India Wants Storage Bolted to Every New Solar Plant

Written 10 September 2026, on a draft amendment the Central Electricity Authority notified on 3 September 2026 and which was reported on 8 September. It is a draft out for comment, not a rule in force.

The Central Electricity Authority has proposed that new ground-mounted solar and onshore wind plants be built with storage attached. The mechanism is a draft second amendment to its Technical Standards for Construction of Electric Plants and Electric Lines regulations, and the requirement is stated as a proportion of the generating plant rather than as a target anybody can defer.

For projects commissioned from 1 July 2027, the draft requires co-located storage with a minimum duration of two hours and a power capacity of at least 10 per cent of the plant’s installed capacity. For projects commissioned between 1 July 2029 and 30 June 2031, the same 10 per cent applies but the minimum duration rises to four hours.

• •Co-located storage. At least 10 per cent of installed capacity, two hours minimum, for plants commissioned on or after 1 July 2027. A 100 MW solar plant would need at least 10 MW of storage able to run for two hours.
• •Longer duration later. Four hours minimum for plants commissioned in the 1 July 2029 to 30 June 2031 window, same 10 per cent of capacity.
• •Grid-forming inverters. At least 15 per cent of inverters on plants commissioned after 1 July 2027 must have grid-forming controls — able to establish voltage and frequency rather than merely follow a grid that other plant is holding up.

India has added variable generation faster than it has added the things that make variable generation manageable. Solar produces at midday and demand peaks after sunset, and as the solar fleet grows that mismatch turns into curtailment at one end of the day and expensive generation at the other.

There are two ways to fix it. Procure storage separately, through tenders, and hope the quantity arrives where the grid needs it. Or attach a minimum quantity to every new renewable plant, so the fleet arrives pre-firmed. The draft takes the second route in addition to the first, not instead of it.

The grid-forming requirement is the less-discussed half and arguably the more consequential. A grid running on inverters that all need something else to synchronise to has a stability problem that no amount of stored energy solves. Requiring a share of inverters to hold the reference themselves is how that gets addressed.

• •Storage becomes a line in the capital cost of every new solar and wind project, not an optional add-on justified by its own business case
• •Land requirements rise, and the layout has to accommodate containers, separation distances and fire access from the outset
• •The connection application changes, because the plant now exports a different profile than an unfirmed one
• •Inverter procurement specifications change for the grid-forming share, which is not merely a firmware option on every product on the market
• •Project economics shift toward developers who can finance and integrate storage, and away from those set up to build solar alone

Two things are worth separating. That India will require storage alongside new renewables is close to settled — the CEA has now put it in writing twice, in different instruments, and the physics behind it does not negotiate.

Exactly what the final numbers are, and whether 1 July 2027 survives contact with an industry that has to procure cells against it, is genuinely open. If you are developing a plant that commissions after mid-2027, the prudent reading is that some co-located storage obligation will apply, and that reserving space and connection headroom for it costs far less now than retrofitting it later.