Determine if you need partial or whole home backup!

Learn the difference between partial and whole home backup using Tesla and Enphase batteries and how to determine your storage needs!

Covering your electrical loads

Understanding your loads is the most critical aspect of sizing your battery backup system. The electricity demand of your loads relates to the breaker size that feeds the electricity to the home load.

Battery Energy Storage Systems have a rated output current that determines what size of breakers it can power per battery. I will compare the grid-tied Enphase IQ10T and Tesla Powerwall batteries and their backup capabilities.

Battery backup capacity

Transparent background image of Enphase IQ battery 10T energy storage system

Enphase IQ10T battery

Enphase IQ10T batteries have a 10.08 kWh storage capacity and 20A continuous output current.

IQ Batteries are not limited by a solar-to-storage ratio because of their ability to limit the solar panel’s output by communicating to the Enphase microinverters.

Tesla Powerwall

Tesla Powerwall 2

Tesla Powerwall 2 packs a punch with 13.5 kWh storage capacity and a continuous output current of 30A.

Powerwall design must consider a solar-to-storage ration of 7.6kW AC to safely charge the batteries during high solar energy output.

Partial backup

You can cover a maximum of 120A worth of breakers with partial home backup. The caveat is that depending on the battery manufacturer, only a maximum size of a single breaker can be backed up. As long as that breaker doesn’t exceed the continuous output current of the battery, it can be backed up under a single battery.



A Powerwall battery can backup a 30A breaker

An Enphase IQ10T can backup a 20A breaker

Whole home backup

Whole home backup means we are covering 200A worth of breakers. This means you are installing at least two batteries. You can add the continuous output current to cover larger breakers with two or more batteries.

Two Powerwalls can cover breakers of up to 60A

Two Enphase IQ10T can cover up to 40A, three are needed for 60A breaker coverage

Finalizing your energy storage system size

Getting started with your first energy storage system is no small endeavor. Fortunately, by planning, you can set yourself up to expand your battery storage capacity or prepare your existing electrical setup for battery installation.

Please get in touch with us if you’d like to discuss your potential battery storage system and how it fits your needs, and we’ll find the best solution for you!

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Manuel Larrain
Manuel Larrain is a Chilean-born US citizen who studied business and sustainability at Western Washington University. Solar energy is his passion, as it is transforming how Washingtonians power their lifestyle. He believes we can address climate change, environmental justice, and steward a brighter future for all of us through renewable energy.