Electricity Act (36 of 2003) , S.62— Income-Tax Act (43 of 1961) , S.32, S.295— Income-Tax Rules (1962) , R.5— Procurement of power by distribution licensee - Determination of tariff - Legality - Plea of distribution licensee GUVNL that respondents were estopped from seeking project-wise determination of tariff by ERC having willingly signed PPAs at tariff fixed for wind energy projects availing accelerated depreciation - Distribution licensee being an instrumentality of State is bound by policy directives of the State and cannot advance commercial considerations in isolation thereof on par with a private party - Distribution licensee had failed to obtain commitments from respondents that they would only avail accelerated depreciation at the time they had to choose that option - Distribution licensee had no indefeasible right to bind respondents to a tariff which was applicable only to such wind energy projects that availed accelerated depreciation - Tariff determined by ERC had no application to a wind energy project that did not avail accelerated depreciation - Distribution licensee could not apply the wholly inapplicable tariff to respondent companies which, admittedly, did not avail accelerated depreciation - Determination of tariff was not interfered with. AIR 2016 SC 698-DistinguishedAIR 2016 SC 5580-Relied on (Para 16 17 ....