Whole House Generator vs. Solar Battery Backup System

The United States experiences more power outages than any other developed country. The estimates vary regarding how many households are affected annually due to these outages, but let’s say it’s a lot. And given our nation’s outdated grid system, extreme weather events, and other disaster-related outages (such as wildfires), power outages are not likely to decrease anytime soon. No matter the cause of the blackout, it can create harsh and often dangerous conditions when the grid goes down. However, there are alternative options to being left in the dark. Your best choices are a whole house generator or a solar battery backup system.

But, which choice is best for you? 

Updates to our country’s electric grid would be welcome. But in the meantime, other more immediate and cost-effective solutions are available. A backup power supply is an important consideration. Let’s address the two most viable solutions: whole house generators and solar battery backup systems. 

It’s essential to understand your energy goals when it comes to backup power supplies since both systems will require an investment. To help you decide which power source is the right fit for you, we’ve provided the pros and cons of both!

Whole House Generator

Whole house generator

If you’re looking for a system that can provide emergency power regardless of whether or not you have solar panels, then a backup generator may be the ideal solution for you. Backup generators provide electricity by burning liquid propane or natural gas. If your home has an existing natural gas line, installing a whole house generator is relatively easy. Typically, generators exist outside the house and can be turned on manually or by an automatic transfer switch as soon as the grid fails.

Compared to solar battery backup systems, whole house generators are often more affordable on the front end. However, they require regular maintenance, which means a small recurring cost. They also usually require regular weekly self-tests, and if using propane to fuel the generator, they may need refueling to run during an outage. Of course, refueling your propane tank will need to happen regardless of if you have a generator or not. A well-maintained backup generator will last 10,000 – 30,000 hours or about 3.5 years of consecutive use. 

Here’s an overview of some of the pros and cons of a whole house generator.


  • Overall less expensive upfront project cost
  • Ability to backup more for less cost
  • Ability to backup larger loads (depending on generator size)
  • Ability to backup the whole house (depending on generator size)
  • Backup power, regardless of the weather or status of grid power


  • Consumption of high amounts of fuel LP or NG depending on connection
  • Maintenance
  • Fossil footprint
  • Does not qualify for any federal tax credits
  • Proper location required for unit installation and connection
  • Noise during operation

Solar Battery Backup System

Solar Battery Backup System

Alternatively, solar battery backup systems provide electricity and are charged by a connection to your home’s rooftop solar panel system. The batteries store excess energy produced by the solar panels and save it for later use. 

Solar battery storage systems are popular for their reliability and ability to provide power to your home without interruptions and downtime. Unlike generators, battery backup systems benefit the environment. A solar battery system works best when combined with a solar panel system. However, batteries can still be used without solar and are charged through energy sources like electricity from the grid. 

Depending on the size of your home and your solar system, a battery backup system can be more costly than a whole house generator. However, many battery storage systems qualify for solar incentives like tax credits and can be used to help lower electricity costs by offsetting peak demand rates. Besides, unlike propane or natural gas, sunlight is always free.

Buy a Solar Battery Backup if…

A solar battery backup system is an excellent option for customers who want a backup system that can work with any existing or future solar energy system. A battery system is an excellent option for those who prefer a quiet, low-maintenance, and environmentally-friendly solution.

Consider investing in a solar battery backup system if you want to keep the lights on, power essential home appliances during a grid outage, and reduce peak electricity charges.

Another important consideration is the depth of discharge (DoD), which is the percentage of discharged power relative to the battery’s total storage capacity. If a battery can hold 10 kilowatt-hours of solar capacity, a DoD of 75% means that you can’t reliably draw more than 7.5 kilowatt-hours of clean energy. It’s similar to how modern computers ship with “500 gigs” of storage even though the operating system and pre-installed programs take up some of that hard drive space.

As a general rule, the higher the depth of discharge, the more solar power you can store and use. So aim for DoDs that are 95% or higher. Because of these savings, most solar backup battery solutions have a measurable ROI.


  • Qualifies for federal tax credits when connected to a Solar PV system
  • Smaller footprint/installation area
  • Clean, renewable technology/ operation
  • Requires no fuel (sunlight is FREE) or traditional mechanical maintenance
  • No noise during operation
  • Ability to control and adjust settings remotely
  • Ability to export power to the grid during peak times
  • Partial house or whole house backup (depending on battery storage size)


  • Higher upfront project cost (before tax credits)
  • Whole-house backup requires larger amounts of battery capacity 
  • Battery recharging is affected by weather conditions
  • Limits on what larger loads can run concurrently
  • Typically limited to critical loads in most cases


It’s important to note that solar energy is not required when installing a backup power supply. However, as we’ve noted, whether you decide to install a solar system or not, there are many benefits to installing a home backup power supply. Once you’ve identified your energy needs, it will be much easier to decide which system is the right fit for you!

If you have any questions along the way or need help deciding which system makes the most sense for your home, our team of experts is always here to help!

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