Solar panels vs inverter battery: which should an Indian home buy first?
Grid-tied solar vanishes during a power cut by law — that surprise trips up most buyers. How each option works, what they cost, and the sensible order to buy them in.
Quick answer
- Grid-tied rooftop solar shut down during a power cut (anti-islanding) — it does not provide backup on its own.
- A battery inverter keeps the lights on during cuts but does nothing to your bill between cuts.
- They solve different problems: bill reduction (solar) vs outage resilience (battery) — hybrid systems do both at a higher cost.
The surprise most buyers hit: grid-tied solar does not work in a power cut
A standard grid-tied rooftop solar system is required to shut down when the grid fails — anti-islanding protection stops your panels from energising a “dead” line and endangering line workers. So the most common disappointment in Indian solar: the day of the big outage, the solar home is dark too.
Solar’s benefit is financial: it offsets your daytime consumption and, under net metering, exports surplus to the grid as credits. It is a bill-reduction machine, not a backup device.
What a battery inverter does and does not do
An inverter with batteries keeps essential loads alive through cuts — fans, lights, TV, router, sometimes a fridge — and recharges from the grid when supply returns. It does not reduce your consumption; every unit it delivers during a cut was bought from the grid earlier (with conversion losses).
That is the complementary pairing: solar attacks your bill every sunny day; the battery attacks outages. If outages are your actual pain point, the inverter comes first. If your bill is the pain point, solar first.
Hybrid systems: both at once, at a price
A hybrid inverter connects panels, battery and grid: it powers the house from solar, charges the battery from surplus, exports the rest, and keeps essential circuits alive during cuts. Costs in 2026 for a typical 3–5 kW hybrid setup with lithium storage run roughly ₹3–6 lakh before subsidy; a grid-tied 3 kW system without storage is closer to ₹1.5–2 lakh after PM Surya Ghar subsidies.
Subsidies under the PM Surya Ghar Muft Bijli Yojana apply to grid-connected rooftop systems; confirm current central and state subsidy amounts on the national portal before quoting, as they change.
A sensible order for most homes
1) Cut consumption first — every rupee spent on efficiency (LEDs, 5-star appliances, AC discipline) is the cheapest “unit” you will ever buy. 2) Buy a properly sized inverter + battery for outage resilience — this solves the daily pain. 3) Add rooftop solar for the bill — grid-tied, or hybrid if you want solar to also feed your battery. 4) Size the battery from real outages: long daily cuts justify lithium; rare evening dips make lead-acid the value pick.
Do it in that order and each purchase stands on its own; do it backwards (solar first “because it’s trendy”) and you may own a bill-reducer that goes dark exactly when you need it most.
Frequently asked questions
Can I add a battery to my existing grid-tied solar system?
Usually yes, via an AC-coupled battery system or by replacing the grid-tied inverter with a hybrid one. Both add cost; get a quote comparing retrofit versus a new hybrid install before deciding.
How much does a 3 kW solar system save per month?
A well-placed 3 kW system generates roughly 300–360 units a month depending on city and season. At slab tariffs of ₹6–10 per unit, that can offset ₹2,000–3,500 monthly — your actual bill structure and net-metering policy decide the final number.
Does solar work during cloudy or monsoon days?
Output drops to roughly 20–50% of sunny-day generation under heavy cloud. Net metering smooths this annually — you bank summer surpluses — but a battery, not solar, is what carries you through an evening cut.