation to the six‑year operational period.

Issues considered

Whether depreciation under the applicable tariff regulations must necessarily be allowed over the entire technical useful life of an asset irrespective of the period during which the asset is actually utilised for supply of electricity?
Whether Regulation 6.32 of the 2011 DERC Regulations confers an absolute right upon the generating utility to recover entire capital cost over the useful life of the asset, even where the asset ceases to supply electricity to the consumer?
Whether the APTEL erred in law in disregarding the regulatory framework and approval conditions which limited the operational and recovery period of the Plant to six years?

Legislation cited

Code of Civil Procedure, 1908
Electricity Act, 2003s. 61(d), s. 62

Headnote

Issue for Consideration Whether the depreciation under the applicable tariff regulations must necessarily be allowed over the entire technical useful life of an asset irrespective of the period during which the asset is actually utilised for supply of electricity; 2011 Regulations confers an absolute right upon the generating utility to recover entire capital cost over the useful life of the asset, even where the asset ceases to supply electricity to the consumer; whether the APTEL erred in law in disregarding the regulatory framework and approval

Subjects

depreciationtariff determinationconsumer welfarepower purchase agreementgenerating utilitytechnical useful lifeelectricity regulationDERC RegulationsAPTELDelhi Electricity Regulatory Commissioncapital cost recovery

Judgment

[2026] 5 S.C.R. 441 : 2026 INSC 461

Delhi Electricity Regulatory Commission
v.
Tata Power Delhi Distribution Limited
(Civil Appeal No. 6388 of 2025)
07 May 2026
[Pamidighantam Sri Narasimha and Alok Aradhe,* JJ.]

Issue for Consideration
Whether the depreciation under the applicable tariff regulations
must necessarily be allowed over the entire technical useful life
of an asset irrespective of the period during which the asset is
actually utilised for supply of electricity; whether Regulation 6.32
of 2011 Regulations confers an absolute right upon the generating
utility to recover entire capital cost over the useful life of the asset,
even where the asset ceases to supply electricity to the consumer;
whether the APTEL erred in law in disregarding the regulatory
framework and approval conditions which limited the operational
and recovery period of the Plant to six years.

Headnotes†
Electricity Act, 2003 – ss.61(d), 62 – DERC (Terms and
Conditions for Determination of Generation Tariff) Regulations,
2011 – Regulations 6.30-6.32, 4.1 – APTEL set aside the order
passed by the Delhi Electricity Regulatory Commission and
directed that entire capital cost of Rithala Combined Cycle
Power Plant at Rithala, Delhi (the Plant) be recovered through
depreciation over a period of fifteen years notwithstanding the
admitted fact that the Plant ceased to supply electricity to the
consumers from and after March-2018 – Challenge to – Whether
the depreciation under the applicable tariff regulations must
necessarily be allowed over the entire technical useful life of
an asset irrespective of the period during which the asset is
actually utilised for supply of electricity:
Held: Tariff determination is not merely a mathematical exercise
but a regulatory balancing act – The object of enabling reasonable
cost recovery for utilities must be weighed against and calibrated
with, paramount obligation to safeguard consumer interest – In
* Author
442 [2026] 5 S.C.R.

Supreme Court Reports

the instant case, admittedly, electricity has not been supplied to
the consumers beyond March-2018 – The consumers cannot be
required to pay for a service which they no longer received – Under
the PPA, TPDDL (Tata Power Delhi Distribution Limited) had to
supply electricity only for a period of six years – The Commission
had clarified to the Managing Director of TPDDL that the plant could
be treated as a merchant generator which is free to sell the power
anywhere other than to the distribution utilities in Delhi or outside
the State or to captive consumers within the State – There was no
legal impediment to either sale of the Plant or sale of electricity as
a merchant generator – Therefore, TPDDL cannot be permitted to
burden the consumers with tariff charges beyond March-2018 –
Therefore, the first substantial question of law is answered in the
negative – Impugned judgment passed by the APTEL is set aside,
order passed by the Commission is restored. [Paras 20, 23]

