People are more energy conscious than ever before. Thousands of folks move “off the grid” every year and the rest of use are turning to solutions to high energy consumption like buying efficient HVAC equipment, appliances, automobiles and more.
A question we get a lot is, “is a solar powered air conditioner possible?”
Yes it is. Definitely.
The Current State of Solar Powered Air Conditioning
That’s what this post addresses.
There are two ways to achieve solar power air conditioning.
1. If you outfit a home with a photovoltaic solar power system with enough capacity, it will supply plenty of power to run any air conditioner you choose – central AC, ductless AC, window AC, portable AC, etc.
This is not what this article is about.
2. Air conditioners designed specifically to work with solar energy. This is the focus of the content below.
Solar Air Conditioner FAQs
These cover the basics. Afterwards, we discuss the three power options for solar powered ACs, the cost of solar air conditioning and top solar air conditioner brands.
What is a solar powered air conditioning system?
It’s an air conditioner powered by energy harvested from the sun. It is sustainable, and with every year that passes, solar energy becomes more affordable.
Current cost averages $2.50 to $3.00 per watt. A 6,000 watt system costs about $15,000 to $18,000 for panels, battery, inverter and wiring. That size system would power most homes, not just the AC. We’ve pegged the cost of solar AC only at $6,000 to $10,000.
Not all solar powered air conditioners require batteries and/or an inverter. They are DC or Direct Current air conditioners.
How many panels will I need?
It depends on the capacity of the air conditioner.
Solair World is a major manufacturer of solar power air conditioners. It provides, and most manufacturers do, the recommended number and capacity of panels.
For example:
The SW-HYBRID-09 9000 BTU needs 650 watts, so two 330W panels would power it.
The SW-HYBRID-24 24000 BTU needs 1,600 watts, so five 330W panels are recommended.
There is more information on this below when climate factors are discussed.
How much does a solar powered air conditioner cost to operate?
Anywhere from $0 to a few dollars a month.
Why would it cost anything? In some systems, electricity is needed to run the fan in an indoor unit in a ductless system or similar.
Another way to put it is that you can reduce your energy consumption for air conditioning by 80% to 100% based on your system type.
How does solar powered air conditioning work?
It works great! That’s one answer. A better answer follows.
Solar panels, usually photovoltaic panels (PV panels), collect sunlight in their cells. The panels turn the sun’s energy into electric power.
This is DC power, and if you choose a DC air conditioner, the panels can be wired directly to it.
Most AC’s are AC power – that’s confusing. Most air conditioners require alternating current power. That’s better. So, the DC electrical power must be converted using a device called an inverter. The components of common solar AC options are described below.
Why do some systems have batteries?
Batteries are used to store any excess energy that is used. The stored energy can power the AC after the sun goes down and the panels stop producing power.
Which systems need batteries?
If you are completely off the grid, then batteries are essential. You will also want them if you run your AC after sunset, which many homeowners do in hot climates, especially those with high humidity, since the heat sticks around longer after sunset.
How much battery power is required for solar AC?
It depends on the amount of sunlight, the voltage of the batteries (48V are most efficient) and the amount of power your AC needs to run.
Check the wattage needs of your AC. It should be listed on the small metal label on the back or side.
Calculate how many kWh (kilowatt hours) you need per day. One expert gives this example, “you need a solar air conditioning unit to run for 8 hours a day, kWH can be estimated by multiplying the Wattage marked on the air conditioning unit by the number of hours, in this case 8, then dividing by 1000.” That equation will give you the number of watts you need per day.
When you start working with a local solar power company, it will do a calculation to determine the amount of battery power you’re going to need based on AC size, hours of use on the hottest days and the number of hours of daylight is typical where you live.
And while solar panels can generate some energy on cloudy days, the volume is less. Therefore, your climate will be considered. You’ll need fewer batteries in Denver with 115 days of sun, for example, than you would in Houston with just 90 days of sun.
How large a system is required to run air conditioning?
This is a complex issue based on home size, AC size, climate and how much you plan to run your solar power air conditioner. A solar AC contractor or experienced sales agent can help you with exact system requirements based on a load calculation for your home.
Not all areas of the country are equally sunny, of course.
This affects the capacity of the panels needed.
As a result, the solar industry has developed something called the Solar Production Ratio of solar panels. It is a number used to determine how many hours of electricity your panels will generate at peak performance.
Your solar power contractor will determine how many kilowatt hours will be needed to run your system. The number is based on the length of the cooling season and the average number of hours per day the AC will run.
This is where Solar Production Ratio comes into play. The number of kwh – kilowatt hours – you need to run your solar air conditioner is divided by the Ratio to determine the size/panel capacity you need.
For an example, let’s take 1,500 kWh per year. Here are system sizes you’d need in various regions of the United States.
| Region | Production Ratio | Watts Needed |
|---|---|---|
| Southwest | 1.7 | 880 |
| California | 1.6 | 940 |
| Rocky Mountains | 1.5 | 1,000 |
| South/Southeast | 1.35 | 1,110 |
| Northeast | 1.2 | 1,250 |
| Pacific Northwest | 1.15 | 1,300 |
Solar Powered Air Conditioner Types
It turns out you have three options – AC power, DC power and Hybrid air conditioners that can use either. There are pros, cons and special requirements for each.
