Battery backup vs. generator: which is right for your home?

The huge winter storm over the last week affected millions Americans. We had 18” of snow at our house, and many people across the country got hit with a combination of snow, sleet, and ice — a recipe almost ideally designed to knock out power. So, we thought it would be a good time to look at home backup power options. 

And stepping back from just this storm, power outages are lasting longer than ever, up 38% from 2023 to 2024 alone, according to the U.S. Census Bureau. For many homeowners, that means rethinking how to keep your essentials running when the grid goes down.

Home battery systems and backup generators are two of the most common solutions. Both can keep lights, heating, and Wi-Fi online, but they work in very different ways. This guide breaks down how each system operates, what they cost to install and maintain, and how pairing solar with battery storage can create a cleaner, quieter, and more resilient source of backup power.

How home batteries and generators work

When the power goes out, backup systems help keep electricity flowing in very different ways. Battery systems store electricity from either the grid or solar — “solar-plus-storage” is becoming a more popular way to store the renewable power from rooftop solar to use when you need it (to reduce your grid dependence, and to have a backup source of energy). Fuel generators create power on demand by burning natural gas, propane, or diesel. Batteries store power quietly and automatically, while generators create it on demand by burning fuel.

What is a battery backup system?

A home battery system stores electricity from solar panels or directly from the grid. When the grid goes down, your system automatically switches over in just a few seconds, keeping your electricity running.

Inside the battery, a built-in inverter converts stored direct current (DC) into the alternating current (AC) your home uses. The system cycles between charging and discharging as needed, similar to how your cellphone battery works, but on a much larger scale. Each battery has a usable capacity, which is the portion of stored energy that can actually power your home during an outage. Once backup mode kicks in, you draw from that usable capacity to run your essential items until the grid returns.

Modern batteries operate silently and have no exhaust, so you can install them indoors or in a garage without ventilation concerns. When paired with solar, they recharge from the sun during the day and supply a steady source of solar power during outages whenever you need it. They can even provide energy to your home during times when electricity is expensive, cutting your electric bill significantly.

Battery systems are built to last for ten years or more and can keep essential appliances running for several hours at a time, depending on the amount of energy you use. A single unit can typically power lighting, refrigeration, internet, mobile charging, and a few small appliances. Homes that have large energy loads, such as central air conditioning or well pumps, may choose to install more battery capacity for longer run times.

What is a solar-plus-storage?

Solar-plus-storage refers to a permanent backup solution consisting of solar panels, a hybrid inverter, and a battery engineered to operate together during outages. 

It works much like a solar-powered battery backup setup:

• Your solar panels produce electricity during the day.
• A hybrid inverter routes that energy to your home and charges the generator’s battery.
• When the grid goes down, the inverter automatically isolates your home (also commonly known as islanding) and pulls stored energy from the battery.
• Solar panels can recharge the battery while the system powers essential loads.

Because the battery can recharge from solar during the day, solar-plus-storage can provide multi-day backup — something standalone batteries and fuel generators can potentially have trouble with. These systems operate silently, require no fuel, and continue powering loads as long as sunlight is available to recharge the battery. Batteries in solar-plus-storage systems are typically sized to meet overnight power needs, with solar replenishing them the next day.

What is a backup generator?

Backup generators use natural gas, propane, or diesel to create power. Standby models rely on an automatic transfer switch, which senses an outage, disconnects your home from the grid, and sends generator power to your panel. Portable generators are a smaller, manual option that you start yourself and connect to selected circuits or appliances — you can think of them like a lawn mower engine that generates electricity instead of spinning mower blades (they’re often just as loud).

Generators can run for long periods as long as they have fuel, although they need regular service to stay reliable. With proper maintenance, a standby unit often lasts 10 to 20 years. Power output varies by size, but residential models can handle larger loads such as air conditioning, sump pumps, or well pumps, while portable units are better suited for basics like lighting, refrigeration, and internet equipment.

Battery backup vs generator: main differences

Both systems can keep your home powered when the grid goes down, but they do it in very different ways. The table below highlights the key differences that matter the most for homeowners — how they’re powered, what they cost, and how they fit into everyday home life.

