Solar panels for AC: how much solar do you need to run a 1.5-ton air conditioner?

In Telangana and Andhra Pradesh, the air conditioner is often the single biggest reason a summer electricity bill jumps. So it is natural to ask: can solar panels run my AC? The answer is yes, and doing it well is less about wiring the AC to the panels and more about sizing your whole solar system so that it covers the extra units your AC uses.

This guide explains how much power an AC uses, how to work out how much solar covers it, why an on-grid system is usually the best way to do it, and why running an AC on batteries during a power cut is rarely worth it.

The short answer

You do not usually connect an AC directly to solar panels. Instead, a grid-connected rooftop system produces units during the day, your home uses them (including for the AC), and any surplus is exported and credited through net metering. Size the system so that, over a month, it produces roughly the extra units your AC adds to your bill.

As a rough guide, a 1.5-ton inverter AC running several hours a day for the summer months typically needs somewhere in the region of 1.5 to 3 kW of additional solar, depending on how many hours it runs, its star rating and how hot your home gets. The rest of this article shows how to work out your own figure.

How much electricity does an AC use?

An AC's consumption depends on its capacity (tons), type (inverter or fixed-speed), star rating, the room size, insulation, and how hot it is outside.

As a broad, rough guide, a 1.5-ton AC draws somewhere around 1 to 2 kW while its compressor is running hard. An inverter AC varies its compressor speed, so once the room is cool it uses noticeably less than a fixed-speed (non-inverter) AC, which switches on and off at full power. Higher star ratings use less.

The best source is your own AC. Look at:

• the energy label, which states the annual energy consumption under test conditions;
• the rated power input on the nameplate;
• your summer vs winter electricity bills: the difference is largely the AC (and fans and coolers).

The bill difference is the most practical number of all, because it reflects how you actually use the AC.

Working out how much solar you need for your AC

Method 1: from your bills (most practical)

1. Find your average monthly units in the summer months when the AC runs.
2. Find your average monthly units in the cooler months when it does not.
3. The difference is roughly what the AC (and summer cooling) adds.
4. Divide that difference by about 130, the average monthly units from 1 kW of solar in our region.

Example: your bill is 300 units a month in winter and 550 units in summer. The AC adds about 250 units a month in summer. 250 ÷ 130 ≈ 1.9, so about 2 kW of additional solar covers it on an average month.

Method 2: from usage hours

1. Estimate how many units the AC uses per hour. For a 1.5-ton inverter AC in a hot room, a rough figure of around 1 to 1.5 units per hour is a reasonable starting point. Your energy label gives a better figure.
2. Multiply by hours of use per day.
3. Divide the daily units by about 4.3, the average daily units per kW of solar in our region.

Example: 8 hours a day × about 1.2 units per hour ≈ 10 units a day. 10 ÷ 4.3 ≈ 2.3, so about 2.3 kW of solar.

Both methods give an estimate. A site visit and a look at your actual bills firm it up.

Why on-grid solar is usually the best way to cover your AC

A common misunderstanding is that solar panels power the AC directly, so the AC only runs when the sun shines. With an on-grid system, that is not how it works, and that is good news.

During the day: your solar system produces power. Your AC, fans, fridge and everything else use it directly. Anything left over is exported to the grid.

In the evening and at night: you draw power from the grid as usual, including for the AC.

On your bill: net metering credits the units you exported against the units you drew. So daytime surplus helps pay for night-time AC use.

This is why sizing the system to your monthly units works. You do not need batteries, and the grid acts like a bank for your surplus. Our article on what "prosumer" means explains how the credit appears on your bill.

One practical tip: run the AC during sunny hours where you can. Pre-cooling the house in the afternoon, when your panels are producing strongly, uses your own solar directly.

Why running an AC on batteries is expensive

People sometimes ask for a system that runs the AC during power cuts. It is possible with a hybrid or off-grid system, but it is rarely worth it for a home:

• ACs draw a lot of power. A battery large enough to run an AC for several hours is far bigger and more expensive than one that runs lights, fans and a fridge.
• Starting current. Fixed-speed ACs draw a surge when the compressor starts. The inverter and battery must handle that surge.
• Battery wear. Running a heavy load drains batteries deeply and shortens their life, especially lead-acid.

