Does Rooftop Solar Work During a Power Cut? Myths vs Facts

Load-shedding is still a reality in many parts of India, and one of the most common reasons families and shop owners give for installing rooftop solar is: "At least we will have power when the light goes." Then the first power cut comes, the inverter display goes off, and the house is dark even at noon. Is the system faulty? Usually not. In this post the SolarConnect India team busts the most common power-cut myths so you buy the right system the first time.

Quick Answer: Does Solar Work During a Power Cut?

A standard on-grid (grid-tied) solar system does NOT supply power during a grid power cut, even on a sunny day. It switches off automatically for safety. To get backup you need a hybrid system with a battery or an off-grid system. Which one is right depends on how long and how often your power cuts are, and which loads you want to run.

Myth 1: "If the sun is shining, my on-grid solar will run my house during a power cut"

Fact: On-grid inverters have built-in anti-islanding protection. When grid supply fails, the inverter must stop feeding power within seconds. This is required by grid-connectivity safety standards so that electricity-board linemen repairing the line are not hit by power coming back from your roof. So even at 12 noon in full sun, a pure on-grid system shuts down when the grid goes down and restarts automatically once supply returns.

Myth 2: "My on-grid system is faulty because it stops when the grid fails"

Fact: That is correct and safe behaviour, not a fault. An inverter that kept running during a grid failure would be unsafe and non-compliant. If your system stops during power cuts and restarts after the grid returns, it is working exactly as designed. Real faults look different: low generation on normal sunny days, error codes, or no restart after supply comes back. For those, see our guide on why solar panels produce less electricity.

Myth 3: "On-grid solar is useless in areas with power cuts"

Fact: On-grid solar still cuts your electricity bill on every day the grid is available, which is most hours of the year in most cities. With net metering, extra daytime units are exported and adjusted in your bill. On-grid is also the lowest-cost option and is the most common system type installed under PM Surya Ghar. The question is not "useful or useless" but "do I also need backup?" If cuts are short and rare, an on-grid system plus your existing small inverter-battery for lights and fans is often enough.

Myth 4: "Any solar system with a battery gives full-house backup"

Fact: Backup depends on battery size and inverter rating. A typical home battery can run lights, fans, Wi-Fi, TV and a fridge for a few hours, but heavy loads like a 1.5-ton AC, geyser, induction cooktop or water pump can drain it very fast or exceed the inverter capacity. Good design separates essential loads (on backup) from heavy loads (grid/solar only). Our battery sizing and hybrid inverter guide explains how to calculate the battery you actually need.

Myth 5: "I have to choose between saving on bills and getting backup"

Fact: A hybrid system does both. It works like an on-grid system when the grid is available (bill savings and net metering where permitted) and switches to battery-plus-solar during a power cut, keeping essential loads running. The trade-off is cost: hybrid inverters and batteries add to the project price, and batteries need replacement after their rated life. If you already have on-grid solar, you can often upgrade later, see can you add a battery to on-grid solar later.

Myth 6: "Hybrid or battery systems don't get PM Surya Ghar subsidy"

Fact: PM Surya Ghar: Muft Bijli Yojana supports grid-connected rooftop solar for homes. The subsidy is calculated on the solar capacity: ₹30,000 per kW up to 2 kW, plus ₹18,000 for the 3rd kW, with a maximum of ₹78,000 for 3 kW and above. The battery itself is not subsidised, so you pay its full cost. Eligibility also depends on using approved (DCR) panels, a registered vendor and the DISCOM process, so confirm details with your vendor before you apply. Read our PM Surya Ghar 1 kW to 3 kW subsidy guide for the full process.

On-Grid vs Hybrid vs Off-Grid: Which Works in a Power Cut?

For a deeper comparison, read on-grid vs off-grid vs hybrid solar.

How to Decide in 3 Steps

1. Check your power-cut pattern: how many hours per day or week, and at what time (day or night).
2. List essential loads: lights, fans, router, fridge, computer, a small pump? Add up their watts and hours.
3. Match the system: rare cuts → on-grid; regular cuts → hybrid with a battery sized for essential loads; no reliable grid → off-grid.

For businesses, factories and commercial buildings, the same logic applies at a larger scale, often with DG-sync or larger storage. The SolarConnect India team designs commercial systems through our pan-India EPC and dealer network.

FAQ: Solar and Power Cuts

Why does my on-grid solar inverter switch off during a power cut?

Because of anti-islanding protection. It stops feeding power when the grid fails so that line workers stay safe, and it restarts automatically when supply returns.

Can I run my home on on-grid solar without a battery during a power cut?

No. A standard on-grid inverter needs the grid to be present to operate. For backup you need a hybrid inverter with a battery or an off-grid system.

Can I add a battery to my existing on-grid system?

Often yes, either by replacing the inverter with a hybrid model or adding a compatible battery solution. A site check is needed to confirm compatibility.

Is a battery covered under PM Surya Ghar subsidy?

No. The subsidy is based on rooftop solar capacity (₹30,000/kW up to 2 kW, ₹18,000 for the 3rd kW, maximum ₹78,000). Battery cost is paid by the customer.

Can a hybrid solar system run an AC during a power cut?

Only if the inverter and battery are sized for it. Most home backups are designed for essential loads; running an AC on battery needs a much larger battery and inverter.

Want to bust more solar myths? Visit our Solar Myths vs Facts page.

Get the Right System for Your Power-Cut Needs

Not sure whether you need on-grid, hybrid or off-grid? The SolarConnect India team will check your bill, load and power-cut pattern and suggest the right size with partner-brand panels, anywhere in India, for homes and large commercial projects.

📱 WhatsApp / Team: +91 92823 67700  |  ☎️ Office: 033 3183 5203