Solar Battery vs. Generator: Which One is Best for My Home?

By Tim Henderson

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Last Updated on November 12, 2020 by Scott Laskey
Nov 12

When the power goes out in your area, what are your options? Unless you have backup power at your home, sitting in the dark is your only choice.

Fortunately, dozens of backup power options are available to choose from – including propane, diesel,  natural gas-powered generators, and solar battery systems. When you find the right solution for your home, you get the peace of mind that comes with knowing your household will keep running, even if the grid goes down.

Here at Sandbar Solar & Electric, we’ve helped thousands of homeowners turn to solar and battery backup on the San Francisco Bay Area and Central Coast in California, so we know a thing or two about the value of a good backup system.

In this post, we’ll discuss the differences between solar battery backup systems and generators and help you understand which is right for you.

Let’s dive in!

What is a Generator?

power generator

Generators and solar battery systems both provide backup power in the event of an outage. The way they do it, though, is very different.

Generators are the type of backup power systems most people are familiar with. Today, most generators run on liquid propane, natural gas, or diesel.

Freestanding generators sit outside the home and either turn on manually or include sensors. Included sensors detect outages and turn the generator on automatically.

Compared to solar battery backup for power outages, generators are more affordable on the front end. Despite the low upfront cost, though, generators require regular maintenance and typically come with small recurring costs. They require weekly self-tests, for example, and need continual refueling to run during outages.

When a generator is maintained well, it will last for 10,000-30,000 hours or about 3.5 years of consecutive use.

Here are a few of the pros and cons of backup generator systems:

Pros:

  • Generators are more affordable upfront than solar batteries. However, solar batteries save a household money over time and there are many rebates and incentives available that can lower the upfront cost.
  • Generators are easy to connect to existing natural gas lines.
  • Generators provide round-the-clock power, as long as they have an ample fuel supply.
  • Generators are available in a variety of sizes, from small, portable units to whole-home systems.

Cons:

  • Most generators are noisy to operate.
  • Even high-end generators require annual and monthly maintenance.
  • Generators require fuel to operate, which means they are not eco-friendly.
  • Fuel left too long in a generator can go stale, causing problems with the equipment and additional repair costs.
  • Generators create emissions during operation, creating an unpleasant smell and a high carbon footprint.

What is a Solar Battery Backup?

solar battery backup

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

Some of the most common types of battery backups available today include:

  • Tesla Powerwall
  • LG Chem
  • Panasonic
  • Generac

Solar battery storage systems are popular because they are reliable. In the event of a power outage, a grid-tied system will shut off entirely, and you won’t have power.

Alternatively, when the grid goes down, a solar-powered battery backup system will draw stored energy from the batteries to power your home with no interruptions or downtime.

In addition to providing unparalleled reliability, battery backup systems also benefit the environment. Learn more about how solar battery backup systems work in our recent post on the topic.

Pros:

  • Battery backup systems operate almost silently.
  • When combined with solar, battery backup systems run entirely on renewable energy, which means you don’t have to spend money on dirty, expensive fuels.
  • Battery backup systems increase your home’s daily solar consumption.
  • Installing a battery backup system can increase the value of your home.
  • Some systems qualify for state and federal tax credits in California.
  • Battery backup systems offer low maintenance requirements and a long lifespan.
  • These systems operate seamlessly during grid outages.

Cons:

  • Higher upfront cost.
  • Systems have limited power capacity.

Which is Most Cost-Effective?

The exact amount you’ll pay for backup power depends on your home’s size and energy needs. According to HomeAdvisor, the typical price range for a generator system is $1,413-$7,594. Most of these generators are powerful enough to run a typical home during an outage.

By comparison, solar battery backup systems start at around $9,000, not including installation costs. If you’re budgeting for a battery backup system, you can expect to spend between $15,000 and $20,000, including batteries, installation, and other equipment. Fortunately, incentives and rebates can help you access a solar battery backup system at a net cost of about $0 for qualifying homeowners.

Don’t let the upfront price deter you, though. Financing programs are available for qualifying applicants, and battery backup power generates long-term savings that generators don’t. When you purchase a generator, you need to buy fuel, perform monthly and annual maintenance, and replace the generator at the end of its lifespan.

On the other hand, battery backup systems pair with solar energy systems to create a renewable power source. Over time, this can save you thousands of dollars on your electric bill.

Installing a battery backup system may also allow you to access federal and state tax incentives or participate in the SGIP Equity Resiliency program – which we’ll discuss more below.

Solar Battery Backup vs. Gas Generator: Which Option is Best for Me? 

Now that you have the background on each option, which is right for you? Here’s our recommendation:

Buy a Standby Backup Generator if…

A standby backup generator is an ideal solution if you only want a system that can provide emergency power and you have no intention of installing solar panels in the future. If your home has an existing natural gas line, installing a standby generator may be relatively simple.

Buy Solar Battery Backup if…

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

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

Limited-Time Rebates for Battery Backup

solar battery installed

Solar battery backup systems create energy resiliency, which is something the state of California is very invested in right now. As a result, certain households who install a solar battery backup system may be eligible for a limited-time rebate under the existing equity resilience Self-Generation Incentive Program (SGIP) allocation.

This program benefits those living in a fire zone who are also on a Medical Baseline Rate Program. Funds are going fast, but the program funds 80-100% of total project costs if you qualify.

There are also rebates available for those in a fire zone who are not on Medical Baseline. Additionally, officials expect one last rebate bucket for battery customers not in a fire zone or on Medical Baseline. This rebate offer will cover about 10-15% of project costs.

Thinking of Getting a Solar Battery Backup? We Can Help!

Now is an excellent time to invest in a solar battery backup system for your home, and Sandbar Solar is here to help. Our team has over 15 years of experience designing battery systems and can install new battery systems or retrofit existing solar panel systems for a battery backup.

We service homes and businesses across the San Francisco Bay Area and Central Coast.

Contact us today to learn more about our services or take the first step toward your battery backup system.

 

About the Author

Tim has worked in the solar industry since 2008. He has a Master's Degree in Energy Resources Engineering from Stanford University. His years of experience include working on solar energy projects for both homes and commercial properties. Tim enjoys sharing his knowledge of this evolving industry and making a difference in his community.