Should You Get A Tesla Powerwall Or Generator?

Should You Get A Tesla Powerwall Or Generator?

Generators have been the only source of backup power for homes in the residential market, but with the invention of the Tesla Powerwall, you are given a choice for the first time. Knowing which one will work for your home is crucial to keeping the lights on and providing electricity when you desperately need it.

You should get a Tesla Powerwall if you already have an existing solar system attached to your home, can afford the initial high investment cost, and are environmentally conscious. You should get a generator if you have infrequent power outages and are not looking to invest a high amount into your backup power source.

If this is your first time purchasing a backup power source for your home, it’s vital you understand the differences between the two and which will work best for your unique situation. Keep reading to find out the essential info that will keep your home running in an emergency.

What’s The Difference Between A Powerwall And Generator?

The major difference between the Powerwall and generator is that the generator requires a fuel source, but the Powerwall can run directly from the grid or a solar system. But there are other key differences you will want to consider when deciding between the two.

Cost Difference Between The Two

The exact amount of a generator will depend on the company you choose to purchase from and the amount that the company offers for installation. But you can reasonably assume that the generator will cost you around $3000 – $5000 for the generator itself and installation.

This doesn’t include any cost for maintenance or fuel supply, as you will need to keep feeding the generator if you want it to provide power for your home. The most expensive types of generator will run on diesel.

Compare this to the Tesla Powerwall, which just for the battery itself will cost you $7000. And for the necessary gateway and white-glove service of installing it, your total can run up to $11,500.

How To Lower Initial Costs For The Powerwall

Keep in mind that when you are purchasing the Powerwall, there is a federal tax credit that will give you 26% off your total price. This equates to around $2990 and lowers the total amount to $8510.

Tesla will also decrease their gateway and installation costs if you have more Powerwall battery packs that you are attaching to your home by $500.

Even some states, like California, are offering rebates for battery installs up to $3375. Vermont is another state offering rebates up to $10500. All of these rebates combined could lower your total price by a total of 50%.

Operation and Maintenance Differences

As mentioned above, the generator has additional costs you will incur the more you use it. Because it runs on a fuel source, you will need to replenish any lost fuel for running your generator.

Whatever fuel your generator uses, you will need to price out how much fuel the generator consumes each time it runs and then run numbers on the cost of the fuel source to see the long term costs of using a generator..

Diesel fueled generators are the most efficient for running an entire home and have the most upfront costs.

Generators are generally very loud when they are running, and the noise can be noticeable from even inside the home. This is often a complaint from users but doesn’t affect the actual functionality of the unit.

On the other hand, the Tesla Powerwall is significantly quieter when running and doesn’t require a fuel source to maintain.

If you hook your Tesla Powerwall up to the grid, you will see an increase in price for utility bills, and this is an extra expense that needs to be considered. This is why the Powerwall makes the most sense when connected to an existing Solar System

Power Output Of Both Options

Buying a backup power source for your home will require knowing exactly how much of your home you will want to power.

You can choose to power the entire home in an emergency so that you won’t be able to tell the difference between the grid being out or your backup power source is on. You will need to keep in mind that if this is your goal, your initial costs will be much higher and might even require multiple Powerwalls.

Or, you could choose to only power the essential appliances, like your fridge, so that you can continue to have what you need but nothing extra.

One Tesla Powerwall can store up to 14 kilowatts an hour, of which 13.5kWh are usable, which is about half of what the average home uses when powering all electricity.

So if your goal is to completely replace your power from your backup source, you will need to purchase multiple Powerwall batteries and have them connected at different points along your home.

As stated above, when you do purchase multiple batteries from Tesla, you actually get a discount on the gateway and installation fees.

There are generators that will power your entire home if the grid ever gets cut off, but these permanent units can have a price tag of up to $15000 for the unit and installation.

People will usually opt for a more realistic option like a portable generator that can still provide the absolute essentials if the power goes out.  You can also have the option to turn on and off these generators as you see fit.

How Multiple Powerwalls Work Together

Because you can have multiple Powerwalls attached to your home to create an entire system of backup power, it’s important to know exactly what you will get with the following amount of units:

  • Single
  • Double
  • Triple

You can connect the multiple units together side-by-side on the wall or on the floor, but you also have the option to connect them front-to-back (up to 3 deep).

You will need to make sure when connecting multiple units side-by-side you will want to leave enough space on each side for electrical connections and proper ventilation.

If you are connecting front-to-back, then the units will need to be floor mounted and must be stacked to an adjacent wall. You will also need a certified Tesla technician to come out and install the unit using the Powerwall Stack Kit Hardware.

You can connect more than three units but will need to be in separate stacks of three, and each stack will need to be attached to a wall. You can install the units either indoors or outdoors, but you will want to avoid direct sunlight or exposure to extreme temps.

All options will power the following:

  • Lights
  • Electrical outlets
  • 120v small appliances

If you connect two Powerwalls, you can add these additional large appliances:

  • 1x Compatible central air conditioner
  • 1x Electrical range/stove/oven
  • 1x Compatible well pump
  • 1x Tesla EV charging

If you connect three Powerwalls, than you can add expect to power the following:

  • 2x Compatible central air conditioners
  • 1x Electrical range/stove/oven
  • 1x Compatible well pump
  • 1x Tesla/non-Tesla EV charging
  • 1x Electric dryer
  • 1x Electric water heater
  • 1x Pool equipment

Different Options For Generators

There are several types of generators you can consider compared to the Powerwall that only has one company manufacturing and producing one type of battery.

