Can Solar Power Run an Air Conditioner?

The summer sun can provide some much-needed warmth after long and cold winter months, but it can also become uncomfortably hot. On those muggy days when you're looking to beat the heat, you can turn the sun's energy against itself and use it to power your home's air conditioner.

Solar power can easily generate enough electricity to power your AC unit, but how it operates will depend on what type of system you use. The two types of solar power systems available are on-grid and off-grid. Each one works a little differently but can provide you with the necessary energy to stay cool.

Running AC with On-Grid Solar Power

The most common form of solar power is on-grid systems. These types of solar power work in tandem with your local power grid. This means if your solar panels aren't generating enough energy to run your home, the system can draw power from the grid to supplement it. Alternatively, if your system is generating more energy than you require, the excess amount will be pumped into the grid, and energy companies will pay you for it. To run an air conditioner with an on-grid system, you'll need several pieces of equipment. Your system will require several high kilowatt panels, a smart meter, a breaker panel, and an inverter. As long as you have the necessary equipment, your on-grid solar power system should have no problem running an air conditioner.

Running AC with Off-Grid Solar Power

Off-grid solar power systems aren't tied to your local power grid. This means your home is run entirely on the energy your panels produce but you won't be able to draw extra power from the grid if you need it. This makes running an AC with solar power a bit more challenging, but not impossible. If you want to run AC using an off-grid system, there are a few steps you'll need to take.

1. Determine How Much Power Your AC Needs

Figuring out how much solar energy you'll require is a necessary step for all your appliances, not just your air conditioner. It's only by determining this amount that you can ensure your solar power system will provide enough energy to run your home.

To figure out how much electricity your AC unit uses, first find how much electricity it uses per hour then multiply that by however many hours you plan to run it each day. Most central AC units will use between 3 and 3.5 kilowatts per hour, but small window AC units may only need 500 watts an hour.

Let's say your unit uses 3 kW each hour to run and you plan to use it for 12 hours a day. That means your solar system will need to generate 36 kW each day just to effectively run your AC.

2. Figure Out How Many Solar Panels Your AC Requires

Since different air conditioners use different amounts of energy and solar panels can generate varying amounts of electricity (between 250 and 400 watts per panel), the number of panels needed to run an AC for each home can fluctuate quite a bit. Then you also have to factor in how long you plan to use your air conditioner each day.

So, if you have an air conditioner that needs 3.5 kW a day to run, you would need 15 separate solar panels capable of generating 250 W each.

3. Install Solar Energy Batteries

Many standard solar power systems don't include a form of storage. That means any excess energy produced by your panels each day is going to waste. Since AC units can use up quite a bit of electricity, it helps to have a battery system installed that can work as a backup. That way, on days when your solar panels aren't generating the required amount, they can draw on the energy stored in your battery.

4. Choose the Right Inverter

Air conditioners draw a lot of energy, so, if you're using an off-grid system that doesn't have the benefit of drawing from the grid, you want to make sure you get a capable inverter. No inverter works at 100% efficiency but you should try and find the most efficient model you can. Sub-par inverters can cause your system to lose up to 50% of the total energy generated by your solar panels. When dealing with air conditioning units run by solar, this is far from ideal.