System	What It Is	Typical Fuel / Power Source	Automatic?	Powers Whole Home?	Best Use Case
Home Backup Battery	A permanently installed lithium battery connected to your electrical panel that stores energy for outages	Grid electricity (unless paired with solar)	✅ Yes	⚠️ Sometimes (depends on size; most power only essential circuits)	Clean, quiet backup for essentials without installing solar
Solar-Plus-Storage (Solar panels + home battery)	A full home energy system pairing rooftop solar with a battery that recharges from sunlight during outages	Solar energy + grid as needed	✅ Yes	✅ Yes (when properly sized)	Multi-day outage protection, long-term energy savings, maximum resilience
Whole-Home Generator	A permanent combustion generator wired into your home’s panel to create power during outages	Natural gas, propane, or diesel

Battery backup vs generator cost comparison

When you’re comparing systems, it helps to look beyond the sticker price. Batteries and fuel generators differ not only in upfront costs but also in how much they cost to operate and maintain over time. Incentives for clean energy can narrow the gap even more, especially when you pair a battery with solar to install a full solar-plus-storage system.

Upfront costs

According to the National Renewable Energy Laboratory’s 2024 Annual Technology Baseline, a typical residential battery system (around 12.5 kWh capacity) costs about $15,000 to $18,000 installed, or roughly $1,200–$1,400 per kWh. Larger systems designed for full-home backup can reach $20,000 or more. Prices vary by brand, chemistry, and installation complexity. Installation often includes permit and inspection fees, which usually range from $100-$500, depending on your location.

A full solar-plus-storage system, which includes rooftop solar, hybrid inverters, and battery storage, can range from $25,000–$40,000 before incentives, depending on the size of the solar array and storage capacity. However, because these systems generate electricity year-round — not just during outages — they offer both backup power and utility bill savings.

Standby gas generators usually run $3,000 to $10,000 installed, depending on size, brand, and whether you already have a natural gas line. Installation costs can rise if trenching or propane setup is needed, but overall, generators still carry a lower initial price tag than batteries.

Residential Clean Energy Credit

The Residential Clean Energy Credit still applies to home batteries, provided the battery is at least 3 kWh and permanently installed — and can cover 30% of the battery’s, including equipment, labor, wiring, and permitting, for new installations through 2032. Any unused credit can roll forward to future tax years, and some states offer additional rebates or incentive programs.

A quick note, with the One Big Beautiful Bill Act (OBBBA) (again, we didn’t name it) these incentives are changing pretty quickly. So, make sure you check with your installer to understand the latest.

Ongoing costs

Batteries have almost no ongoing expenses because they don’t use fuel or have moving parts that wear out. Warranties typically range from 10 to 15 years across major brands, and upkeep is usually limited to software updates and occasional system checks.

Solar-plus-storage also has minimal ongoing costs because the system uses free sunlight and requires no fuel or mechanical maintenance beyond occasional monitoring and software updates.

The fuel that generators require, on the other hand, can add $300 to $800 per year for typical use, depending on local gas or propane prices and how often the system runs. Routine service, such as oil and filter changes every 100 to 200 hours of operation, adds more over time. 

For homeowners who only face a few outages each year, those costs can add up quickly compared to a battery that simply stays ready and recharges from solar.

Long-term value

Over a 15- to 20-year lifespan, batteries can deliver strong long-term value, especially when paired with solar, because the battery can recharge from sunlight and reduce grid reliance. However, solar-plus-storage has the potential for the highest lifetime savings.

Fuel-based generators can run continuously, but they don’t reduce your energy bills or qualify for clean-energy incentives like solar-based systems do. 

If your goal is reliable, low-maintenance power and long-term savings, solar-plus-storage provides the greatest overall value. But if you don’t have solar and live in an area with long, infrequent outages and need to power large, heavy-load equipment, a standby generator may be the more practical fit.

Here’s a snapshot of what the real numbers look like today:

Category	Home battery	Solar-plus-storage	Generator
Installation	$12,000–$20,000 (before incentives)	$25,000–$40,000 (including both solar panels and home battery storage)	$3,000–$10,000 installed (size and fuel type dependent)
Maintenance	Minimal	Minimal	Moderate to high
Fuel costs	None	None	$300–$800 per year typical
Incentives	30% federal tax credit, plus possible state incentives	30% federal tax credit, plus possible state incentives	Not eligible
Lifetime (years)	10–15	15–25	10–20

Battery cost data sourced from DOE & NREL 2025 residential storage benchmarks

Home battery vs generator pros and cons 

Both batteries and generators can keep your home powered when the grid goes out, but they fit into daily life in different ways. Let’s go to the pros and cons!

