Key takeaways:
- Home batteries are becoming more common in the greater Nashville area.
- If you’re looking into getting a backup power solution for your home, you should compare generators and home batteries.
- In this blog, we break down the differences between the two in terms of capacity, installation, costs, and more.
Generator or backup battery: There is more than one way to keep essential appliances and equipment powered during outages.
As battery technology becomes more effective and affordable, many Nashville-area homeowners wonder which backup power option is best for them.
We’re here to compare both, go over a few common use cases, and answer some common questions on generator installations and home batteries to help you figure out which one would be best for you.
Capacity: What Can You Power With a Generator or Home Battery?
A generator’s capacity is calculated in watts. This number tells you how much power the generator can deliver at any given time, provided that it’s powered by fuel.
- Capacity typically ranges from 5,000 to 7,000 watts for portable models, and 10,000 to 14,000 watts for standby models. However, you can find larger standby generators with 18,000 watts to more than 20,000 watts of capacity.
- Home battery ratings are expressed in kilowatt-hours (kWh). One kilowatt-hour equals 1,000 watts of power delivered over one hour.
- Backup batteries typically range from 10,000 to 13,500 kWh. However, there are modular solutions like the Tesla Powerwall that let you increase the system’s capacity with expansion packs.
Short-term, a home battery can be comparable to a standby generator and simultaneously power a comparable load. However, the battery will eventually get depleted while the generator will keep running as long as fuel is available.
The Installation Process: Is a Battery or Generator Easier to Install?
A portable generator would be the easiest backup power solution to install. If you’re thinking about a home battery or a standby generator, both installations are similar in terms of how much work is required.
Both systems should be installed by a licensed electrician. They require proper wiring to be connected to your main electric panel, as well as an automated transfer switch. The electrician you work with will need to pull the relevant permits and should follow NEC and local building codes.
A home battery system has a simpler installation process. Your installer will mount the battery, wire it to an inverter, and connect it to your panel. Depending on your setup, they will also connect it to the grid or to your solar panels if applicable.
A portable generator is easier to install because it uses its own fuel tank. An electrician will safely wire the generator to send power to your main panel and power essential circuits, and add a transfer switch or interlock kit.
This process becomes more complex with larger standby generators. Your installer will wire the generator to your panel, but they’ll also need to connect fuel to the generator. This can entail installing a propane tank on your property or connecting a gas line to the generator for a natural gas setup.
You’ll get a better idea of the exact steps required and the scope of the work after talking to an installer about your project since details can vary.
Cost: Is a Home Battery or Generator More Affordable?
If you look at upfront costs, generators tend to be more affordable:
- A portable generator with smaller capacity (5,000 to 7,000 watts) is usually the cheapest upfront in terms of upfront costs.
- Next, you’ll find most standby generators, up to 14,000 watts.
- Home batteries tend to cost more compared to standby generators, but the price is comparable to larger whole-home standby generators with a capacity of 18,000 watts or more.
However, your long-term costs will usually be much lower with a home battery system. Here’s why:
- You’re not paying for fuel with a battery system. You’re either storing electricity from the grid or the electricity your solar panels produce.
- If you take advantage of time-of-use rates, you can keep your home battery full at a low price.
- You also have to consider that electricity rates tend to be more predictable compared to some fuels like the gasoline you would use for a portable generator.
- You’re also saving on maintenance. Because home batteries don’t have moving parts or a starting motor, they’re a lot cheaper to maintain over the years.
A home battery can also help reduce your energy bills if you replenish it during off-peak hours and run your appliances from the battery when energy rates go up during the afternoon. These savings can add up over time and help offset the initial investment.
Home Battery Vs. Generators: A Comparison
A generator might be your best option for extended outages and large electrical loads, while a home battery is a quiet backup solution that can power essential loads.
|
Feature
|
Portable Generator
|
Standby Generator
|
Home Backup Battery
|
| Primary power source | Gasoline, propane, or dual fuel | Natural gas or propane |
Stored electricity from the grid or solar panels
|
| Typical power capability | Often 5,000 to 7,000 watts | Often 10,000 to 14,000 watts, larger systems can exceed 20,000 watts |
Varies by system, a Tesla Powerwall 3, for example, stores 13.5 kWh and can provide up to 11.5 kW of continuous power per unit
|
| How long it can run | Until its fuel tank is empty | As long as fuel is available through a natural-gas connection or propane supply | Until stored energy is depleted, solar may recharge it during suitable daylight conditions |
| Best for | Budget-friendly essential backup during occasional outages | Automatic, long-duration backup for larger loads and more of the home | Quiet backup, short-to-moderate outages, solar storage, and energy-cost management |
| Installation | Can be used with extension cords, a transfer switch or interlock kit improves safety and convenience | Permanent installation with transfer switch, electrical work, and fuel connection | Permanent installation with battery, inverter, electrical-panel connection, and backup-control equipment |
| Automatic operation | No, homeowner must start and connect it | Yes, starts automatically when utility power fails | Yes, typically switches to battery backup automatically |
| Noise level | Loudest option | Noticeable engine noise while operating | Very quiet; no combustion engine |
| Emissions | Produces exhaust while running | Produces exhaust while running | No on-site exhaust emissions during operation |
| Routine maintenance | Regular oil, fuel, and engine maintenance | Scheduled engine, battery, fuel-system, and exercise-cycle maintenance | Generally low maintenance, no engine oil changes or fuel storage |
| Upfront cost | Usually the lowest-cost option | Moderate to high, depending on size, fuel work, and electrical upgrades | Often higher upfront cost, particularly for whole-home backup or multiple batteries |
| Long-term operating cost | Ongoing fuel purchases and maintenance | Ongoing fuel purchases and maintenance | Can have low routine operating costs, may store solar energy or lower-cost off-peak electricity |
chedule a Backup Power Consultation With Airstream Services HVAC, Electrical & Plumbing
Not sure if a generator or home battery is best for your Nashville home? Airstream Services HVAC, Electrical & Plumbing has been serving Middle Tennessee since 2012.
As a licensed electrician and generator installer, we specialize in safe and code-compliant backup power system installations. Before we recommend a system, we do a home assessment and calculate the total electrical load you want to backup. We can then discuss your options and help you figure out whether a generator or home battery would be best.
Schedule your consultation today or give us a call at 616-216-5979 if you have any questions.
FAQ
Is a generator or home battery better for a power outage?
A generator is often better for longer outages because it can keep running as long as fuel is available. A home battery is ideal for quiet, automatic backup during short outages and may recharge from solar panels. The best option depends on your power needs, budget, and outage risk.
Can a home battery run my entire house?
It depends on the battery’s stored energy capacity and power-output rating, as well as the appliances you want to run. A battery may support essentials such as lights, refrigeration, internet, and selected outlets, but high-demand systems like central HVAC, electric water heaters, and EV chargers may require multiple batteries or load management.
Are home batteries more expensive than generators?
Portable generators usually have the lowest upfront cost. Standby generators are typically less expensive than a comparable whole-home battery system, although pricing depends on capacity, installation requirements, fuel connections, and electrical upgrades. Home batteries may have lower ongoing costs because they do not require fuel or engine maintenance.
Do generators or home batteries require more maintenance?
Generators generally require more ongoing maintenance because they have engines, fuel systems, and moving parts. Portable generators need regular oil changes, fuel checks, and periodic test runs, while standby generators typically need scheduled inspections and exercise cycles. Home batteries have no engine or fuel supply to maintain, so they usually require far less routine upkeep, though an installer should periodically inspect the system, connections, and software.
