Running an air conditioner in summer can push your electricity bill up fast. A rooftop solar system can reduce this cost, but the right size depends on more than the AC tonnage. You must also check the AC's power use, daily running hours, other appliances, sunlight in your area and your need for battery backup.
Solar system size for a 1-ton AC and two fans
A 1-ton AC may use about 900 to 1,300 watts while running. The actual figure depends on its star rating, inverter technology, room size and thermostat setting. An inverter AC may use less power after the room reaches the set temperature.
Two regular fans may use about 150 watts together. If you also use lights, a television, a refrigerator and phone chargers, the total load can rise to 2,000 watts or more.
For a 1-ton AC, two fans and a few small appliances, a 2.5 kW to 3 kW solar system is a practical range for many homes. A 1.5 kW to 2 kW system may help reduce your bill, but it may not produce enough power to run all these devices at the same time, especially during cloudy weather.
Solar system size for a 2-ton AC and two fans
A 2-ton AC can consume around 2,000 to 3,000 watts, based on its model and operating conditions. Add two fans and other home appliances, and the load can cross 3,000 watts.
For this setup, a 4 kW to 5 kW solar system is often considered. A 4 kW system may work for daytime use with careful load management. A 5 kW system gives more room for other appliances and seasonal changes in solar output.
Do not select a system only by looking at the AC label. Check the rated input power on the AC's energy label or user manual. This number gives a better starting point than the tonnage alone.
How many solar panels will you need?
The number of panels depends on the wattage of each panel. If you use 550-watt panels, the rough count may look like this:
- 2 kW: About 4 panels
- 3 kW: About 6 panels
- 4 kW: About 8 panels
- 5 kW: About 10 panels
With 400-watt panels, you will need more panels. A 3 kW system may need around 7 to 8 panels, while a 5 kW system may need 12 to 13 panels. Your roof must have enough shadow-free space. Trees, water tanks and nearby buildings can reduce panel output.
How much solar power do two fans need?
Suppose one fan uses 75 watts. Two fans will use about 150 watts. If they run for 10 hours, their daily use will be close to 1.5 units of electricity.
A 300-watt to 500-watt system may support two fans in good sunlight. If you also want to run LED bulbs, a television, a Wi-Fi router and chargers, a 0.5 kW to 1 kW system will be more useful.
BLDC fans use less power than standard fans. Replacing old fans with BLDC models can reduce your load and may lower the solar system size you need. Your fans may not thank you, but your meter might.
On-grid, off-grid or hybrid solar?
An on-grid system works with the electricity grid. It usually costs less because it does not need batteries. During the day, solar power runs your appliances first. Extra power can go to the grid through net metering, subject to state rules. At night, you use grid electricity.
An off-grid system uses batteries and can work during a power cut. However, batteries add cost, need space and may need replacement after some years. Running an AC on batteries can also require a large battery bank.
A hybrid system combines solar, grid power and battery backup. It suits homes that want backup for selected loads. Running an AC during a long power cut can still raise the system cost.
Estimated cost of a rooftop solar system
The total cost includes panels, inverter, mounting structure, wiring, protection devices, installation and, in some cases, batteries. As a broad market estimate in India, an on-grid system may cost around:
- 2 kW: ₹1.2 lakh to ₹1.8 lakh before subsidy
- 3 kW: ₹1.7 lakh to ₹2.5 lakh before subsidy
- 5 kW: ₹2.8 lakh to ₹4 lakh before subsidy
Prices vary by panel type, inverter brand, roof structure, location and installer. Battery systems cost more. Ask for a written quote that lists every part, warranty, installation work and after-sales service.
PM Surya Ghar Muft Bijli Yojana subsidy
Under the PM Surya Ghar Muft Bijli Yojana, eligible residential consumers can apply for central financial support for rooftop solar. The commonly listed subsidy is ₹30,000 for 1 kW, ₹60,000 for 2 kW and up to ₹78,000 for 3 kW or higher systems. The final amount depends on current government rules and eligibility.
Apply through the official PM Surya Ghar portal and use an approved vendor. The process may include consumer registration, vendor selection, installation, inspection and meter approval. Check the latest subsidy rules before making payment, as rates and process details can change.
Important checks before installation
- Review the AC's rated input and starting load.
- List all appliances that may run at the same time.
- Check your roof area and daily sunlight.
- Choose an inverter that can handle the load and surge.
- Decide if you need battery backup or only bill reduction.
- Ask your electricity provider about net metering rules.
- Get a load study from a qualified solar installer.
Common questions
Can a 1-ton AC run on solar power?
Yes. A suitable solar system, inverter and electrical setup can run a 1-ton AC. For an AC with two fans and other appliances, 2.5 kW to 3 kW is a more useful starting range than a small fan-only system.
Can solar run an AC at night?
Panels do not produce power at night. An on-grid system will use grid electricity after sunset. A battery or hybrid system is needed for night-time backup.
Is a 5 kW system enough for a 2-ton AC?
It may be enough for daytime AC use along with two fans and selected appliances. The result depends on sunlight, AC efficiency, usage hours and the total household load.