Electricity Act, 2003 – ss.61(d), 62 – DERC (Terms and
Conditions for Determination of Generation Tariff) Regulations,
2011 – Regulations 6.30-6.32, 4.1 – Whether Regulation 6.32 of
2011 Regulations confers an absolute right upon the generating
utility to recover entire capital cost over the useful life of the
asset, even where the asset ceases to supply electricity to
the consumer:
Held: No – Regulation 6.32 of 2011 Regulations prescribes the
methodology of calculating depreciation over the useful life of
the asset – No provision has to be read in isolation – Regulation
6.32 of 2011 Regulations must be construed harmoniously with
Regulation 4.1 of 2011 Regulations, which mandates that the tariff
for supply of electricity by a generating company to a distribution
licensee is to be determined in accordance with PPA or any other
arrangement for such period as may be approved or adopted by the
Commission, to the extent of existing installed capacity contained
in the PPA – Regulation 4.1 of 2011 Regulations confines tariff
entitlement to the period approved in the PPA – The order dated
31.08.2017 fixed the operational and recovery framework of the
plant up to March-2018 – The 2011 Regulations have to be read in
conjunction with s.61(d) of the 2003 Act which places the consumer
interest at the centre of tariff Regulation – Thus, Regulation 6.32 of
the 2011 Regulations does not, and cannot, override the broader
statutory and regulatory framework and the same does not confer
[2026] 5 S.C.R. 443

Delhi Electricity Regulatory Commission v.
Tata Power Delhi Distribution Limited

an absolute and unconditional right upon the generating utility to
recover depreciation from the consumers even for a period when
the asset is free to supply electricity. [Para 21]

Electricity Act, 2003 – ss.61(d), 62 – DERC (Terms and
Conditions for Determination of Generation Tariff) Regulations,
2011 – Whether the APTEL erred in law in disregarding the
regulatory framework and approval conditions which limited
the operational and recovery period of the Plant to six years:
Held: GNCTD granted permission on a temporary basis for
a period 5 to 6 years – The TPDDL was directed to obtain all
necessary regulatory approvals before commencing generation –
The Commission in its order dated 31.08.2017, which was not
challenged by TPDDL, approved the PPA only for a period of six
years from the date of commercial operation till March-2018 –
APTEL ought to have appreciated that distinction between 15
years technical useful life and 6 years regulatory recovery period
is not merely semantic but the tariff framework drew the distinction
clearly – APTEL’s approach is inconsistent with the order dated
31.08.2017, which was accepted by TPDDL and had attained
finality – The True-up proceedings are intended to give effect to
tariff framework and not to reopen or reconfigure it – APTEL erred,
therefore, in disregarding the regulatory framework and conditions
of approval – Therefore, the third substantial question of law, is
answered in the affirmative – The substantial questions of law which
arise for consideration in this appeal, are answered in favour of the
Commission and against the TPDDL – Impugned judgment dated
10.02.2025 passed by the APTEL is set aside and order dated
11.11.2019 passed by the Commission is restored. [Paras 22, 23]

Electricity Act, 2003 – s.61 – Tariff Determination – Consumer
welfare, a central and guiding statutory principle:
Held: s.61 of the 2003 Act governs the determination of tariff – s.61(d)
specifically provides that in specifying the terms and conditions
for the determination of tariff, the Appropriate Commission shall
be guided, inter alia, by the object of safeguarding consumers’
interests and at the same time, recovery of the cost of electricity
in a reasonable manner – This provision establishes consumer
welfare not as a peripheral consideration but as a central and
guiding statutory principle in tariff determination. [Para 15]
444 [2026] 5 S.C.R.

Supreme Court Reports

Case Law Cited
BSES Rajdhani Power Ltd. & Anr. v. Union of India & Ors.,
2025 SCC OnLine SC 1637 – referred to.

List of Acts
Electricity Act, 2003, DERC (Terms and Conditions for Determination
of Generation Tariff) Regulations, 2011; Code of Civil Procedure,
1908.

