To directly answer your question in general, you will need 1200 watts of solar panels for each ton of cooling power or 20 units of 300-watt solar panels to run a five-ton air conditioner. A solar panel system is a great option for powering air conditioners in homes.
The system consists of solar panels, batteries, and an inverter. The solar panels collect energy from the sun and convert it into DC power. The batteries store the DC power and the inverter converts it into AC power.
The AC power is then used to power the air conditioner and other energy load or requirements. When it comes to solar power, there are a lot of factors to consider in order to estimate how many solar panels you’ll need to run your air conditioner.
We made a list of factors right here and also watch out for some fun facts about your airconditioners right at the end of this article.
Factors That Determine the Power Consumption of an AC
The first and most important factor is the amount of power your air conditioner unit uses. This will also give you information about your cooling device’s cooling capacity. You can find this information on the yellow EnergyGuide label affixed to your appliances.
Power output is simply calculated by this formula. Multiply the number of Ampers(current) with the number of Volts or P(Watts) = I(Amps) x V(Volts)
Example : P = 10A X 140V = 1,400W
Here are some useful power rating and wattage guides for common types of air conditioning units from PickHvac:
How Many Watts Does a Portable / Window Air Conditioner Use?
How Many Watts Does a 1 – 5 Ton Air Conditioner Use?
How Many Watts Do Air Conditioners Use?
The number of watts an air conditioning unit uses is affected by two key factors:
AC Size – The higher the BTUs the AC has, generally means the more watts it will use. For example, a 5,000 BTU window air conditioner uses much less energy consumption than a 14,000 BTU portable air conditioner and a 48,000 BTU central AC.
AC Efficiency – Air conditioners widely differ in how they use electricity efficiently to move heat. Mini split and central air conditioners are generally the most efficient. These types use less power per BTU. Some newer air conditioners of all types are also more efficient than their old version.
Solar Panel Efficiency
Next, you’ll need to take into account the efficiency of your solar system. Solar panel efficiency is the percentage of sunlight that is converted into electricity by a solar panel. Solar systems are usually about 20-30% efficient, so you would need 6-8 panels per 1,000 watts of AC power.
Here are some tips on how to make more out of your existing solar panel system:
1. Keep away from the shade. A shade over your solar panels could end up losing up to half of your solar efficiency for each panel that is shaded. Be very careful in choosing your installation site and make sure that your roof space is clear of any shade or shadow.
Choose a location away from tall structures like a building or tall trees.
2. Do not let dirt build up. Yes, dirt and soil on your panel can affect its efficiency. According to U.S DOE, accumulated dirt over your panel can result in a 10% loss in energy yield. Clean your solar panels regularly.
Air Conditioning System Efficiency
Air conditioner efficiency is often related to the energy efficiency ratio (EER). The EER is a ratio of the cooling output of an air conditioner divided by the energy input required. A higher EER rating indicates a more efficient air conditioner.
In general, air conditioners with an EER of 9 or above are considered to be high efficiency.
To calculate how much power your air conditioner needs using BTU and EER, divide the BTU by EER rating
or P(Watts) = BTU ÷ EER
Sample calculations :
P = 5,000 BTU ÷ 10 EER = 500W
P = 5,000 BTU ÷ 8 EER = 625W
To power 5,000 BTU window air conditioner with 10 EER rating requires 500W power, much lower than the one with 8 EER ratings. Calculation shows the difference, the higher the EER rating the lower your power requirement. Which in a way saves you money on energy cost.
Next time you shop for an air conditioning unit, look for one with a higher EER rating.
Location and Weather
You need to consider the amount of sunlight your location receives. The average daily sun hours will give you a good estimate of how much power your solar panels can generate.
The average location gets about 4 hours of peak sunlight per day. So, for a 5,000 watt AC unit, you would need 30 panels installed to get enough power to run the AC for 4 hours per day.
While living in a hotter part of the region is a good idea to collect more solar energy, this also means more air conditioning is needed.
In cooler weather, the temperature is low thus, the air conditioner will not have to work as hard to cool a room or a house, and in warmer weather, temperatures are much higher then in this case, the air conditioner will have to work harder.
This can greatly affect the amount of energy that is used by the air conditioner, and the amount of money that is saved on your energy bill. On cloudy days you will need a backup power source like a battery bank or a generator.
Solar energy storage is the best solution especially if your power usage is high, or if you have a lot of other things running on your solar system. The difference between a battery bank and a generator is that a generator creates electricity while a battery stores electricity.
A solar energy storage system can be used with air conditioning systems in any type of application may it be for home, RV, or business.
Fun Facts About Air conditioners:
- Did you know? Your air conditioner probably requires more watts to start than it does to run. A lot more, in most cases. For example, according to this generator dealer, a 24,000 BTU AC needs 6,000 watts (6kW) to start but just 2,000 (2kW) to run. It’s about 3 times more for most AC sizes; Not exactly 3 times as much, but that’s a pretty close figure.
- Did you know? You can save 20% on your energy bills each year. FACT! If your cooling system is more than 12 years old and needs replacing, consider purchasing a new, energy-efficient system. Depending on where you live, replacing your old heating and cooling equipment with ENERGY STAR qualified equipment, conducting maintenance, and properly sizing and sealing your ducts can cut your energy bill by as much as 20%
Going green and using renewable sources of energy like solar power to run your air conditioner at home or in your office is one way to help the environment. Though they might result in higher investment costs, you can recover them later.
More importantly, putting all of these factors together will give you a good estimate of how many solar panels you’ll need to run your air conditioner. However, keep in mind that these are only estimates and your actual needs may totally look different.