How Many Solar Panels To Run Air Conditioner?

Run air conditioner with solar panels

For most home appliances, it’s pretty easy to determine precisely the number of solar panels you’ll require for them to operate.

This is because they draw a constant current, which means that when you know an appliance’s power rating in watts, you can relate this to the output power of the solar panel in amps and watts.

Some appliances, such as refrigerators, freezers, air conditioners, and freezers, aren’t so simple because they have compressors powered by motors. This means that the amount of power they draw can vary and must be weighed out.

How many Solar Panels to Run an Air Conditioner?

How many solar panels do you need to run an air conditioner?

An air conditioner will require 1200 Watts worth of solar panels to cool a Ton, with an irradiance of 4 peak-sun-hours/day. Therefore, a battery of 100AH is recommended per Ton for every hour of the scheduled duration of the operation. This allows for running even at low irradiance and serves as the motor with a reservoir for surge current.

These are the points we must know before creating the solar system that can run an air conditioning unit:

  • The reason air conditioners are classified in tons
  • AC power rating (kW)
  • What are Power factors and surge current?
  • When will your air conditioner continue?
  • Are batteries required to power your air conditioning unit?
  • What kind of batteries are the best for solar energy storage?
  • What amount of energy do solar panels produce?
  • Solar panel sizes that you’ll utilize
  • Inverter Sizing (and the reason why you should have one)

Solar-powered cooling is a great option, especially in hot and humid temperatures and lots of sunshine!

Solar AC does a great DIY project. First, we must study AC electric and cooling features before answering the question of “How many solar panels will I require to power an air conditioner unit?“.

Can you run the air conditioner off solar panels?

In the case of d.c. Loads power calculations are simple. The power rating can be calculated by multiplying amps x volts.

For instance, if you are calculating the power of a d.c. Resistance load comes from a 12-volt supply and draws 12 amps. We apply this calculation to determine the power:

12V * 12A = 144W

For a.c. circuits the equation volts x amps may not always mean the watts (although occasionally it can!)

How much power does an air conditioner use?

Air conditioning connection diagram using solar panels
Air conditioning connection diagram using solar panels.

Why is AC rated in tons and not watts?

Each air conditioner has various efficiency and, therefore, should we consider its electrical Kilowatt rating to make a comparison, it wouldn’t be able to reflect their cooling capacity.

This means that two AC units with a rating of 1.5 kW may not provide the same cooling power.

What is the definition of a ton of AC ratings? It’s what amount of coolant is needed to melt around 2000 pounds worth of ice one day. It is commonly referred to in the trade as a short ton.

The greater the amount of air cargo, the greater the amount of air that can be cooled every hour. A ton could be described in terms of 12,000 BTU/h (British Thermal Units per Hour) as well as 3.5 Kilowatts (kilowatt).

That means that a Ton air conditioner has a cooling power in Watts

(12000BTU x 1055) / 3600 = 3516 Joules per sec = 3516W (cooling)

What is the EER value in AC?

EER refers to the ‘energy efficiency ratio. It shows how efficiently the air conditioning unit cools. When you divide an air conditioning device’s BTU number by its electric rating of Watts, you will get the ratio that shows its effectiveness.

A dependable air conditioner might have an EER of 11, for instance. AC units with an EER rating greater than 10 are suggested in areas with hotter climates.

It is the EER scoring system built around an ambient temperature of 95deg, an indoor temperature of 80degF, and 50% humidity.

It is more prevalent these days since it considers the air conditioner’s capacity to cool over an array of temperatures. The S indicates that the ratings are seasonal.

The table below displays the SEER/EER figures for the most popular home AC units.

Lennox is creating significant advancements in their designs by combining them by incorporating solar panel support, and it is likely to be the norm shortly.

What’s the price per hour to operate the air conditioner?

This could differ quite a bit and is contingent on a variety of variables:

  • What is the efficacy of the AC unit?
  • How often throughout the day do you test it?
  • How long has your AC been running
  • The outside temperature is outside.
  • The amount for each kWh of your electric power

As you can see, it is possible to be a bit complicated, but is it worthwhile to go deep into this? First, let’s take a look at the aspects you should know about.

The air conditioning and solar installers are required to follow guidelines to help them size their systems. For example, one of them stipulates that an air conditioning unit draws about 7 amps per one Ton of its cooling capacity.

This changes as the Tonnage increases or decreases. It is widely acknowledged that the relation between amps and tons alters as the power of cooling increases.

  • 2 tons equals 15 amps
  • 3 tons equals 18 amps
  • 4 tons equals 21 amps

To determine the proper size and installation purposes is a great idea. In my case, when I’m planning the layout of a solar system, I’d like to know what’s happening electrically!

It is possible to get confused by the RLA (Rated Load Amps), which can be located on the label of the air conditioner tag. See below for an example:

This RLA amount is not an AC operating current but the maximum amount of current that the compressor motor can draw while operating. The AC unit is in operation.

