Powerwall vs. Backup Generator

Be prepared for the next storm or power outage with quick backup protection from Powerwall while also reducing your electricity bills. Explore the following to help you understand and decide on a backup solution for your home:  

What is Powerwall

Powerwall is Tesla’s fully integrated, rechargeable home battery that stores energy daily from solar or the grid to back up your entire home during an outage. When a power outage occurs, Powerwall automatically detects the outage and instantly powers your home with stored backup energy.

Powerwall can be installed indoors or outdoors, wall-mounted or floor-mounted, paired with solar or without and operates in both very cold and hot temperatures.

What is a Backup Generator

A backup generator is a device powered by fossil fuel such as liquid propane, diesel or gas to power your home during an outage. Depending on the size of the generator, it can provide power for your home while fuel supply lasts.

A backup generator is mostly installed outdoors, requiring additional construction work. It may require regular maintenance, as they are used infrequently, to ensure they are functional and have adequate fuel.

Cost Savings of Powerwall vs. Backup Generator

Providing Monthly Value Beyond Backup1

Lower Ten-Year Cost of Ownership2

When paired with solar, Powerwall works daily to reduce your monthly electricity bill. Over ten years, these savings can make Powerwall and solar more cost effective than a generator.

Powerwall creates savings by storing excess solar energy to power your home. Powerwall, paired with or without solar, can be set to increase savings with Time-Based Control, using smart charging and discharging to maximise the economic value of your home energy system. 

Differences Between Powerwall and Backup Generator

Powerwall Backup Generator
Experience Automatic, < 1 second transition to back up 15-30 second delay, before automatic or manual backup
Energy Source Stored electricity from solar panels or the grid Natural gas, liquid propane or diesel
Noise Quiet (< 40 dBA at 1 meter)3 Louder (77 dBA at 1 meter)3
Installation Indoors or outdoors, wall-mounted or floor-mounted Outside, generally on concrete pad, due to odor and exhaust
Maintenance Minimal Refuel, servicing and oil changes
Financial
Value
Reduces your electricity bill by storing solar or energy from the grid when prices are low Has no effect on your electricity bill
Warranty 10 years 5 years
Environmental
Impact
Powered by the sun Produces toxic fumes that may expose customers to hazards like carbon monoxide poisoning4

Next Steps

Be prepared for the next power outage and get started by requesting a Powerwall quote. You can also sign up to receive the latest on Tesla news, events and product updates.

Additionally, explore resources to understand how Powerwall works:

1 Comparison of a 16kW backup generator versus an 8kW solar system with 1 Powerwall financed with a 10-year loan at 12% APR.

2 Analysis assumes typical household electricity consumption and solar production of the climate region (13,300 kWh and 9,900 kWh, respectively) and Eskom time-of-use rates. Generator operation is based on grid outage trends in South Africa from 2019 to 2023. Actual results will vary based on location, household energy usage, utility rates, load-shedding frequency and other factors.

3 According to the Bureau of Transportation Statistics, a refrigerator humming sound level is approximately 40 dBA while a vacuum cleaner level is about 70 dBA.

4 FEMA provides safety tips when using generators at home including being aware of the following hazards: carbon monoxide poisoning, fire and electrocution.