DC Powered Solar Air Conditioners
DC solar air conditioners are also called conventional solar powered air conditioners.
Solar panels generate DC current electricity. Here are the pros and cons:
Pros
- DC solar air conditioners can be direct-wired to the panels without converting it.
- Batteries can be added to the system to store excess solar power produced, but only if you have enough panel wattage to run the air conditioner and store energy.
- DIY installation is easier with this type. If you hire a pro, installation cost is less.
- Systems are easy to maintain.
- They are ideal for off-grid use – but only if you add the extra equipment described in the “cons.”
- DC solar ACs are easy to maintain.
Cons
- A DC-powered solar air conditioner needs batteries, an inverter and solar charge controller to work in non-daylight hours – so it costs more than an AC unit.
- A vacuum pump is usually needed to charge the system with refrigerant if/when needed.
The bottom line is that if you’re off the grid and are OK with no air conditioning after dark, a DC solar air conditioner is a good choice.
AC Powered Solar Air Conditioners
AC solar powered air conditioners are also called inverter air conditioners.
An inverter must be used with these systems to convert DC current to AC current. Batteries can be used in AC systems to store excess sun energy.
Your other option, if you are on the grid, is to tie the panels into your electrical panel.
Pros
- Equipment cost is lower than most DC systems.
- Being on the grid gives you three options. You can power household lights, appliances and other items requiring electricity if the panels deliver enough power and/or when the air conditioning isn’t running.
- Secondly, if you have the right type of meter from your electricity provider, you can push excess electricity from the system back onto the grid – and get paid or credited for it.
- Thirdly, on very overcast days, the panels might not make enough power for the AC. At night they won’t make any. In those times, you can run the air conditioning with power from the grid.
Cons
- They don’t work off the grid.
AC/DC Hybrid Solar Powered Air Conditioners
Hybrid systems that use either AC or DC power are quite popular. They aren’t connected to the grid, so no excess energy is pushed onto it. It is sometimes said that they run on solar power and AC power. DC power is meant by solar power.
The unit will take electricity from the grid when necessary – nighttime or during very overcast days when little solar power is being generated.
Pros
- Uses DC direct from the panels or AC through an inverter.
- Easy setup and installation.
- Does not require an inverter or batteries.
- Most have remote controls.
- Some of them are heat pumps, so provide heating too.
- Some use plug and play connections to the wiring coming from the panels and to the electrical panel.
Cons
- Batteries are not compatible with most of them, so if you need power at night, you’ll have to buy if from the grid. However, a few are compatible with batteries.
- While easy to install, we recommend pro installation due to the required connection to your home’s electrical panel.
- Won’t work at night if installed off the grid.
How Much Does Solar Air Conditioning Cost?
For most homes, the complete system starts at about $6,000 but can exceed $10,000 based on size and where you live.
A rough cost breakdown looks like this:
- Solar air conditioner: $1,000 – $2,700
- Photovoltaic panels: $500 – $1,100. They are $250 – $350 each with two or three needed for the AC.
- Wiring: $50 – $200 based on panel location (roof/ground – distance from the house)
- Inverter/Batteries/Charge controller: $1,800 – $3,500 based on specific needs of your system.
Total Equipment Cost: $3,300 to $7,500
Pro Installation Cost: $1,500 – $3,500
Total Solar Air Conditioning Cost: $4,300 to $11,000 for most brands.
Top Solar Air Conditioner Brands
There are a growing number of solar AC manufacturers. Here are the current top selling brands to consider because they make quality equipment.
Solair World
This leading solar AC brand makes a range of models. These include Off Grid DC units, Hybrid AC/DC air conditioning systems and several AC ductless and one ducted system. Solair World uses Mitsubishi and other top brands of compressors.
Gree
One of the top ductless air conditioner and heat pump makers also makes solar units.
The Gree – Solar Hybrid Hi Wall Inverter Air Conditioner / Heat Pump uses inverter technology for AC power from the grid. It can also be powered directly by the panels. It is available in 9K and 12K BTU models.
Lezeti
This brand makes a hybrid solar powered air conditioner. Like the Gree, it can run on DC current directly from solar panels or on power from the grid when needed. Top SEER is 35 – that’s very efficient.
Lennox SunSource
All major air conditioner brands will run off power generated by solar panels – if the panels feed and electrical panel the AC is connected to.
Only Lennox makes a system designed for use with solar panels. It’s the only full-size split system vs ductless mini split system.
The Lennox SunSource complete system with an AC or heat pump, indoor air handler or furnace plus the panels and installation equipment starts at about $14,500 and can run as high as $18,500 based on number of panels and AC or heat pump size.
Event Horizon Solar & Wind
One of the pioneers in solar energy use, this brand makes the ACDC12C air conditioner and heat pump. It is designed for off-grid operation, but will pull power from the grid at night or on very overcast days. It requires about 750 watts, such as three 250-watt PV panels.
More to Come
This is a rapidly developing market, and we’ll keep up with it.
Thank you for stopping by Pick HVAC. There’s a ton more information here, so enjoy browsing our professionally written, information-loaded pages.
Image Credit:
Solairworld
Kingtecsolar
Thank you Rene for this article . It’s very technical but well laid for the non professionals.
With all honesty I thought you are one of the few meticulous engineers I ever seen.
Thank you again