For most of the last decade, connecting a battery to the Indian grid meant applying rules written for something else. Standards existed for generators, for transmission lines, for large consumers — but a battery is none of those. It generates nothing, consumes on a schedule, and reverses direction several times a day.
That gap has now been closed. The Central Electricity Authority (CEA) — the body that writes India’s technical standards for electrical plant — has amended its construction and connectivity regulations to cover storage explicitly.
What changed
The CEA (Technical Standards for Construction of Electrical Plants and Electric Lines) Amendment Regulations, 2026 extend the connectivity framework to inverter-based resources: solar photovoltaic plants, wind farms, hybrid projects, floating solar and energy storage systems. The broader overhaul covers renewable plants, battery storage, pumped storage projects, transmission utilities and large consumers connected at 33 kV and above.
Two structural changes matter most for storage.
Storage is now defined. A battery energy storage system is described in the regulations as a stationary system connected to the electricity network using electrochemical storage — with the battery management system (BMS) and power conversion system (PCS) named as components in their own right. That sounds like housekeeping, but a definition is what makes every following requirement enforceable.
There is a dedicated safety chapter. A new Chapter XA adds safety requirements specifically for BESS installations, applying to systems connected at voltages above 650 V. Installations at 650 V and below must comply with the relevant standards instead.
The numbers to design against
A word on each:
80% depth of discharge. Depth of discharge is how much of the battery’s rated energy you can actually use. This is a capability floor — the system must be able to deliver that deeply. It does not tell you how to operate it day to day, which remains a commercial decision. We explain the term in C-rate, depth of discharge and state of charge.
95% power conversion system efficiency. The PCS is the equipment that converts between the battery’s direct current and the grid’s alternating current. Every conversion loses a little, and at grid scale a percentage point is real money — see the power conversion system explained.
70% AC-to-AC round-trip efficiency. This is the honest, whole-system number: energy out of the grid, through the battery, back into the grid. Good modern lithium iron phosphate systems sit comfortably above this, so treat 70% as a bar for excluding bad equipment rather than a specification to aim at. Our article on round-trip efficiency and degradation covers why the AC-to-AC figure is the one that matters.
Real-time monitoring, data logging, and 90 days of retention. This is the requirement most likely to be under-budgeted, because it means real storage infrastructure and a retrieval path rather than a live screen. It is also the one you will be glad of: three months of logged data is precisely what a warranty dispute or fault investigation needs.
When it bites
The amendment regulations come into effect from 1 April 2027. That is not far away for an asset with a two-year development cycle. A project being specified today will be commissioned into this regime, so the sensible course is to write these thresholds into procurement specifications now rather than retrofit compliance later.
Connectivity itself is a separate process from these construction standards — the general network access route is covered in our guide to GNA and connectivity for storage, and the safety standards landscape in BESS safety standards explained.
What this means for you
- If you are a developer or EPC contractor: put the four thresholds into your technical specification and your factory acceptance criteria, and make the supplier warrant them. AC-to-AC round-trip efficiency in particular should be a guaranteed number with a test method attached, not a datasheet claim.
- If you are a procurer or distribution company: these give you a defensible minimum specification to write into tenders, which is more useful than negotiating each requirement from scratch.
- If you are a C&I buyer below 650 V: the new safety chapter is not aimed at you, but the thresholds are still a useful shopping list. Asking a supplier for guaranteed AC-to-AC efficiency and 90 days of retrievable data is reasonable at any scale — our ADESS cabinet and container systems are specified with both.
- If you are planning a grid-connected project: grid stabilization applications sit squarely inside this framework, and our engineering team can review a specification against it — get in touch.
Regulations and technical standards change by notification and by subsequent amendment, and drafts sometimes differ from what is finally notified. Treat this as an August 2026 snapshot and verify the current text of the CEA regulations, and their applicability to your voltage level, before finalising a design.