Captive power plant rules: Supreme Court tightens ownership test

You own 26% of a power plant at year-end. The Supreme Court says that's not enough—

The clock reads March 31. Your auditor's pen ticks the box on the compliance sheet. The cross-subsidy surcharge (the extra charge industrial consumers pay to subsidise residential electricity tariffs) is waived for the entire year. On April 1, you sell your stake. The stack of conflicting tribunal orders on the bench rustles as the Court just ruled that this game is over.

On a Monday morning in October 2023, a two-judge bench of the Supreme Court—Justice Sanjiv Khanna and Justice M.M. Sundresh—handed down a judgment that rewrote the rules for every company in India that owns a captive power plant. The case had travelled through the Appellate Tribunal for Electricity (APTEL) three times, producing three conflicting decisions. The question at its heart was deceptively simple: what does it actually mean to own a power plant?

The answer, the Court ruled, is that owning 26% of a captive generating plant (CGP) isn't a snapshot—it's a movie. You have to own that stake every single day of the financial year, not just on the day the auditor checks the books. And if you're a Special Purpose Vehicle (a company set up for a single project), you get no special treatment. You're treated exactly like any other group of owners.

When the electricity bill became a legal battlefield

The dispute began with a simple commercial reality. Companies that set up captive power plants get a significant financial benefit: they don't have to pay cross-subsidy surcharges when they wheel their power through the state grid. For a paper mill or a steel plant running its own generator, that exemption can mean crores in savings every year.

But the Electricity Act, 2003, and the Electricity Rules, 2005, set strict conditions for who qualifies as a captive user. Rule 3(1)(a) says that to be a CGP, the owners must collectively hold at least 26% of the plant's equity and must consume at least 51% of the electricity it generates. The second proviso to that rule adds a proportionality requirement: each owner's share of consumption must roughly match their share of ownership.

The trouble started when distribution companies—the state-owned entities that buy and sell electricity—began challenging captive power plant claims. They argued that companies were gaming the system: holding 26% ownership for a single day at year-end, or setting up SPVs to bypass the proportionality requirement. Three different APTEL benches gave three different answers.

The three judgments that couldn't agree

The first decision, Kadodara Power in September 2009, held that the proportionality requirement applied to all captive users, including SPVs. It also said that ownership had to be maintained continuously. The bench's reasoning was dense, its conclusions firm—but it would not be the last word.

Then came Tamil Nadu Power in June 2021. That bench declared Kadodara Power had been decided incorrectly—that it was per incuriam (decided without regard to binding precedent) on several points. It said year-end verification was sufficient, and that SPVs were exempt from the proportionality test. The calculator on the registrar's desk seemed to mock the arithmetic: if year-end was enough, the numbers could be made to say anything.

A few months later, Sai Wardha in November 2021 substantially agreed with Tamil Nadu Power. The law was now a mess. Distribution companies were paying out crores in surcharge exemptions based on conflicting rulings. The Supreme Court had to step in.

Why year-end verification wasn't enough

The distribution companies—led by Dakshin Gujarat Vij Company Limited—argued that the whole point of the captive power plant regime was to ensure genuine self-generation. If a company could hold 26% ownership for one day and then sell its stake, the plant was effectively a commercial generator using a captive label to avoid surcharges.

The Supreme Court agreed. It held that the minimum 26% ownership under Rule 3(1)(a)(i) must be maintained continuously throughout the financial year. The Court said that verifying ownership only at year-end would defeat the purpose of the rule. A company could hold 26% on March 31, claim the exemption for the entire year, and sell its stake on April 1. That wasn't captive generation—it was regulatory arbitrage (exploiting a gap in the rules for financial advantage).

The Court introduced a practical solution: the weighted average method. Where shareholding or consumption fluctuates during the year, the compliance must be calculated using a weighted average, not a simple year-end figure. This means each owner's consumption is measured proportionally across the entire period they held their stake.

The proportionality math that changed everything

Under the second proviso to Rule 3(1)(a), the Court laid down a precise formula. Since the minimum ownership is 26% and the minimum consumption is 51%, each 1% of shareholding requires at least 1.96% of consumption (51 divided by 26). With the permitted ±10% variation, the range becomes 1.764% to 2.156%.

This isn't academic. Imagine a company that owns 30% of a captive plant. Its consumption must fall between 52.92% and 64.68% of the plant's output. If the company's factory runs a shift less one month, or a new machine draws more power than expected, the ratio can slip. Fall below that range, and the plant loses its captive status—meaning the company must pay the cross-subsidy surcharge it thought it had avoided. The calculator on the compliance officer's desk now has a new set of numbers to check, month after month.

Why SPVs got no special treatment

The most contested issue was whether Special Purpose Vehicles—companies set up solely to own and operate a generating station—were exempt from the proportionality requirement. The Tamil Nadu Power bench had said yes, relying on the wording of Rule 3(1)(b), which deals specifically with SPVs.

The Supreme Court rejected that reading. It held that an SPV under Rule 3(1)(b) is an 'association of persons' (a group of individuals or entities acting together) and must satisfy the same proportionality requirement under the second proviso to Rule 3(1)(a). The Court reasoned that allowing SPVs to bypass proportionality would create a massive loophole: companies could set up an SPV, hold 26% collectively, and then distribute consumption arbitrarily among themselves, defeating the entire purpose of the captive regime.

The judgment stated that a company set up as a Special Purpose Vehicle under Rule 3(1)(b) is an 'association of persons' and must satisfy the proportionality requirement under the second proviso to Rule 3(1)(a). This single sentence closed a door that had been left ajar for over a decade.

What the Court did with the conflicting decisions

The Supreme Court's operative order was surgical. It affirmed Kadodara Power on the two key issues: proportionality applies to all captive users, and SPVs are associations of persons subject to the same test. It overruled Tamil Nadu Power and Sai Wardha on year-end verification and the SPV exemption. And it established the weighted average method as the standard for calculating compliance when shareholding fluctuates.

The Court also clarified one more thing: a CGP does not lose its captive status simply because ownership is transferred. As long as the new owner meets the Rule 3 eligibility criteria, the plant remains a CGP. This was a significant relief for companies that restructure or sell stakes mid-year.

Why this matters for every captive power plant owner

For companies that operate captive power plants, this judgment changes compliance from a year-end exercise to a continuous obligation. The days of holding 26% for a single day are over. Every transfer of shares, every change in consumption patterns, must now be tracked and tested against the proportionality formula.

For distribution companies, the judgment provides a clear legal basis to challenge claims that were previously protected by conflicting tribunal rulings. Expect a wave of reassessments as state utilities review past exemptions.

THE PLAY: Audit your captive power plant's ownership and consumption data month-by-month, not year-by-year—if any month falls below the 1.764% to 2.156% range per 1% shareholding, you lose the exemption for that entire financial year.

The Court ended where it began: with a single question about what ownership means, and an answer that turned a snapshot into a movie.