Can You Run an AC on Solar or an Inverter? What It Really Takes

This is one of the most common questions we get at our Ashok Vihar shop, especially from April onwards: "My inverter runs the fans and lights fine — can I just add the AC to it?" The honest answer is yes, an AC can run on an inverter, and it can run on solar too. But an AC is a completely different class of load from fans and tube lights, and the system it needs is bigger, heavier and more expensive than most people expect. This guide walks a Delhi homeowner through what it actually takes, so you can decide with eyes open instead of being disappointed after you buy.

Why an AC is so much harder than fans and lights

A ceiling fan draws 40–80 watts. A 1.5-ton air conditioner draws roughly 1,500–2,000 watts while running — that alone is the equivalent of 20 to 30 fans. But the running figure isn't even the real problem. The bigger challenge is the startup surge: when a conventional (fixed-speed) AC compressor kicks in, it can briefly pull two to three times its running current for a fraction of a second. An ordinary home inverter sized for lights and fans simply trips or shuts down at that moment. This is the single most important thing to understand — sizing for an AC is mostly about surviving that surge, not just the steady load.

• Ceiling fan: 40–80 W
• LED TV + Wi-Fi: roughly 100–150 W together
• 1-ton AC: about 1,000–1,200 W running (3-star), higher at startup
• 1.5-ton AC: about 1,500–2,000 W running, with a heavy momentary startup surge
• 2-ton AC: about 2,000–2,500 W running, even larger surge

Running an AC on an inverter: what it really takes

To run a single AC on inverter backup during a power cut, you need two things sized correctly together: a high-capacity inverter and a substantial battery bank. As a practical starting point in Delhi homes, a single 1–1.5 ton AC needs an inverter of about 2.5–3.5 kVA, running off a 24V–48V battery bank (typically two to four large tubular batteries in series). A 1.5 kVA unit is the bare minimum people ask about, but on its own it leaves no headroom for the surge plus your other loads, which is why we usually point customers towards the higher-capacity Jumbo Home UPS range for this. The exact size depends on the AC tonnage, its star rating, and whether it's an inverter-type compressor.

Notice the last column. This is the part people find hardest to accept: even with a big inverter and a heavy battery bank, the backup on an AC is short — often just an hour or two, not a whole evening. An AC drains a battery roughly 20–30 times faster than your fans and lights do. Extending that to several hours means a much larger (and much more expensive) battery bank, plus a real charging burden the next day. An inverter is genuinely good for riding through Delhi's typical short, frequent cuts with your AC still on. It is not an economical way to air-condition a room for a four-hour outage. A small but important tip: an inverter-type (variable-speed) AC has a far gentler startup and is much kinder to a battery system than an old fixed-speed unit, so it's the better choice if you're planning backup.

Running an AC on solar: offsetting your bill vs running through a cut

"Can solar run my AC?" actually splits into two very different questions, and mixing them up is where most confusion comes from. Question one: can solar offset the electricity cost of running my AC? Question two: can solar keep my AC running when the grid is down? These need different systems, and the second one costs more.

• Offsetting the bill (on-grid solar): A 1.5-ton AC running about 6–8 hours a day uses roughly 8–12 units. As a rule of thumb, about 1 kW of rooftop solar in Delhi generates around 4–4.5 units on a good day, so a 3–5 kW system can substantially offset — even fully cover — daytime AC use over the month through net metering. But a plain on-grid system shuts off during a power cut. It lowers your bill; it does not give you backup.
• Running through a cut (hybrid / solar + battery): To keep the AC actually running when the grid fails, you need a hybrid system — solar panels plus a solar PCU (inverter) plus a battery bank. This is the setup that both saves on your bill and carries you through outages, and it is the most expensive of the three options.

For a Delhi home that wants AC comfort during cuts and lower bills, a hybrid system in the 3–5 kW range with a battery bank is the realistic answer. The plain on-grid route is excellent value if your goal is purely to cut the monthly bill and your cuts are short — and with rooftop solar you also get the subsidies, which a battery inverter alone does not qualify for.

Being honest about the cost — and the subsidy

There's no point pretending an AC-capable system is cheap, so here are real ranges. A high-capacity inverter and battery bank able to run a 1.5-ton AC typically runs into several tens of thousands of rupees once you include the larger batteries — and remember those batteries are a recurring cost every few years. On the solar side, on-grid residential rooftop runs about ₹55,000–₹85,000 per kW installed (roughly ₹1.5–1.9 lakh for the popular 3 kW size; ₹3–3.5 lakh for 5 kW). A hybrid system with batteries costs more than a plain on-grid system of the same size, because of the battery bank and hybrid PCU.

The good news is that rooftop solar is heavily subsidised, which an inverter-only setup is not. Under PM Surya Ghar Muft Bijli Yojana, the central subsidy is ₹30,000 per kW for the first 2 kW and ₹18,000 for the 3rd kW, capped at ₹78,000 for systems of 3 kW and above, paid directly to your bank account. On top of that, the Delhi Solar Policy 2024 adds a state subsidy of ₹2,000 per kW (up to ₹10,000), credited via your first electricity bill, plus a Generation Based Incentive of ₹3 per unit for 1–3 kW domestic systems — roughly ₹700–₹900 a month for a typical home. That ₹78,000 central subsidy alone covers roughly 45–50% of a typical 3 kW system. (Figures are as of 2025–26; please confirm current rates on pmsuryaghar.gov.in and solar.delhi.gov.in before you commit.)

So which should you choose?

• You mainly face short, frequent cuts and want the AC to stay on through them: a high-capacity inverter (about 2.5–3.5 kVA for one AC) with a substantial battery bank. Expect short backup — an hour or two — not all night.
• Your bills are high from heavy AC use and your cuts are short: on-grid rooftop solar, sized around 3–5 kW, to slash the monthly bill and claim the subsidies. No backup during a cut, but the best economics.
• You want both lower bills and AC comfort during outages: a hybrid solar system (solar + PCU + battery) in the 3–5 kW range. Highest upfront cost, but it does both jobs.
• Practical point on roof space: solar needs about 80–100 sq ft per kW, so a 3 kW system wants roughly 250–300 sq ft of shadow-free roof — worth checking before you plan.

There's no single right answer here — it depends on your AC tonnage, how long your cuts actually last, your roof, and your budget. That's exactly the kind of sizing we do every day for homes across Delhi, Gurgaon, Noida, Ghaziabad and Faridabad. Tell us the AC's tonnage and star rating and roughly how long your cuts run, and we'll work out an honest system size and a realistic cost — including whether solar, an inverter, or a hybrid genuinely makes sense for your home, and we'll install and service it locally afterwards.