For most homes, it makes far more sense to back up essentials (lights, fans, Wi-Fi, fridge) during outages and leave the AC on the normal grid circuit. Our solar battery guide and battery backup calculator help you plan backup for the loads that matter.

Do you need a special "solar AC"?

You will see DC or "solar" air conditioners marketed for direct solar use. They are a niche product, useful mainly for off-grid sites. For a home with a grid connection, a good inverter AC combined with an on-grid solar system is simpler, cheaper and easier to service. If you are buying a new AC anyway, choose an inverter model with a high star rating; it reduces how much solar you need.

Other ways to reduce how much solar your AC needs

Every unit you save is a unit you do not need to generate:

• Set the AC to 24 to 26°C rather than very low temperatures.
• Use ceiling fans with the AC to spread cool air.
• Shade the windows that get afternoon sun.
• Keep doors and windows closed while the AC runs.
• Clean the AC filters regularly.
• Insulate or shade the roof. On top floors, a hot roof makes the AC work much harder. A raised solar structure also shades part of the roof.
• Service the AC so it runs efficiently.

Sizing your whole system, not just the AC

Your AC is one part of your home's use. The right approach is to size the solar system to your total annual consumption, with the AC's summer load included:

1. Take your total units for the last 12 months.
2. Divide by about 1,550 to 1,600, the annual units per kW in our region.
3. That is roughly the kW that covers your full year.

Example: a home using 5,400 units a year (450 a month on average) needs about 3.4 to 3.5 kW. In practice that is a 3.5 kW or 4 kW system, depending on the roof and the sanctioned load.

If you plan to add an AC soon, include it now. Adding panels later costs more per kW than installing the right size once.

Sanctioned load and DISCOM rules

Adding solar, and adding an AC, both interact with your sanctioned load (the maximum load your connection is approved for). DISCOM rules link how much solar you can connect to your sanctioned load and connection type. If you are adding a big AC and a solar system together, check whether your sanctioned load needs to increase. We check this during the site visit and handle the DISCOM coordination for the net meter as part of the installation.

What it costs

The extra solar to cover an AC follows normal system pricing. For reference, Origian's gross prices (before any subsidy) are:

• 2 kW: ₹1,70,000 to ₹1,90,000
• 3 kW: ₹2,30,000 to ₹2,60,000
• 5 kW: ₹3,50,000 to ₹3,90,000

If you are adding AC coverage to an existing need, the right move is usually a slightly bigger system rather than a separate one. See our full solar system prices and our home solar cost guide.

A note on the subsidy: the PM Surya Ghar subsidy is paid only for systems installed by a vendor registered with your DISCOM. Origian Power is not a registered PM Surya Ghar vendor, so a system we install does not qualify for it. We quote full prices.

A worked example from a typical Hyderabad home

Consider a family in Hyderabad with:

• 320 units a month in winter;
• 600 units a month in summer, with two 1.5-ton inverter ACs;
• about 5,600 units over the year.

Sizing:

• 5,600 ÷ 1,550 to 1,600 ≈ 3.5 to 3.6 kW to cover the full year.
• A 4 kW system gives a little headroom for growth.

What it means:

• In summer, the system covers a large part of the higher bill, with net metering crediting daytime surplus against evening AC use.
• In winter, it produces more than the home uses, building credit.
• No batteries are needed unless outages are a problem.

This is an illustration. Your figures depend on your bills, roof and shading.

How Origian sizes solar around your AC

During the free site visit, we look at your bills across seasons, your AC use and any plans to add cooling, then size the system to your annual consumption. We check your sanctioned load and roof space, design the layout to avoid shade, and quote the full price with the exact equipment. Every system includes galvanised wind-rated structures, separate lightning-arrestor earthing, surge protection on both DC and AC sides, and maintenance every three months.

To find the right size for your home, book a free site survey, or try our solar vs bill calculator.

Inverter AC vs non-inverter AC with solar

If you are choosing an AC to pair with solar, the inverter AC is almost always the better choice:

• Lower average consumption. An inverter AC slows its compressor once the room is cool instead of switching on and off at full power.
• Gentler start-up. It ramps up gradually, avoiding the large starting surge of a fixed-speed compressor. This matters if you ever plan battery backup.
• More stable room temperature, which usually means more comfort at a higher thermostat setting.

If you have older non-inverter ACs, replacing the one you use most with an efficient inverter model can reduce how much solar you need.

