How Many kW of Solar Do You Need to Run a 1.5-Ton AC?

To run one 1.5-ton inverter AC for 6–8 hours a day alongside normal household load, you need a 3 kW rooftop solar system; for two such ACs, 5 kW. The AC draws about 1–1.5 units an hour, a 3 kW system produces 12–13 units a day in Madhya Pradesh and Chhattisgarh, and with net metering the surplus from the day covers the evening.

What a 1.5-ton AC actually consumes

The nameplate on a 1.5-ton (5,000 W cooling) air conditioner is misleading for sizing. What matters is electrical input, which depends on the technology and the thermostat:

An inverter AC runs its compressor at reduced speed once the room reaches temperature, so its average draw is far below its peak. A fixed-speed AC cycles on and off at full power. In Gwalior, Shivpuri or Bilaspur summers, with 42–45 °C afternoons, expect the upper end of each range.

The sizing arithmetic

Add the AC to the rest of the home. A typical family uses 5–7 units a day without air-conditioning — fans, lights, refrigerator, TV, washing machine, water pump. Add one 5-star inverter AC for 8 hours and the total is about 14–17 units on a summer day. A 3 kW system produces 15–16 units a day in April–May, when the AC runs most, and 12–13 units averaged across the year.

• One 1.5-ton inverter AC + home load: 3 kW. The summer surplus is small, so the system is sized just right rather than oversized.
• Two 1.5-ton ACs, or one AC running 12+ hours: 5 kW, which produces 20–22 units a day in summer and 600–650 units a month on average.
• A non-inverter AC: add roughly 1 kW to either figure — or replace the AC; a new 5-star inverter unit often costs less than the extra solar capacity it would need.
• Three or more ACs, or a 2-ton unit: 7–10 kW, usually a three-phase connection; confirm the sanctioned load with MPMKVVCL, MPPKVVCL or CSPDCL first.

"But the AC runs at night — how does solar help?"

This is the most common question, and the answer is net metering. An on-grid system does not store electricity; during the day it feeds your load and exports the surplus through a bi-directional meter, and at night you draw from the grid as usual. The DISCOM subtracts exported units from imported units on the monthly bill. So a 3 kW system exporting 10 units at noon and a household importing 10 units for the AC at midnight nets to zero. No battery is needed for savings. A battery is needed only if you want the AC to run during a power cut — that is a hybrid system, which costs 40–60 per cent more and makes sense for clinics, resorts and homes in areas with long outages, not for ordinary bill savings.

What it costs, with subsidy

A home paying ₹3,000 a month in summer and ₹1,500 in winter — about ₹27,000 a year — recovers the ₹1,22,000 net cost of a 3 kW system in roughly four and a half years. Financed through HDFC Bank, SBI, PNB or Bank of Baroda over seven years, the EMI of about ₹2,000 is lower than the summer bill it replaces.

Four things that change the answer

• Roof shade — a water tank shadow across one panel at 2 pm, when the AC is working hardest, can cut a string's output by a fifth. The site survey maps it.
• Insulation and set temperature — every degree below 24 °C adds about 6 per cent to AC consumption. Set 26 °C with a fan and the same 3 kW covers more hours.
• Sanctioned load — a 3 kW system needs a sanctioned load of at least 3 kW on your DISCOM connection; many older homes are on 1–2 kW and need an upgrade first, which Sunvera files along with the net-metering application.
• Future ACs — if a second AC is planned within two years, size for it now; adding panels later means a second inverter or a replacement.

Get the number for your home

Send Sunvera Energy your last 12 electricity bills on WhatsApp at +91 77103 07937. Annual units divided by 1,500 is the kW you need in Madhya Pradesh or Chhattisgarh; the free site survey then confirms the roof, the shade and the sanctioned load, and the written quotation shows the exact system, price, subsidy and expected monthly generation.

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