When that dry summer heat hits the South Central and the Rocky Mountain regions, there is only one reprieve for Texans and Coloradans: turning down their thermostat settings and cranking that AC. But for homeowners who want to invest in solar plus storage systems, it’s important to understand how powering an AC unit with solar PV panels and a backup power system like the Tesla Powerwall works before pulling the trigger on the installation.
So, can you use a Tesla home battery to keep your home cool this summer, and for many summers to come? The short answer is yes, but it depends.
Powering Your AC with Solar: It’s All About Planning
The problem with powering your air conditioner using a solar battery backup system is not the energy it takes to run your AC, it is the energy it takes to start it. In order to move the locked rotor of an air conditioner, it requires an energy spike that is higher than the normal operating energy current.
These two different electrical values are known as the locked rotor amps (LRA) and the running load amps (RLA). A typical LRA can be upwards of 8 times the current of the RLA. And even though this increase in electrical current only occurs for less than a second, if your Tesla Powerwall system is not designed for the right output, it won’t be able to get your air conditioner started. That’s where planning and design comes in!
How Long Can a Tesla Powerwall Power an Air Conditioner?
If you know that your solar battery storage system will get your AC unit started, the next question is: how long will it be able to run on your renewable energy?
Tesla has created this handy Powerwall Outage Calculator, which can give you a ballpark idea of how long you might be able to power your home using between 1 Powerwall up to 10 Powerwalls. This calculator also accounts for other energy usage in the home, like showering, cooking, lights, charging devices, and more from low impact energy usage to energy-intensive activities. The more energy you use through the rest of your home, the less you will be able to run your cooling equipment.
How long will a Tesla battery last?
Each Powerwall can hold up to 13.5 kWh of energy. To put that into context, a central 3-ton AC unit running for constantly 3 hours will use 9 kWh. Of course, a well designed cooling system will not run for three hours straight — it turns off and on intermittently to maintain the desired temperature.
Tips for Running Your AC with Tesla Powerwall
Wondering how you can get the most out of your solar batteries while keeping your home comfortable? With a few useful tips, a properly designed and installed solar PV system with Tesla Powerwall will last longer in an outage.
Turn your thermostat setting up a few degrees. Just +2ºF can make a big difference!
If your air conditioner is aging, replace it with a more efficient model like a ductless heat pump.
Reserve other energy consumption heavy activities for the daytime, like laundry and dishwashing that will use power generated from your solar panels.
CAM Solar is an authorized installer of Tesla Powerwall, which can be paired with your system of solar PV panels to keep your home powered and comfortable during an outage. We specialize in properly sizing your solar PV system to meet the needs of your home, and to even exceed your energy goals.