Battery backup: Pros

A home battery provides quiet, clean, automatic backup power. When the grid fails, it switches on within seconds to keep your lights, internet, and fridge running. It doesn’t burn fuel or release fumes, and most systems last a decade or more with minimal upkeep.

If you have solar panels, the battery can recharge from the sun during the day and run your essentials at night. That same setup can also lower electric bills by storing power for use during peak hours. Many homeowners choose batteries for the comfort of knowing they have clean, silent backup that works on its own.

Battery backup: Cons

Batteries cost more upfront than generators, even after tax credits, and their run time depends on their capacity and how much power you use. One unit will usually cover essentials for several hours or a day. Homes in very cold climates may require climate-controlled installation to maintain performance and longevity.

Solar-plus-storage: Pros

A solar-plus-storage system — solar panels + hybrid inverter + battery storage — offers the most sustainable, lowest-maintenance form of backup power.

Pros include:

• Unlimited recharging whenever there’s sunlight
• Silent operation and zero on-site emissions
• Integrated home backup without fuel, fumes, or noise
• Year-round savings, since the system generates and stores your daily electricity
• Highest long-term value, because it replaces grid electricity rather than supplementing it

Because the battery recharges from your solar panels during the day, solar-plus-storage can sustain multi-day outages more effectively than standalone batteries or fuel generators.

Solar-plus-storage: Cons 

While solar-plus-storage has a ton of pros, there are some things to consider.

• Higher upfront cost, since the system includes both solar panels and battery storage
• Requires roof space and sunlight exposure
• Installation is more complex than a generator
• Backup duration depends on both the size of the solar array and battery capacity

For homeowners with limited roof area — or heavy energy loads like electric heating — solar alone may not fully power the home during long outages without additional battery capacity.

Fuel generators: Pros

Generators are designed for longer outages and heavier power use. They can handle large appliances and keep running as long as there’s fuel. Installation is usually quicker and less complex than a solar-plus-battery setup, and you can choose between natural gas, propane, or diesel.

They are also often the lowest-cost option for homes that need very high surge power or extended whole-home coverage.

Fuel generators: Cons

Generators need regular testing, oil changes, and refueling to stay reliable. Fuel deliveries can be delayed during major storms, and operating costs add up over time. They’re also noisy and produce exhaust, so placement outdoors and away from windows is essential. 

Generators do not integrate directly with solar panels or battery systems without specialized equipment, and they cannot be powered or recharged by solar energy.

Finding your ideal backup power solution

The best backup system for your home depends on your habits, your budget, and how your local power grid performs. A few simple questions can help you find the right fit.

1. How often do you lose power?

If you deal with short, occasional outages, a home battery is usually enough to keep things comfortable. It will run your essentials quietly, recharge from solar, and stay ready without any effort.

If your area experiences long or repeated blackouts, a generator might make sense. It can keep large appliances running for as long as you have fuel. A solar-plus-storage system can also be a great fit for multi-day outages, since the battery can recharge from sunlight during the day. Some homeowners even combine a solar battery for everyday reliability and a small generator for rare, extended outages.

If you’re not sure how much electricity your household typically uses, take a moment to review how total wattage adds up across lighting, appliances, and heating or cooling systems. It’s a good way to understand your home’s true energy needs before sizing a battery or generator.

2. What matters most to you?

If you want quiet, clean energy with little maintenance, a battery or solar-plus-storage system is hard to beat. It runs automatically and helps cut your environmental impact by storing electricity instead of burning fuel. The cost is higher up front, but rebates and lower energy bills can balance that out.

If your goal is dependable power at a lower initial cost, a generator might be right for you. It’s less expensive to install and delivers strong surge power for heavy appliances. The trade-off is that it uses fossil fuels and produces emissions, it is generally pretty loud, and you will spend more on fuel and maintenance over time.

3. What does your home allow?

Batteries are compact and usually installed in a garage, basement, or utility room. They need a clean, dry location with enough wall space for the unit and safe clearance around the wiring and inverter. Most areas require an electrical permit and an inspection, and some also have temperature requirements. Many manufacturers recommend keeping the battery in a space that stays within normal indoor temperature ranges to protect performance.

Solar-plus-storage systems require roof space for solar panels and an indoor or garage location for the inverter and battery. Homes with shaded roofs may be better suited to a battery-only or generator solution.

Generators need outdoor space with ventilation and a safe distance from windows or doors. Most areas require a concrete pad, setback clearance, and a permit for electrical and fuel line work. Cold climates may need propane instead of diesel to avoid fuel thickening.

