What's the difference between a home battery and a generator?

Batteries and generators can both provide backup electrical power during a power outage. The big difference between them is in their fuel source.

Home generators

A home generator is a fuel-powered backup system that runs on natural gas, propane, gasoline, or diesel. They fall into two main types:

• Whole house generators (also called "home standby generators") are permanent fixtures that kick in automatically if the power goes out.
• Portable generators can be stored away and brought out when there's an outage.

Home battery systems

A home battery backup system doesn't generate power, but stores power from solar panels or the grid. You can use the stored energy to power your home during an outage or during peak periods, when time-of-use rates are highest.

If your battery is connected to solar panels, it can recharge during the day. Or you can recharge your battery from the grid when energy is cheapest.

That makes battery storage better for the environment, and for your wallet – you can use your battery every day to save money on your energy bills. By contrast, generators need to be stored safely and kept maintained and fueled up when not in use.

What's the difference in cost?

Both generators and battery systems can have a high upfront cost. However, there are major differences in how much you'll pay and the long-term financial benefits you'll get from them.

Batteries, for instance, are eligible for a number of incentives that bring down the overall cost, and they can pay for themselves over time through savings on every energy bill. Let's break down the cost and savings potential for each.

Generators can cost anywhere from $200 to $20,000, depending on the type, features, and power output. Purchasing and installing a generator to back up your whole home costs $10K to $20K, on average.

Generators need to be set up safely and properly. Professional installers can place the generator in a safe spot outside the home and ensure that it's correctly connected to a fuel tank or gas line. Whole house generators are the most expensive to install, but even having a portable generator professionally installed costs $1,200, on average.

Lastly, fuel costs add to the overall cost of owning a generator. Fuel costs will vary because some generators can connect to a main gas line while others will require a tank of fuel, like liquid propane or diesel. With any kind of generator, you're locked into some kind of fuel cost for its entire lifespan.

Home battery backup has a higher upfront cost. The average cost of a home battery system runs from $18K to $23K, including installation. That cost can be higher if you're installing solar panels with your battery, but you get the extra benefits of solar savings and the ability to recharge your battery during an outage.

Unlike generators, home battery systems pay for themselves over their lifetime. You can also take advantage of incentives to help lower the upfront cost. Thanks to the Inflation Reduction Act (IRA) and state rebates, battery storage is more affordable than ever. For example, under the IRA, you can claim 30% of the cost of the battery as a federal tax investment credit.

How long can generators and batteries back up a home?

Most batteries have a continuous power rating of 5 to 8 kilowatts, which is enough to power your most important appliances for a day or two – or longer if you have solar panels to recharge your battery. Homeowners who install a home battery recognize that they won't be able to power their entire home, but they can customize their system to power their critical appliances, like their refrigerator, lights, garage door, and outlets for charging mobile devices.

Generators, on the other hand, will last as long as they have fuel. They can run continuously for up to three weeks if necessary.

Is battery backup better than a generator?

By almost every measure, home batteries are better than generators. Here are a few reasons why:

• No ongoing costs – Batteries charge from solar panels or the grid, so they don't need fuel and require very little ongoing maintenance. With a generator, fuel costs can be considerable, especially if you pay to have fuel delivered. And generators need to be tested every few months.
• Better for the planet – Batteries don't use fossil fuels, so they don't emit carbon dioxide or other greenhouse gasses.
• No loud noises – Because batteries have no moving parts, they're much quieter than generators. You won't even hear them running.
• Health advantages – Generators can cause carbon monoxide poisoning and other accidents if they're not used or installed correctly. Batteries don't have that risk, so you won't need to worry about affecting the air quality in or around your home.
• Savings – You can use your battery system every day to save money on your energy bills. Using energy from your battery when electricity costs are highest helps you avoid peak charges. Your savings will be even greater if you pair your battery system with solar panels because you can store the free solar electricity to when rates are highest.

If you're interested in learning more about a home battery, Haven is here to help. We know installing battery storage can be a big decision, so we take care of every step in the process – from choosing your battery to system design, permitting, installation, and ongoing energy management. Get a free quote today.