Today we will cover commonly asked questions related to Solar generator. Can a solar generator run an Air Conditioner? What solar generator capacity needed to power AC? These are very logical question which we will address in detail in this blog. All your doubts related to this topic will be explained through real life examples and considering commonly used solar home backup in USA households.
Introduction
Air Conditioners are one of the first home appliances which USA homeowners want to keep running in case of power outage, especially during summer heat waves. Moreover, due to frequent grid failures due to wildfires, windstorms, etc many people are moving towards a cleaner and renewable source of energy for household power generation.
We know that solar generators for home backup can power common home appliances TV, LED lights, power banks, ceiling fan, electric kettle, refrigerator, etc. But still may household are sceptical whether domestic solar generators can power different type of AC’s like portable air conditioner, window air conditioner, central air conditioner or not.
So, lets address it in detail using practical USA specific examples.
Can a Solar Generator Run an Air Conditioner? (Quick answer)
The short answer is YES. A proper sized solar generator can run multiple types of Air Conditioners including portable AC’s, Window AC’s and mini split AC’s.
Central Air conditioners are more challenging, but still it can be powered on Solar generators of significant large capacity.
5 Key factors that determine whether AC will work on domestic solar generators or not:
- Running watts of AC (Continuous power requirement)
- Surge watts of AC (Startup power requirement)
- Battery capacity of Solar generator (How long it will run)
- Inverter output capacity of Generator
- Solar panel input (Recharge Speed)
Our complete calculation of selecting best solar generator for Air conditioner will depend on above 5 factors. So, your Air conditioner can easily work on solar generator for home backup if you can design one based on above parameters.
Rule of thumb: If you are buying a solar generator specifically for an air conditioner, check the inverter specifications before looking at battery specifications. Because handling startup surge power is crucial in case of AC’s.
Lets dive deep into each factor using some real life examples.
Understanding Air Conditioner Power Requirements
I will explain each term in layman terms with practical example of each. So that each one of you can design a solar generator for Air conditioning purpose.
Running Watts
It represent the power your air conditioner will consume while operating normally.
Running Watts of different Air Conditioners:
| AC type | Running Watts |
| Window AC | 1000W |
| Mini Split AC | 1400W |
| Central AC | 3500+ W |
In simple terms, if your Window AC runs at 1000W continuously, your solar generator must be able to supply at least that much power without any interruption.
Running watts mainly helps in determining Battery Runtime. Means if you want to know for how much hours your AC will run on your fully charged battery:
Runtime (Hours)= Battery Capacity (Wh) / Running watts
Example:
- Consider battery capacity: 5000Wh
- AC Runtime power=1000W
Runtime hours=5000/1000=5 hours
So, if losses neglected, 5000Wh battery will run 1000W capacity (running watts) Air conditioner for 5 hours.
Surge Watts
Is it sufficient to design solar generator based on only running watts? No not at all. This will cause failure when you will start your air conditioner. But why?
When an air conditioner starts, the compressor requires a sudden burst of power known as Surge Watts.
Surge Watts for different type of Air conditioners:
| AC Type | Running Watts | Surge Watts | Surge Multiplier |
| Portable AC | 800W | 2000W | 2.5x |
| Window AC | 1000W | 3000W | 3.0x |
| Mini Split | 1400W | 3500W | 2.5x |
| Central AC | 3500W | 7000W+ | 2.0x+ |
In simple words, a Window AC of 1000W will require 3000W power during startup (3x surge multipler). So, select inverter capacity such that it can handle the surge power during startup of Air conditioner.
A 1000W window AC may look smaller on paper, but its compressor can demand 3000W during startup (for few seconds). So in such case, we will need a solar generator with inverter output capacity greater than 3000W, say 3500W to be on a safer side.
Most air conditioners require 2-3x more power during startup than during normal operation. This temporary surge of power lasts for only few seconds but it determines the minimum inverter size required.
Battery Capacity
Solar Generator Battery capacity determines:
- Runtime (in hours)
- Overnight cooling capacity
- Backup during emergencies
Battery capacity is similar to fuel tank capacity of a gas generator. Larger the battery capacity of your solar generator, larger will be the AC running time.
Example:
- Consider battery capacity: 10,000Wh
- Window AC Runtime power=1000W
- Runtime hours=10,000/1000=10 hours
Realistically your runtime will be 8-9 hours considering power losses.
Battery capacity does not help if inverter capacity is undersized. Make note of it
Solar Panel Input
Solar Panel capacity will determine how fast the battery of solar generator will charge. This stored power will be utilised to power air conditioner during night.
- More solar panels means faster recharge
- High efficiency solar panels will help to produce power even during low light seasons.
Example:
- Battery capacity is 10,000Wh
- 5 solar panels of 400W capacity (Solar array of 2000W)
So, during peak sun hours, it will take 10,000/2,000=5 hours to fully charge battery.