List of Keywords
Depreciation under applicable tariff regulations; Entire technical
useful life of an asset; Rithala Combined Cycle Power Plant at
Rithala, Delhi; Plant ceased to supply electricity to the consumers;
Sections 61(d), 62, Electricity Act, 2003; Generating utility; Entire
capital cost; Useful life of the asset.

Case Arising From
CIVIL APPELLATE JURISDICTION: Civil Appeal No. 6388 of 2025
From the Judgment and Order dated 10.02.2025 of the Appellate
Tribunal for Electricity at New Delhi in AN No. 33 of 2020.

Appearances for Parties
Advs. for the Appellant(s):
Jayant K. Mehta, Sr. Adv., Dhananjay Baijal, Ms. Mansvini Jain,
Tilak Singh.
Advs. for the Respondent(s):
Kapil Sibal, Sr. Adv., Amit Kapur, Anupam Varma, Rahul Kinra, Aditya
Gupta, Girdhar Gopal Khattar, Yash Srivastava, Pukhrambam
Ramesh Kumar, Karun Shamra, Ms. Anupama Ngangom,
Ms. Rajkumari Divyasana.

Judgment / Order of the Supreme Court

Judgment

Alok Aradhe, J.

1. This appeal under Section 125 of the Electricity Act, 2003, (2003 Act)
preferred by Delhi Electricity Regulatory Commission (Commission)
[2026] 5 S.C.R. 445

Delhi Electricity Regulatory Commission v.
Tata Power Delhi Distribution Limited

challenges the correctness and legality of the judgment and order
dated 10.02.2025 passed by the Appellate Tribunal for Electricity
(APTEL). By the impugned judgment, APTEL has set aside the
order dated 11.11.2019 passed by the Commission and issued the
direction that entire capital cost of Rithala Combined Cycle Power
Plant at Rithala, Delhi (the Plant) be permitted to be recovered
through depreciation over a period of fifteen years notwithstanding
the admitted fact that the Plant ceased to supply electricity to the
consumers from and after March-2018.
2. The facts giving rise to this litigation though substantially not in dispute,
are required to be set out, in order to appreciate the competing legal
submissions advanced before us.

FACTUAL MATRIX
3. The respondent, Tata Power Delhi Distribution Limited (TPDDL) is a
joint venture entity between the Tata Power Company Limited and
Delhi Power Company Limited. On 11.06.2007, TPDDL moved a
proposal for allotment of land at Rithala for setting up a temporary
108-megawatts Gas-based Power Plant with operational tenure
expressly limited to 5 to 6 years, following which the land would
revert to the Delhi Development Authority (DDA). The genesis of
the project lay in the pressing and urgent need to augment power
supply in the National Capital Territory of Delhi in the lead-up to the
Commonwealth Games 2010. The Plant was conceived as a short-
term measure to address peak demand and accordingly, approval
was structured within a limited operational horizon. On 24.07.2007,
TPDDL addressed the letter to the DDA seeking change of land use
specifically for a short-term 5 to 6 years operational span of the Plant.
4. On 17.05.2008, TPDDL intimated Commission of its intention to
establish and operate the Plant. The Commission sometime in
April-2009 granted in principle approval for the scheme based on
TPDDL’s proposal submitted in the year 2008. On 27.07.2009,
Generation and Distribution divisions of TPDDL executed an intra
company “Terms and conditions for sale and purchase of power
for the Plant”. The TPDDL on 21.08.2009 filed a petition namely,
petition no. 11 of 2009, before the Commission under Section 62
read with Section 86 (1)(b) of the 2003 Act, seeking approval of the
said terms and conditions. A second petition namely, petition no. 7
of 2010, was filed on 26.02.2010, seeking approval for the use of
446 [2026] 5 S.C.R.

