CEA Mandatory Storage for Solar, Wind Projects 2027

Quick Answer

Why This Matters for EPCs

India curtailed more than 8,133 GWh of solar generation in the first quarter of this financial year alone, enough to power roughly 1.4 million homes for a year, because the grid couldn't absorb the daytime surplus. This mandate is CEA's direct response, and if it lands anywhere close to the current draft, it changes what inverters and storage configurations get specified into any project targeting mid-2027 commissioning. The specifics are concrete enough to plan around now, and uncertain enough that you shouldn't treat any single detail as locked yet, especially not before the comment window closes.

What CEA Actually Proposed

The draft, formally the Central Electricity Authority (Technical Standards for Construction of Electric Plants and Electric Lines) 2nd Amendment Regulations, 2026, was published in the Gazette of India on September 3, 2026, issued under Section 177 of the Electricity Act, 2003. Two separate requirements sit inside it.

Under proposed Regulation 106B(20), renewable energy power plants commissioned on or after July 1, 2027 must have at least 15% of their inverters equipped with grid-forming control, technology that actively helps stabilize grid voltage and frequency rather than passively following it. Separately, every power conversion system used in a battery energy storage system must also have grid-forming control, regardless of the plant type it's attached to.

The second requirement is narrower in scope: ground-mounted solar and onshore wind power plants commissioned on or after July 1, 2027 must have co-located energy storage.

The Storage Formula, With the Actual Numbers

The capacity percentage doesn't change between phases, only the duration doubles. CEA has also explicitly reserved the right to modify either the grid-forming percentage or the storage capacity requirement "from time to time," meaning even the 15% and 10% figures shouldn't be treated as permanently fixed once finalized.

Timeline

Comments can be submitted by post to the Chief Engineer (Legal), Central Electricity Authority, Sewa Bhawan, R.K. Puram, New Delhi, or by email to celegal-cea@gov.in.

What's Genuinely Unclear: Does This Apply to Your Projects?

This is the question that matters most for Reslink's core audience, and current reporting doesn't give a clean answer either way, worth stating plainly rather than guessing.

Every source covering this draft frames the storage mandate specifically around "ground-mounted solar and onshore wind" projects, and every single worked example uses a 100 MW plant. That's a consistent signal the storage requirement is aimed at utility-scale generation, not rooftop or smaller distributed C&I systems.

The grid-forming inverter requirement is different. It's stated more broadly, applying to "renewable energy power plants" generally, without the same "ground-mounted" qualifier the storage rule carries. No source found gives a specific capacity threshold defining what counts as a covered "power plant" for this purpose, whether a 500 kW commercial rooftop system would be swept in, or whether there's an unstated size floor below which the requirement doesn't apply.

One data point worth knowing, though it may not directly govern this specific amendment: an earlier, separate CEA consultation from April 2026 proposed that systems of 50 MW and above face additional requirements including grid-forming inverter capability and black-start capability. That's a different document, and it's not confirmed whether that same threshold carries into this September 2026 amendment. Don't treat it as an answer, treat it as a reason to check directly rather than assume smaller systems are automatically exempt.

Common Mistakes to Avoid

• Assuming this is final law. It's a draft, open for comment until October 4, 2026, and CEA can still change the specific percentages before finalizing.
• Assuming the storage mandate applies to rooftop or small C&I systems. Every example and framing in current reporting points to utility-scale ground-mount, but this isn't explicitly confirmed either way for smaller systems, don't assume exemption or inclusion.
• Confusing the capacity requirement with the duration requirement. The 10% capacity figure doesn't change between 2027 and 2029, only the required storage duration doubles from 2 hours to 4.
• Treating 15% and 10% as fixed forever. CEA explicitly reserved the right to modify these percentages after finalization.
• Conflating this with the separate 2025 CEA amendment. There's an entirely different "2nd Amendment Regulations, 2025" covering structural testing and cybersecurity standards, don't mix the two documents up when researching or citing this topic.

Where Reslink Fits In This Conversation

A client asking whether their 2027-commissioning project needs to budget for grid-forming inverters and co-located storage deserves a real answer, not a shrug, even while the rule is still in draft. Reslink's proposal workflow lets you model both scenarios, with and without the mandate applying, side by side, so a client sees the actual cost range rather than a single number that might be wrong either way. That's a more honest conversation than waiting until the regulation finalizes to have it at all.

Frequently Asked Questions

Q1. When will these regulations actually be finalized?

No confirmed date exists yet. CEA states the draft will be considered after the October 4, 2026 comment period closes, but finalization timing itself isn't specified in the draft or in any source checked here.

Q2. Does the storage requirement apply to floating solar projects?

Not confirmed either way in the sources checked. The storage mandate is specifically framed around "ground-mounted solar and onshore wind," and floating solar wasn't explicitly addressed in current reporting on this specific amendment.

Q3. What happens to projects that already began construction before this rule takes effect?

Not addressed in current reporting. The July 1, 2027 date is described as a commissioning-date trigger, but whether there's a grandfathering provision for projects already under construction isn't confirmed, worth checking directly with CEA if this affects a live project.

Q4. Is 15% grid-forming inverters a lot, technically speaking?

It's a genuinely new requirement category for Indian utility-scale renewables, grid-forming inverters actively help stabilize grid voltage and frequency rather than just following it. The commercial availability and cost premium of grid-forming-capable inverters at scale in India wasn't addressed in the sources checked for this piece.

Q5. Where can I read the actual draft regulation text?

CEA's website, cea.nic.in, hosts draft notifications for public comment. This piece is built from secondary reporting citing the draft's specific provisions, not a direct read of the primary document, worth checking CEA's site directly for the full text before making a final compliance decision.

Sources

• SolarQuarter: solarquarter.com, September 3, 2026, confirms Regulation 106B(20), the 15% grid-forming inverter requirement, and the comment submission process
• pv magazine (PV Tech): pv-tech.org, confirms the draft's issuance under Section 177 of the Electricity Act, 2003, and that CEA retains discretion to modify the percentages
• Saur Energy: saurenergy.com, confirms the 2-hour and 4-hour storage duration phases and the "ground-mounted solar and onshore wind" scope framing
• Power Line Magazine: powerline.net.in, confirms the July 2029 to June 2031 escalation window and the 10% capacity requirement staying constant
• Business Standard: business-standard.com, confirms the 8,133 GWh Q1 curtailment figure and the renewable energy ministry official's statement on the rationale
• T&D India: tndindia.com, confirms the 100 MW worked example figures for both storage phases