Grid Defaulters Face Scheduling Curbs Under CERC's Draft Grid Code Amendment
India's power regulator is tightening the rules on who pays when transmission corridors saturate, while still withholding the number that decides how much.
Power flows that breach a corridor's total transfer capability (TTC) will attract congestion charges under draft amendments to the Indian Electricity Grid Code. The Central Electricity Regulatory Commission (CERC) has left the charge itself to a separate order, and that order has not yet been issued.
Transmission Constraints Are Already Costing Clean Power
The draft arrives as grid bottlenecks begin to show up in generation data. India lost 300 million units of renewable electricity to transmission constraints in the first quarter of 2026, according to Ember.
Congestion charges are not new. CERC has priced corridor overloads since its 2009 congestion regulations, with the current rate of ₹5.45 per kWh unchanged since 2010. What the draft changes is where the mechanism lives and how firmly it is enforced.
Congestion Rules Move Into the Grid Code
Under the draft, published on September 21, grid operators must first issue a warning when flows cross available transfer capability. Charges apply only once flows exceed TTC, and entities must receive at least two clear time blocks of notice. The regional entities responsible for the overload pay within 10 days of the Regional Power Committee statement, with late payments accruing interest at 0.04% per day.
On price, the text is deliberately open. CERC says it will "by order specify the rate of congestion charge," and may apply different rates to all or part of a region. Until then, the 2009 rate and procedure continue.
Defaulters Lose Scheduling Access
The sharper change concerns payment discipline. An entity that leaves deviation settlement, congestion or reactive energy charges unpaid for 75 days after the account is issued, or fails to replenish its payment security on time, will have its scheduling regulated. If dues remain unpaid for a further two months, its short-term contracts under General Network Access are regulated entirely.
Storage Gets a Phased Route to Commissioning
The draft also sets a minimum trial-run size of 50 MW for standalone energy storage. Projects of 250 MW or more may commission in instalments of at least 50 MW, with no cap on the number of tranches. Power can be scheduled before commercial operation only after a successful trial run. Separate trial-run provisions apply to pumped storage.
The Price Signal Is the Unresolved Variable
The draft shifts risk in three directions. Storage developers gain the most immediate benefit, since phased commissioning lets revenue start before a full plant is complete. The 2,800 MWh of storage in Waaree's recent SECI award shows the scale of capacity now entering that pipeline. State utilities with chronic arrears face the most direct exposure, because scheduling curbs now attach to unpaid grid charges.
Renewable generators sit in the middle. In a March 2026 proposal, CERC suggested replacing the flat rate with 1.5 times the relevant reference charge rate, bounded between ₹3 and ₹10 per kWh. It also declined to exempt renewable generators, reasoning that congestion is a grid security issue regardless of fuel. Consultation on that proposal closed on April 6, but no final order has been located.
The result is a stricter enforcement framework without a settled price. A congestion charge only changes where developers build and when they dispatch if the rate is high enough to matter, and that figure remains unpublished.
What to Watch
Comments on the draft close on October 21, 2026. The more consequential decision is whether CERC finalises its March rate proposal alongside the amended Grid Code. If the ₹3 to ₹10 band is adopted without a renewable exemption, solar-heavy generators in congested corridors will carry a new line of dispatch risk. If it slips, the 2010 rate continues to govern a grid that looks very different from the one it was set for.
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