In reality, it may take 5.5 to 6 hours to fully charge battery of 10,000Wh capacity (considering energy losses)
Without adequate solar panels, battery drains everyday and runtime decreases. So, decent solar array is must
How to Calculate Solar Generator Size for an Air Conditioner
We will design a sample solar generator specification which can power an air conditioner. This calculation will help you to design a custom solar generator based on your requirements.
Lets consider following sample home appliances along with air conditioner which you will power during power outage and emergency situations:
| Appliance | Running Watts |
| Window AC (Air conditioner) | 1000W |
| Refrigerator | 150W |
| LED Lights | 100W |
| Wifi Router | 30W |
| Laptop/Phones | 70W |
Total Running load:
1000+150+100+30+70= 1350W
Total Running load= 1350W
Surge Calculation:
| Appliance | Surge |
| Windows AC | 3000W |
| Refrigerator | 1000W |
| Others | Negligible |
Worst case scenario (All appliances started at same time):
3000+1000+200=4200W
Required Surge Capacity=4200W
Specifications of Solar generator recommended
| Inverter Continuous Output | 2000W Pure Sine Wave |
| Inverter Surge Capacity | 4500W |
| Battery Capacity for powering all appliances for 5 hours=1350W x 5= 6750Wh | 6750 Wh |
| Solar array required=5000Wh/5h=1350W | 1350W (To charge above battery in 5 hr) |
| Solar panel capacity for 1000W solar array | 200W x 5 panels |
AC compressors have ON/OFF cycles. So, even less power will be needed than calculated above. We have considered worst case scenario during calculation.
Above solar generator specifications are designed considering that we will run all appliances at the same time continuously for 5 hours. But in reality, we run only limited appliances at a single time. So, in reality, even 5000Wh battery capacity will be sufficient to power appliances along with air conditioner.
Solar generator Requirement based on AC Types
We will do a comparative analysis of different types of Air conditioners like Portable AC, Window AC, Split AC and central AC.
| AC Type | Running Watts | Surge Watts | Recommended inverter | Recommended Battery | Recommended Solar Panels | Estimated Runtime |
| Portable AC | 800W | 2000W | 2000W (4000W Surge) | 4000Wh | 800W | 4-5 hours |
| Window AC | 1000W | 3000W | 2000W (4000W Surge) | 5000Wh | 1200W | 4-5 hours |
| Mini Split (1 ton) | 1400W | 3500W | 3000W (6000W Surge) | 7000Wh | 1600W | 4-5 hours |
| Mini Split (1.5 ton) | 1800W | 4500W | 4000W (8000W Surge) | 10000Wh | 2000W | 4-5 hours |
| Central AC (3 Ton) | 3500W | 7000W+ | 8000W (12000W Surge) | 20000Wh | 4000W | 4-5 hours |
| Central AC (5 Ton) | 5500W | 12000W+ | 12000W (20000W Surge) | 30000Wh | 6000W | 4-5 hours |
When you are selecting best solar generator for air conditioner, you should go for Portable AC or Window AC (Considering the surge power and overall setup efficiency)
If you are going for Split AC or central AC of high cooling capacity, go for AC output or Gas generators.
Our team have given detailed calculation of different AC types so you can select best solar generator for air conditioning based on your budget and requirements.
Solar generator Vs Gas Generator for Air Conditioners
| Solar Generator for AC | Gas Generator for AC |
| Quiet and nearly silent | Loud engine noise |
| No fuel required | Gasoline or propane needed |
| Best for window AC or split AC | Best for central AC’s |
| Limited by battery capacity | Runs as long as fuel is available |
| No emissions | Produces exhaust fumes |
| Higher upfront cost | Lower upfront cost |
| Can recharge from solar panels | Fuel must for operation |
| Ideal for short to medium outages | Ideal for extended outages but fuel dependent |
Gas generators are better for powering large air conditioners for extended periods, while solar generators are quieter, cleaner and efficient cooling option with zero fuel, zero noise, comparatively less maintenance cost.
Common Mistakes When Running an Air Conditioner on a Solar Generator
9 common mistake when running an air conditioner on solar generator are:
- Ignoring startup surge power
- Buying an undersized inverter
- Focusing only on battery capacity
- Choosing a modified sine wave inverter
- Running multiple high power appliances together
- Oversizing runtime expectations
- Underestimating AC Energy consumption
- Buying an inverter without expansion options
- Installing less efficient solar panels and less solar array than expected
The biggest mistake people make is checking battery capacity first. When powering an air conditioner, always verify inverter capacity and surge rating before anything else
Hopefully all your doubts related to ‘Can a solar generator run an air conditioner’ are cleared. If you still have any question, do let us know in the comment section below.
Frequently Asked Questions (FAQ’s)
Yes, a properly sized solar generator can run air conditioner along with other home appliances such are refrigerator, TV, Wifi, etc. Just make sure that combined surge power of high power appliances is less than inverter surge capacity.
Duration depends on runtime watts of all appliances and battery capacity. So, keep battery capacity (Wh) high if you want longer backup durations.
Yes you can. As far as overall surge power is below inverter output capacity and battery capacity is sufficient enough to provide power. Portable AC and split AC can easily be powered continuously as we have seen in our real time example.
