Generator or battery backup? Choosing the right home backup power solution

Power outages are uncommon, but severe weather and other unexpected events can happen. If you’re considering a backup power solution for your home, there are more options available today than ever before.

While generators have long been the traditional choice, battery energy storage systems (BESS) are becoming an increasingly popular alternative, offering quiet, automatic backup power and additional benefits beyond outages.

Because Hydro Ottawa does not sell or install these systems, costs and system design will vary depending on your home’s electrical setup, installer and backup power needs. The information below provides a general overview to help you compare your options.

Traditional generators

Generators produce electricity using gasoline, propane or natural gas. Portable models can supply power to selected appliances, while permanently installed standby generators can automatically power much larger portions of your home.

Advantages

• Can provide power for extended outages as long as fuel is available.
• Well suited for homes with higher electrical demands, including larger heating and cooling systems.
• Standby generators can start automatically when the power goes out.

Things to consider

• Require regular maintenance and periodic testing.
• Produce noise and emissions while operating.
• Require access to fuel during prolonged outages. 

Typical cost

Portable generators generally range from $500 to $3,000, with professionally installed transfer equipment typically adding $400 to $1,500.

Whole-home standby generators generally range from $10,000 to $25,000 or more, including installation, fuel connections and required electrical permits.

Battery energy storage systems (BESS)

A battery energy storage system stores electricity for later use. During an outage, it can automatically provide backup power to selected circuits or, depending on system size, much of your home.

Unlike generators, batteries operate silently and produce no emissions during use.

Advantages

• Instant, automatic backup power.
• Quiet operation with minimal maintenance.
• Zero on-site emissions.
• Can be paired with rooftop solar to store excess solar energy for later use.

Things to consider

• Higher upfront investment than many generator options.
• Backup duration depends on battery capacity and how much electricity your household uses during an outage.

Typical cost

A battery system designed to power essential household loads typically ranges from $12,000 to $25,000 installed. Larger systems capable of backing up most or all of a home can range from $25,000 to $45,000 or more.

Beyond backup power

For some homeowners, a battery system can do more than provide backup during an outage. Eligible customers in parts of Kanata and Stittsville can enroll their battery in Hydro Ottawa’s GridFlex program and earn rewards for allowing their battery to help support local grid reliability during occasional periods of peak electricity demand. While backup power remains available when needed, participating batteries can also provide value throughout the year by supporting a more flexible and resilient electricity grid.

Additionally, homeowners looking to install battery storage (when paired with solar panels) can offset their upfront equipment costs by taking advantage of provincial rebate opportunities available through the Home Renovation Savings program. 

Hybrid systems

Some homeowners choose to combine both technologies by pairing a battery with a standby generator.

In this configuration, the battery provides immediate, seamless backup power, while the generator automatically starts only when needed to recharge the battery during longer outages.

Advantages

• Instant backup power.
• Extended operation during prolonged outages.
• Reduced generator run time, resulting in lower fuel consumption and less noise.

Things to consider

• Highest upfront cost.
• More complex installation than either technology alone. 

Typical cost

Integrated battery and generator systems typically range from $20,000 to $40,000 or more, depending on system size and installation requirements.

Which option is right for you?

The best backup power solution depends on your home’s electrical needs, budget and priorities.

A traditional generator may be the right choice if you want long-duration backup power and have significant electrical loads. A battery energy storage system offers quiet, automatic operation with little ongoing maintenance and may provide additional value beyond outages. A hybrid system combines the strengths of both technologies for homeowners seeking maximum flexibility.

Before making a decision, it’s worth speaking with a qualified electrical contractor or installer who can assess your home’s requirements and recommend a solution that’s right for you.