The question every C&I solar owner eventually faces
Your rooftop solar plant makes the most power at midday — often more than the factory or office is using at that moment. That surplus has to go somewhere. For years the default answer was simple: push it onto the grid and let net metering credit you for it. But the value of that export is falling, and for many commercial and industrial (C&I) sites the smarter move is now to store the surplus in a battery and use it yourself later.
Which choice wins is not a matter of opinion. It comes down to two numbers: what your DISCOM pays you for an exported unit, and what a unit costs you to buy back. When those two numbers are close, exporting is fine. When they are far apart, storing wins.
Net metering, net billing, gross metering — the three rules that decide
The billing arrangement your DISCOM applies is the single biggest factor, so it helps to be precise about the three you might encounter.
| Arrangement | What happens to your solar | What an exported unit is worth |
|---|---|---|
| Net metering | Exports are netted against imports on one meter | Retail tariff — roughly one-for-one with what you pay |
| Net billing | Imports and exports metered separately | A lower feed-in / avoided-cost rate, often ₹3–6 per unit |
| Gross metering | All solar is exported; you buy all your load | A fixed feed-in tariff, no self-consumption at all |
Under full net metering, an exported unit is worth about the same as a unit you consume, so the grid is effectively a free battery. There is little to gain by storing that surplus — on the export question alone.
Under net billing, the arithmetic flips. Your exports are bought at a low avoided-cost rate while your imports are still charged at the full C&I retail tariff, which commonly runs ₹8–11 per unit. Every unit you export and then buy back later loses you the gap between those two prices. That gap is exactly what a battery captures.
Why the 500 kW line matters for C&I
This is not a fringe scenario for large sites. India’s Electricity (Rights of Consumers) Rules broadly allow net metering for systems up to 500 kW, subject to each state’s own regulations — and many states apply net billing or gross metering above that threshold, with some capping net metering even lower. Because C&I rooftop and ground-mount systems are often larger than 500 kW, a growing share of them simply do not qualify for full net metering in the first place. For those sites, the surplus is being exported at a discount by default, and storing it to raise self-consumption is the natural response.
The decision, in plain terms
Ask yourself three things:
- What does my DISCOM actually pay for an export? If it is close to your retail tariff (full net metering), a battery adds little on the export side. If it is a low feed-in rate (net billing or gross metering), storing wins.
- How much surplus do I export today? A site that consumes almost all its solar on-site has little to store; a site dumping half its midday generation onto the grid at a discount has a lot to recover.
- What else can the battery do? Even where exporting is fine, the same battery can shift cheap midday solar into the expensive evening peak under a Time-of-Day tariff and shave your peak demand charges — value that has nothing to do with the export rate.
That last point matters. A battery is rarely justified by the export gap alone; it is justified by stacking self-consumption, arbitrage and demand-charge savings together. A solar-plus-storage setup captures all three, which is why the payback is usually faster than any single benefit suggests.
What this means for you
If your site is above 500 kW, or your DISCOM has moved you to net billing, your exported solar is almost certainly worth less than the power you buy back in the evening — and that gap is money a battery can keep on-site. If you still enjoy full net metering, weigh storage on its arbitrage and demand-charge merits instead, not on exports. Either way, the honest answer needs your own tariff, your export volume and your load shape. A compact C&I cabinet behind the meter is often all the hardware it takes. To see how storing versus exporting plays out for your numbers, run your tariff through our savings calculator or send us your bills and export data for a modelled answer.
Policy snapshot as of July 2026. Net metering caps, feed-in and avoided-cost rates and the net-vs-gross threshold vary by state and DISCOM and change by notification — verify the current terms for your connection before financial decisions.