Interest on interim tariff excess is not payable absent statutory basis, even on equitable or restitutory grounds.

Excess tariff amounts collected by a generating company during the interim period before final tariff determination were held not to attract interest under Section 62(6) of the Electricity Act, 2003, because that provision applies to recovery beyond the tariff finally determined under the statutory process and does not create a separate right to interest. Interest also could not be awarded on equitable or restitutory grounds, as the prevailing tariff regime contained no express right to such relief and the later regulatory amendment could not operate retrospectively. The tariff differential remained adjustable, but no interest was payable for the intervening period.

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Issues: (i) Whether excess amounts collected by the generating company during the interim period, before final tariff determination, were recoverable by the beneficiaries with interest under Section 62(6) of the Electricity Act, 2003; (ii) Whether interest could be awarded on such differential amounts on principles of justice, equity, fair-play or restitution.

Issue (i): Whether excess amounts collected by the generating company during the interim period, before final tariff determination, were recoverable by the beneficiaries with interest under Section 62(6) of the Electricity Act, 2003.

Analysis: Section 62(6) applies where a licensee or generating company recovers an amount exceeding the tariff determined under Section 62. The provision is linked to the final tariff determined under the statutory process and does not create a separate right to interest merely because an interim tariff later stands reduced. The interim continuance of the existing tariff under the governing notifications and regulations did not contain any express provision for interest on the differential amount, and the later introduction of Regulation 5A could not operate retrospectively.

Conclusion: The claim for interest under Section 62(6) was not maintainable and was rightly rejected.

Issue (ii): Whether interest could be awarded on such differential amounts on principles of justice, equity, fair-play or restitution.

Analysis: Interest by way of equity or restitution is available only where the legal framework, contract, usage, or substantive law supports such relief, or where equitable jurisdiction is attracted by the circumstances. Here, the tariff was charged in accordance with the then-prevailing notifications, the beneficiaries were not compelled to pay the amounts by force or coercion, and the subsequent refund or adjustment did not disclose unjust enrichment of the generating company. The later regulatory amendment itself showed that no such right existed earlier. The equitable principles relied on could not override the absence of a statutory or contractual basis for interest.

Conclusion: Interest could not be awarded on equitable or restitutory grounds.

Final Conclusion: The challenge to the award of interest succeeded, and the contrary claims of the electricity boards failed; the tariff differential remained adjustable, but no interest was payable for the intervening period.

Ratio Decidendi: Where a statute or governing tariff regime does not expressly provide for interest on excess amounts collected pending final tariff determination, interest cannot be imposed by invoking equity, fairness or restitution alone.

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