Furthermore, this is not identical to what is known as the LRA amount, which can be described as locked rotor amps. This is because the compressor motor is stuck, cannot rotate, and draws maximum current.

This is identical to the surge or inrush current at the point that the compressor is standing still.

The actual operating current is contingent on other variables.

Current from the air conditioner

Once it is time for an a.c, the motor is started, it draws many hundred times higher currents than it does when running continuously.

The loads determine the running current. However, the surge or inrush current is the most amps the motor draws if the engine is fixed and cannot move (this is extremely dangerous.)

The wire’s length is determined by the maximum current at which it runs and then 10 percent. This is because the surge currents are only for just a few seconds in normal circumstances, and the heat effect on the wiring isn’t that significant.

Fuse and breakers should be sized to take the surge without going out.

This is also a significant issue on all solar panel systems intended to operate air conditioning.

If it operates during the daytime without a battery bank to act as an energy reservoir and your solar panels’ power rating must be large enough to provide the motor the surge current.

Solar panel systems designed to run home appliances make use of a device called an inverter that converts d.c. (direct current) voltage created by solar panels to a.c. (alternating voltage) electricity for home-usage.

How many solar panels power ac units?

We’ve now looked at what happens inside an air conditioning system on the side of the load, and we’re now able to examine that supply aspect in more depth.

This is why I’ll base the remainder of this post on 300-watt fixed solar panels, as the higher ratings are the best value for installed dollars per watt.

How much power can a 300-watt solar panel generate?

The solar panel’s power output in Watts is contingent on these elements:

  • solar panel efficiency (monocrystalline panel efficiency is between 20% and 22%)
  • solar panel area in square meters
  • Irradiance (the solar energy that is dependent on the location of your home)
  • direction (what does the angle between vertical and horizontal)
  • Are you making use of the fixed as well as auto-tracking for your solar installation?

The solar panel ratings provided by the manufacturer adhere to the guidelines laid out within the Standard Test Conditions, or STC.

The panel rating is determined if the solar radiation exceeds 1,000 watts /m2 and 25 degrees C.

It is assumed that it’s directly beneath the sunlight at 90°, which isn’t always the case!

The solar panel’s output decreases as the sun’s angle gets more acute. It also decreases in other angles when the temperature is higher than 25 degrees Celsius.

Its power consumption is reduced by 0.5 Watts for each degree increment in temperature.

If solar energy is low due to irradiance at your location, the solar panels’ output is likely to decrease proportionally.

Don’t miss my review of the best 300 watt solar panels for home and rv at this link.

How does a solar inverter work?

Solar panels generate direct current (d.c.), home appliances require alternating current (a.c.), and that’s why you’ll need an inverter that converts d.c. into a.c.

Inverters break up direct power into pulses or packets and transform them to create a perfectly sinusoidal waveform just as the force-fed to your home by utility companies.

How many solar panels to run a 5-ton ac unit?

The need for air conditioners is in the hottest times, and that’s the time of the day, which is during the noon hour in most places.

This is a chance to catch a lucky moment, as it’s same time the sun’s energy is at its peak, and the solar panel output is at its highest.

1 Ton of cooling capacity for air conditioning is around 1.2kW, so if it ran for four hours, it would use 4.8 kWh during that period.

The way to think about it is that a five-ton air conditioner will consume:

4.8kWh 5x = 24kWh

A 300-watt solar panel could generate 300 watts divided by 4 hours during the same period (if the conditions for sunlight are perfect), which is equivalent to 1.2kWh.

The most basic formula to determine the amount of solar panels needed to run a five-ton AC device is:

AC energy consumption (24 kWh)/energy produced (1.2 kWh) = 20 solar panels (300 watt rating)

How many solar panels to run a 2-ton ac unit?

We will operate an AC for four hours and then turn it off at the hottest time during the day.

The calculation is as follows and assumes continuous running with surge currents ignored:

9.6 kWh/1.2kWh equals 8.8 solar panels (300 watts)

Can I run a 1.5 ton AC on solar without batteries?

The smallest AC units are simpler to power with solar panels. The most basic calculation for the calculation of a 1.5 ton unit of air conditioning is

7.2kWh/1.2kWh equals 6 (300 power ratings)

This means that you can run a 1.5 Ton AC unit using six 300-watt solar panels as long as the sun shines!

So what’s the deal with the AC inrush?

The current of inrush is pulled when the compressor is moved from a stationary position, such as when it begins one of its compression cycles when the temperature decreases.

Beginning when the motor is cool is the worst scenario, and when this happens, the engine might pull three or four times its standard current. In reality, it’s better to think that it’s pulling four times to ensure safety.

That means that a five-ton air conditioner might require four founts more energy to start the cycle. This would mean the installation of more than 80 solar panels!

This is not practical, and so what’s the solution? What happens if you run the AC unit during the sunny afternoon or at night?

The solution is to install a bank of batteries to provide energy storage. This provides more power when needed and will allow you to use air conditioning even when there’s no sun.