Multiple ACs and summer peaks

Many Hyderabad homes run two or three ACs in summer, often at the same time in the evening. Two points to plan for:

1. Monthly units. Size the solar system from your yearly consumption, including the summer AC months, so net metering credits from sunny periods help cover summer evenings.
2. Sanctioned load. Running several ACs at once can push your load close to your sanctioned limit. If you are adding ACs and solar together, check whether your sanctioned load needs to increase. We check this during the site visit.

Rooftop heat and your AC

On top floors, a hot concrete roof radiates heat into the rooms below and makes the AC work much harder. A raised solar structure shades part of the roof, which can help a little. Light-coloured roof coatings and good roof insulation help more. Every degree you keep out of the room reduces the units your AC needs, and the solar you need to cover them.

Planning for a future AC

If you do not have an AC yet but expect to add one within a year or two, size your solar system with it in mind. Adding panels later is possible, but it costs more per kW than installing the right size once, and it means a second round of DISCOM paperwork. Tell your installer about planned appliances, including ACs, geysers and electric vehicles, during the site visit.

Star ratings, thermostat settings and your solar size

The AC you choose, and how you use it, changes how much solar you need.

• Star rating: a higher-rated AC uses fewer units for the same cooling. If you are replacing an old AC anyway, a more efficient model can let a smaller solar system cover it.
• Thermostat setting: each degree cooler on the thermostat makes the compressor work harder. Setting the AC a little warmer, with a ceiling fan running, often feels just as comfortable and uses noticeably less power.
• Room insulation: closing curtains on west-facing windows, sealing gaps around doors and shading the roof all reduce the cooling load.
• Servicing: clean filters and a well-maintained outdoor unit keep the AC efficient. A neglected AC can use much more power for the same cooling.

These steps cost little, and every unit they save is a unit your solar system does not need to produce.

Day use vs night use

Solar produces power during the day, but many households run their ACs mostly at night. With net metering this is fine: the surplus your panels export during the day is credited against the units you import at night, within the billing rules of your DISCOM. You do not need batteries for the savings to work. Our guide to being a prosumer with net metering explains how the credit works.

If you are at home during the day, running the AC in the afternoon, when the panels are producing most, uses your solar power directly. That is the most efficient use of all.

Frequently asked questions

How many solar panels are needed to run a 1.5 ton AC? A 1.5-ton AC typically needs about 2 to 3 kW of rooftop solar to cover its energy over a month, depending on star rating, thermostat setting and hours of use. With net metering, the panels don't need to power the AC directly; daytime surplus credits offset night-time AC use.

Can a 3 kW solar system run an AC? Yes, in energy terms. A 3 kW rooftop solar system produces about 400 units a month in our region, enough to cover a typical 1.5-ton AC's use plus some household load, depending on hours. Under net metering the AC can run at night too, using credits from daytime surplus.

Can I run 2 ACs on a 5 kW solar system? A 5 kW rooftop solar system produces about 650 units a month in our region, which can cover two efficient ACs used a few hours a day along with normal household loads. Heavier use needs more capacity. On-grid with net metering is the practical setup; running two ACs on batteries is costly.

How many ACs can a 3 kW solar system run? In energy terms, a 3 kW rooftop solar system's roughly 400 units a month can cover one 1.5-ton AC used several hours a day plus other household loads. Two ACs used heavily would need a larger system, typically 5 kW or more. Size from your summer bills for an accurate answer.

Can an AC run directly on solar panels without batteries? Yes, with an on-grid solar system. In daylight the AC uses solar power first, topped up from the grid when needed, and any surplus is exported through net metering. An on-grid system shuts down in a power cut, though, so the AC stops then unless you have a hybrid system with batteries.

Do I need a special solar AC? No. A normal inverter AC works with a rooftop solar system; the solar system supplies your home's wiring, not the AC specifically. Dedicated "solar ACs" exist, but for most homes an efficient, high-star-rated inverter AC plus an on-grid solar system is the simpler and cheaper route.

How much does solar for an AC cost in India? Covering a typical 1.5-ton AC usually needs about 2 to 3 kW of rooftop solar. Origian's gross prices are ₹1,70,000 to ₹1,90,000 for 2 kW and ₹2,30,000 to ₹2,60,000 for 3 kW, before any subsidy. The right size depends on your whole household's consumption, not the AC alone.