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6 acres land for setting up 108-megawatts Power Generation Plant
at Rithala, New Delhi. A third petition namely, petition no. 6 of 2013,
was filed by TPDDL on 23.11.2012, seeking determination of the
final generation tariff from the Plant.
5. The Plant achieved commercial operation in open cycle mode
on 04.02.2011 and in combined cycle mode on 04.09.2011. The
Commission disposed of all the three petitions filed by TPDDL by a
common order dated 31.08.2017, the details of which are as follows:
(i) The Commission allowed petition no. 11 of 2009 to the extent of
permission granted by Government of National Capital Territory
of Delhi (GNCTD) for a period of six years from the year of
commissioning of the Plant in combined cycle mode, thereby
fixing the operation and supply period up to March-2018.
(ii) The Commission allowed petition no. 7 of 2010 subject to the
condition that any profits from the Plant would be governed
by provisions of DERC (Treatment of Income from Other
Business of Transmission Licensee and Distribution Licensee)
Regulations, 2005.
(iii) The Commission allowed petition no. 6 of 2013 and approved
the fixed charges and operational parameters required for
computation of energy charges and directed the TPDDL to
file true-up petitions for finalisation of generation tariff for the
respective years.
6. The Commission by its order dated 31.08.2017, determined the
capital cost of the Plant at ₹197.70 crores after applying appropriate
benchmarking and prudence checks as against the TPDDL’s claimed
capital cost of ₹320.17 crores. It is noteworthy that the said capital
cost determination was made in the backdrop of six years operational
framework. The Commission accepted a technical useful life of the
Plant of fifteen years based on experts certification, and it restricted
the operational and tariff recovery framework to a period of six years.
The Plant was thus allowed to operate for supply purposes only till
March-2018. The TPDDL did not challenge the aforesaid order by
way of an appeal and therefore the order dated 31.08.2017 has
become final and binding inter-parties.
7. Subsequently, TPDDL filed a petition namely, petition no. 51 of 2017,
seeking true-up of expenditure for Financial Years 2010-2011 to 2016-
[2026] 5 S.C.R. 447

Delhi Electricity Regulatory Commission v.
Tata Power Delhi Distribution Limited

2017 and the annual requirements for Financial Year 2017-2018. The
Commission, by an order dated 11.11.2019, allowed depreciation at
the rate of 6% per annum in respect of the Plant only up to Financial
Year 2017-2018 resulting in cumulative depreciation of ₹83.34 crores.
The remaining capital cost of approximately ₹94.59 crores together
with carrying cost, was not allowed to be passed through in tariff,
on the ground that Plant has ceased to supply electricity to the
consumers after March-2018.
8. The aforesaid order of the Commission was challenged by TPDDL
in an appeal. The APTEL by an order dated 10.02.2025 inter alia
held that the Commission itself had fixed the useful life of the Plant
at fifteen years and had computed the capital cost on that basis.
Therefore, the depreciation cost cannot be restricted only to six
years. The APTEL further held that Regulation 6.32 of the DERC
(Terms and Conditions for Determination of Generation Tariff)
Regulations, 2011 (2011 Regulations) mandated depreciation over
the useful life and did not admit of any exception. The APTEL,
therefore, set aside the order of the Commission and remanded
the matter to it with a direction to allow recovery of entire capital
cost of the Plant by way of depreciation over the useful life of the
Plant for fifteen years.
9. Aggrieved by the said judgment the Commission has preferred the
present appeal.

SUBMISSIONS
10. Learned senior counsel for the Commission submitted that APTEL
erred in not appreciating that TPDDL cannot recover the capital cost
of the Plant either from the distribution licensee or from the retail
consumers of Delhi, in respect of electricity not supplied and to fasten
the liability on the consumers for a period beyond March-2018 is
contrary to Section 61 (d) of the 2003 Act. It is contended that APTEL
misapplied Regulation 6.32 of 2011 Regulations and ought to have
appreciated that TPDDL was free to exploit the Plant beyond six
years to recover its capital cost. It is, therefore, submitted that the
impugned order be set aside and the appeal be allowed.
11. Learned senior counsel for the TPDDL, on the other hand, submitted
that TPDDL is entitled to recover depreciation in terms of Regulation
448 [2026] 5 S.C.R.

