Solar panels for an aircon: the panels, the battery and the setup
Solar can run an air conditioner. Whether it is a small job or a big one depends on one thing more than any other: when the aircon runs. In the afternoon, a few panels carry it. Overnight, the panels have stopped and a battery has to hold the whole night.
Below is the arithmetic for both, worked from two units sold here and one named battery, at the sun hours for San Fernando. It is the same working we use when we size a residential solar installation around a household that cools its bedrooms.
Start from the plate, not the horsepower
Aircons are sold by horsepower, and horsepower is what the compressor delivers. What the panels and battery have to supply is what the unit pulls from the socket, which is printed in watts on the plate on its side.
- Carrier WCARH010EE 1.0 HP window, conventional
- 930 W
- Carrier WCARH012EEV 1.5 HP window, inverter
- 625 to 1310 W
The inverter unit carries a range because it slows its compressor once the room is cool. Most of a long night it sits nearer the bottom of that range than the top, but how near depends on the room, the insulation and the setting, so the tables below show both ends.
Where these figures came from, and what other appliances draw
How many panels for a daytime aircon
Worked at 5.23 peak sun hours, the Global Solar Atlas figure for San Fernando, with a performance ratio of 0.8 for losses in wiring, heat and the inverter, and 550 W panels. The count covers the energy the unit uses over the hours shown.
| Unit, draw | 6 hours a day | 8 hours a day |
|---|---|---|
| Carrier WCARH010EE, 930 W | 3 panels | 4 panels |
| Carrier WCARH012EEV, low end, 625 W | 2 panels | 3 panels |
| Carrier WCARH012EEV, high end, 1310 W | 4 panels | 5 panels |
These are energy counts: enough panels to make, across a day, what the unit uses across those hours. They do not promise the unit runs from the panels alone at every moment. A passing cloud drops output for a minute, and on a grid-tied system the grid quietly covers the gap. That is the main reason a grid-tied array is the easy way to put an aircon on solar.
What battery a night of aircon needs
This is the part most answers skip. A night of cooling from 10 pm to 6 am is 8 hours with no sun at all. Every kilowatt-hour of it has to be stored during the day and drawn back out.
The example battery is the Deye RW-F10.2, a lithium iron phosphate unit rated at 10.2 kWh. Its datasheet gives 9.2 kWh as usable, because it is only meant to be emptied to 90 percent. The usable figure is the one to plan with, and the battery page reads the rest of the same datasheet line by line.
- Carrier WCARH010EE, 930 W
- 7.44 kWh a night One battery runs it about 9.9 hours. Refilling it takes about 4 more panels.
- Carrier WCARH012EEV, low end, 625 W
- 5.00 kWh a night One battery runs it about 14.7 hours. Refilling it takes about 3 more panels.
- Carrier WCARH012EEV, high end, 1310 W
- 10.48 kWh a night One battery runs it about 7.0 hours. Refilling it takes about 5 more panels.
Two things follow. One battery of this size covers a full night for the conventional 1.0 HP unit, but not for the inverter unit if it has to work at the top of its range all night. And the panels that refill the battery are on top of the ones that run the aircon in the day, because the same sunshine cannot do both jobs.
A battery also has to deliver the power, not just hold the energy. When a compressor starts it draws more than its running figure for a moment, and the inverter between the battery and the aircon has to be rated for that. It is one of the things we check on site.
Three ways to put an aircon on solar
- Grid-tied panels, no battery
- The panels feed the house and the grid makes up any shortfall. Good for an aircon that runs in the day, such as a home office or a store. It does nothing during a brownout, because a grid-tied inverter switches off when the grid does.
- Hybrid, with a battery
- The panels run the house, fill the battery, and the battery carries the evening and the night. This is the setup for bedroom aircons, and the one that keeps chosen circuits on in a brownout.
- A solar aircon unit
- Some units sold here take panels straight into the aircon and top up from the socket. They suit one room and nothing else. Read the datasheet for what it draws from each source; we have not read one closely enough to quote figures for it.
Grid-tied, hybrid and off grid, and what each does in a brownout
What people ask about solar and aircons
How many solar panels do I need for a 1hp aircon?
For the Carrier WCARH010EE, a 1.0 HP window unit that draws 930 W, about 3 panels of 550 W cover 6 hours of daytime running at San Fernando. Running it 8 hours a day takes about 4.
Your own unit’s figure is on the plate on its side, in watts. Use that rather than the horsepower on the box.
Can solar run an aircon at night?
Only from a battery. Panels make nothing after dark. A 930 W unit run from 10 pm to 6 am uses 7.44 kWh, and the Deye RW-F10.2 battery holds 9.2 kWh you can use, so one of them runs that unit for about 9.9 hours.
What size battery do I need for a 1hp aircon?
Multiply the plate watts by the hours you want and divide by 1,000. That is the kWh to store. For 930 W over 8 hours it is 7.44 kWh, which fits in one battery of the size on this page with some left over.
Compare it with the battery’s usable energy, not its rated energy. They are different numbers on the same datasheet.
Is solar for aircon only worth doing?
If the aircon runs while the sun is up, a small grid-tied array sized to it does the most for its size, because nearly everything it makes is used on the spot. If the aircon runs mostly at night, panels alone do little for it, and the battery becomes the bigger part of the job.
From one aircon to the whole house
An aircon is rarely the only load, and a system sized for it alone usually ends up short once the fridge, the fans and the rice cooker join in. Send us a recent bill with the kWh figure and say which rooms you cool and when. That is how our residential installations are sized, and the solar panel calculator does the whole-house sum with an appliance added on top.
Tell us which rooms you cool, and when
Send the kWh from a recent bill, the aircons you run and the hours. You will get a written answer with a panel count, a battery size if you need one, and the next step.
Tell us the property and what you are trying to cut, and you will get a written answer with a size and a next step. No visit is booked and nothing is charged for asking.
Sources: aircon plate figures from Philippine dealer specification tabs, read 23 September 2026 and listed on the appliance wattage page; Deye RW-F10.2 product page, read 1 October 2026, for rated and usable energy; Global Solar Atlas, the World Bank Group and ESMAP, on Solargis data, for the sun hours at San Fernando. Named products are examples used for the arithmetic, not a quotation.