4. Who should install it?

Backup power is only as reliable as the person who sets it up. Look for a licensed installer with experience in the system you want. Ask them to review your electrical panel, estimate your critical loads, and explain how everything works. A good installer will walk you through warranties, service plans, and future expansion options, whether that means adding more storage or connecting to an EV charger later.

Why solar and storage are the future of home power

Reliable backup matters more than ever as outages last longer and happen without much warning. Solar paired with a home battery gives you a complete energy system that keeps working day and night. Your panels charge the battery during the day, and the stored energy keeps your lights, fridge, and essential devices running at night or during a blackout.

Solar and storage offer clean, quiet power without fuel, exhaust, or ongoing maintenance. Battery costs are steadily declining, and the National Renewable Energy Laboratory projects a 17-30% drop by 2035. New lithium iron phosphate technology also brings longer service life and added safety. These improvements are why more homeowners are choosing solar and storage for resilience, long-term savings, and a more sustainable household.

Solar-plus-storage systems build on this by enabling continuous daytime power production — even during outages — providing the most self-sufficient option available today.

If you are thinking about backup power options, take a moment to look at your energy habits, outage history, and long-term goals. A qualified local solar installer can help you compare systems, size the right setup, and understand what solar and storage can do for your home.

Frequently asked questions

Can a battery backup system power my entire home during an outage?

It depends on the size of the battery and the amount of electricity your home uses. NREL’s 2024 Annual Technology Baseline lists a representative residential battery with approximately 12.5 kWh of usable storage, which is typically sufficient to run essential circuits for several hours before recharging is required. Industry guides show that home batteries can range from 10-16 kWh, so households looking for longer runtimes or whole-home backup often install two or more units to cover larger appliances or extended outages. If you’re trying to size your system, it helps to know how much backup power your home actually needs to stay comfortable during an outage. 

How long can a generator run continuously?

A standby generator can basically run for as long as it has fuel and is maintained properly. Natural gas models can operate for several days since they draw fuel directly from the gas line, although most manufacturers recommend a short cool-down period roughly every 24 hours. Propane systems depend on tank size. A standard 100-gallon tank can typically power a 10 to 20 kW standby generator for 1 to 3 days at half load. Larger tanks provide longer runtimes. Diesel units often have built-in day tanks and can run 12 to 24 hours before refueling. Actual runtime depends on fuel type, load, tank size, and whether routine maintenance checks are followed.

What are the main differences between a battery backup and a generator?

Batteries store electricity and run silently with no on-site emissions. They pair naturally with solar, need very little maintenance, and typically last 10 to 15 years. Upfront costs are higher than a generator, but operating costs are low because they do not use fuel.

Generators make electricity from natural gas, propane, or diesel, so they create exhaust and need regular service. They cost less to install but have ongoing fuel and maintenance expenses, and they generally last 10 to 20 years with proper care. Generators can deliver higher continuous power and will keep running as long as they have fuel.

What are the costs associated with installing and maintaining battery backups versus generators?

Battery systems cost more at the start, but they are inexpensive to live with because they do not use fuel and only need simple check-ins or the occasional software update. Generators are cheaper to install, but the yearly costs add up. They burn fuel and need regular upkeep to stay reliable. Most manufacturers call for oil and filter changes every 100 to 200 hours of use, and a basic service visit usually falls in the $150 to $300 range. Bigger tune-ups can run $300 to $600, depending on the generator and the local company doing the work. 

How do battery backups and generators work during a power outage?

A battery system detects the outage and takes over right away, keeping the circuits you chose during installation running. It will keep supplying power until the battery is depleted, and if the system is paired with solar and a compatible inverter, your panels can continue charging it during the day until the grid comes back. 

A standby generator starts automatically when the power goes out. The transfer switch isolates your home from the grid, and the generator sends electricity to your panel for as long as it has fuel. Natural gas models can run for several days, while propane or diesel units depend on the size of the tank and the load you are using.

Can I integrate a battery backup with solar panels?

Yes. Batteries and hybrid inverters are designed to work with rooftop solar. The battery can charge from your panels and discharge when you need it. This improves self-consumption and supports resilience. Your installer will size the inverter and battery bank to match your array and your backup goals.

Which option is more environmentally friendly: battery backup or generator?

A battery is more environmentally friendly. It creates no emissions during use. A fuel-based generator produces CO₂ and other pollutants.

Photo of snowy house by Biegun Wschodni on Unsplash