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6.32 of 2011 Regulations, as the same does not restrict depreciation
only to the operational life or the duration of the Power Purchase
Agreement (PPA). It is contended that TPDDL is only seeking to
recover balance recovery of depreciable capital cost of the Plant.
It is urged that Commission must abide by and implement the
directions of APTEL to secure accountability and disproportionate
increase and long pending regulatory asset depict a regulatory
failure which has serious consequences on all stakeholders and
the ultimate burden is only on the consumer1. It is urged that
the order of the APTEL does not call for any interference in this
appeal.

ISSUES
12. We have considered the rival submissions on both sides and have
perused the record. Section 125 of the 2003 Act provides for a
remedy of appeal to an aggrieved person from the decision or order
of APTEL to this Court, on any one or more of the grounds specified
in Section 100 of the Code of Civil Procedure, 1908.
13. Upon consideration of the pleadings, the record of the proceedings
before the Commission and APTEL, and the submissions of learned
counsel for the parties, following substantial questions of law arise
for determination in this appeal:
(i) Whether the depreciation under the applicable tariff regulations
must necessarily be allowed over the entire technical useful life
of an asset irrespective of the period during which the asset is
actually utilised for supply of electricity?
(ii) Whether Regulation 6.32 of 2011 Regulations confers an
absolute right upon the generating utility to recover entire capital
cost over the useful life of the asset, even where the asset
ceases to supply electricity to the consumer?
(iii) Whether the APTEL erred in law in disregarding the regulatory
framework and approval conditions which limited the operational
and recovery period of the Plant to six years?

1 BSES Rajdhani Power Ltd. & Anr. v. Union of India & Ors., 2025 SCC OnLine SC 1637
[2026] 5 S.C.R. 449

Delhi Electricity Regulatory Commission v.
Tata Power Delhi Distribution Limited

STATUTORY FRAMEWORK
14. Before proceeding further, it is useful to set out the statutory and
regulatory provisions that have bearing on the questions which arise
for consideration in this appeal.
15. Section 61 of the 2003 Act governs the determination of tariff.
Section 61(d) specifically provides that in specifying the terms and
conditions for the determination of tariff, the Appropriate Commission
shall be guided, inter alia, by the object of safeguarding consumers’
interests and at the same time, recovery of the cost of electricity in a
reasonable manner. This provision establishes consumer welfare not
as a peripheral consideration but as a central and guiding statutory
principle in tariff determination.
16. Section 62 of the 2003 Act empowers the Commission to determine
tariff for supply of electricity by a generating company to a distribution
licensee, in accordance with the provisions of the 2003 Act and the
Regulations made thereunder.
17. Regulations 6.30 to 6.32 of the DERC (Terms and Conditions for
Determination of Generation Tariff) Regulations, 2011 provides as
follows:
“6.30 Depreciation shall be calculated for each year of
the Control Period, on the amount of Capital Cost of the
Fixed Assets as admitted by the Commission; Provided
that depreciation shall not be allowed on assets funded
by any capital subsidy/grant.
6.31 Depreciation for each year of the Control Period shall
be determined based on the methodology as specified in
these Regulations along with the rates and other terms
specified in Appendix-1 of these Regulations.
6.32 Depreciation shall be calculated annually, based on
the straight line method, over the useful life of the asset.
The base value for the purpose of depreciation shall be
capital cost of the asset as admitted by the Commission.
Provided that, the remaining depreciable value as on 31st
March of the year closing after a period of 12 years from
the date of commercial operation shall be spread over the
balance useful life of the assets.”
450 [2026] 5 S.C.R.

Supreme Court Reports

18. Regulation 4.1 of the 2011 Regulations mandates that the tariff for
supply of electricity by the generating company to the distribution
licensee shall be in accordance with the PPA or any other
arrangement for such period as may be approved or adopted by
the Commission, to the extent of the existing installed capacity as
contained in the PPA.

ANALYSIS AND FINDINGS

Question No. (i)
19. The Commission while computing the capital cost of the Plant for
determination of final generation tariff, by an order dated 31.08.2017,
found that useful life of the Plant is fifteen years. However, the
Commission vide order dated 31.08.2017, approved the PPA which
restricted the period of operation and supply up to March-2018, i.e.,
for a period of six years. Admittedly, a sum ₹83.34 crores has been
approved as depreciation for the aforesaid period of six years.
20. The tariff determination is not merely a mathematical exercise but
a regulatory balancing act. The object of enabling reasonable cost
recovery for utilities must be weighed against and calibrated with,
paramount obligation to safeguard consumer interest. In the instant
case, admittedly, electricity has not been supplied to the consumers
beyond March-2018. The consumers cannot be required to pay for a
service which they no longer received. Under the PPA, TPDDL had
to supply electricity only for a period of six years. It is also pertinent
to note that the Commission on 04.09.2012, had clarified to the
Managing Director of TPDDL that the plant could be treated as a
merchant generator which is free to sell the power anywhere other
than to the distribution utilities in Delhi or outside the State or to
captive consumers within the State. There was no legal impediment to
either sale of the Plant or sale of electricity as a merchant generator.
Therefore, TPDDL cannot be permitted to burden the consumers with
tariff charges beyond March-2018. Therefore, the first substantial
question of law is answered in the negative.

Question No. (ii)
21. Regulation 6.32 of 2011 Regulations prescribes the methodology
of calculating depreciation over the useful life of the asset. It is a
settled canon of statutory interpretation that no provision has to
[2026] 5 S.C.R. 451

Delhi Electricity Regulatory Commission v.
Tata Power Delhi Distribution Limited

be read in isolation. Regulation 6.32 of 2011 Regulations must be
construed harmoniously with Regulation 4.1 of 2011 Regulations,
which mandates that the tariff for supply of electricity by a generating
company to a distribution licensee is to be determined in accordance
with PPA or any other arrangement for such period as may be
approved or adopted by the Commission, to the extent of existing
installed capacity contained in the PPA. Regulation 4.1 of 2011
Regulations confines tariff entitlement to the period approved in the
PPA. The order dated 31.08.2017 fixed the operational and recovery
framework of the plant up to March-2018. The 2011 Regulations
have to be read in conjunction with Section 61(d) of the 2003 Act
which places the consumer interest at the centre of tariff Regulation.
Thus, Regulation 6.32 of the 2011 Regulations does not, and cannot,
override the broader statutory and regulatory framework and the
same does not confer an absolute and unconditional right upon the
generating utility to recover depreciation from the consumers even
for a period when the asset is free to supply electricity. For the
aforementioned reasons, the substantial question of law no. (ii) is
also answered in the negative.

Question No. (iii)
22. The GNCTD granted permission on a temporary basis for a period 5
to 6 years. The TPDDL was directed to obtain all necessary regulatory
approvals before commencing generation. The Commission in its
order dated 31.08.2017, which was not challenged by TPDDL,
approved the PPA only for a period of six years from the date of
commercial operation till March-2018. The APTEL ought to have
appreciated that distinction between 15 years technical useful life
and 6 years regulatory recovery period is not merely semantic
but the tariff framework drew the distinction clearly. The APTEL’s
approach is inconsistent with the order dated 31.08.2017, which
was accepted by TPDDL and had attained finality. The True-up
proceedings are intended to give effect to tariff framework and
not to reopen or reconfigure it. The APTEL erred, therefore, in
disregarding the regulatory framework and conditions of approval.
Therefore, the third substantial question of law, is answered in the
affirmative.
23. For the foregoing reasons, the substantial questions of law which
arise for consideration in this appeal, are answered in favour of
452 [2026] 5 S.C.R.

Supreme Court Reports

the Commission and against the TPDDL. The impugned judgment
dated 10.02.2025 passed by the APTEL is set aside and order dated
11.11.2019 passed by the Commission is restored.
24. In the result, appeal is allowed. There shall be no order as to costs.

Result of the case: Appeal allowed.

†
Headnotes prepared by: Divya Pandey