Portable Generators Good For Suburban Homes

As the name suggests, the portable generator can be used at various locations in your home or would be the type you purchase if you were moving homes.

When using a portable generator, it will be fairly loud and will need to be put outside because it produces harmful emissions when in use.

Because of this flexibility, it is often the preferred option for suburban homes where you might need to store away the generator when not in use.

This portability does make it susceptible to theft as it will be easy for others to take your generator if you are away working. It is generally recommended to come up with a secure way to lock up your generator or to put in security measures that can help if someone does steal it.

This type of generator can be used to power any of the following:

  • AC
  • Furnace
  • Refrigerator
  • Emergency lights

Permanent Generators For Frequent Outages

If you have the space around your home to install a permanently fixed generator and you are the victim of frequent power outages, this will make more sense for your home.

This type of generator has a higher initial cost attached, but that’s because it will have more power output and generate more electricity for your home in an outage. This option does require a transfer switch and inverter.

You will need a licensed professional in order to install this type of generator. Still, there is a possibility of installing a battery bank to the generator so that if the fuel source runs out, you have another available powering option for longer outages.

Solar Generator For The Environmentally Conscious

Even though the Powerwall is a much better option in terms of long-term backup solar power, there are generators that have this functionality as well.

You have an option for a single panel or multi-panel solar generators that attach either to the roof of your home or mounted on the ground.

This generator produces DC electricity and can only be used to power appliances in your home that run on DC electricity. But you do have an option to add an AC inverter in order to expand the functionality of your solar generator.

There is also the possibility of adding a battery power bank for even more reliability. Still, you will need to maintain the bank more frequently and will also need to be replaced about every eight to ten years.

The solar generator can have a high initial cost if you are looking to power major appliances in your home that will require twin panels. They should be installed by a professional electrician. Although, there are some DIY methods you can use if you have a background in the field.

Wind Generator For Rural Communities

Wind turbines can be used in rural areas where the wind speed is at least 4 miles a second. You will need to consult with a local weather professional or do some personal testing to determine if you live within the proper zoning and weather patterns.

Because wind itself is unreliable, you will need to attach a battery bank to the wind turbine and an inverter so that wind your turbine produces power, it can be stored in the bank.

You could even feed power back into the grid through a reverse meter but make sure everything is installed by a licensed professional. A turbine can be used for all essential power sources in your home, but it will require regular maintenance.

Can The Tesla Powerwall Be Used Offgrid?

The ability to connect your Tesla Powerwall to an existing solar system means the Powerwall can be used offgrid, but you will need to make sure you live in an area that receives plenty of sunlight.

The way it works is that as the sun begins to hit your solar system it begins charging the Powerwall. This is because the solar panels will produce more electricity than the home needs, so all the excess power begins to store inside the Powerwall.

When the sun starts to set, and your solar system is no longer receiving its rays, the Powerwall takes over as the main source of power for your home. Or when the grid goes down, and you don’t have any other source of power for your home.

If you are looking to replace all the appliances and electricity in your home, you will need to consider purchasing multiple Powerwalls attached alongside the outside of your home. These will produce enough power, together, to make it a seamless transition between a power outage and your Powerwall.

Considerations To Make Before Buying

Now that you understand the differences between the two, you will want to decide why you might need one or the other and in which situations they would perform best.

Where Do You Live?

Are you located in a place where the power frequently goes out due to natural forces? If the following threatens your everyday life, you will want to consider purchasing a larger power source.

  • Hurricanes
  • Tornadoes
  • Earthquakes
  • Blizzards
  • Severe Thunderstorms

If these problems persist where you live then, it won’t make sense to purchase a smaller backup power source because it will significantly hamper how you live every day, especially in these times when we are forced to spend more time indoors.

But if there is only one bad storm every year that you know always knocks out your power, you don’t need to put a large investment into powering your home during this time because you will know it is only temporary.

What Are The Warranties For Each?

The Tesla Powerwall has a 10-year warranty attached that guarantees up to 70% battery usage at that time. And consider as well that this means you should be able to continually run your Powerwall every day to power your home and still reach these numbers.

This is significantly different from a generator, which should only be running if there is an actual outage and you need a backup power source.

A generator warranty will depend on the brand and service you are going with, so you will need to shop around in order to identify the differences.

Most generators have a warranty of around 3-5 years for any factory defects but will not honor that warranty if there are any other kinds of issues. There really isn’t a comparison here as the Powerwall offers a much better warranty if there are ever any issues.

So although the cost of the generator might be initially lower, it might still become more expensive if you have to purchase two generators at the same time you purchase only one Powerwall.

Are You Considering Environmental Costs?

Because generators involve a fuel source like gas, they are constantly eating up the world’s resources every time you need to turn it on. This has a negative effect on our environment, and the cost of this is exponential.

Compare that to the Powerwall who could run on clean energy if hooked up to a solar system, and again, there is no real comparison.

Even if you are connecting your Powerwall to the grid, this will still ultimately have a lower environmental cost than a generator because it lacks the need for a constant fuel source.

And if you want to power your entire home in the case of an outage, the generator will cause much more damage to our environment than the Powerwall will.

Even if you aren’t worried so much about the environment yourself, if you think about your neighbors or your kids or other family members, you may want to consider the negative impact a generator will have.

Savings In The Long Term

If both a Powerwall and generator are connected to the grid and are being used in the exact same way, then the generator will almost always incur fewer costs.

This is because the Powerwall actually requires more charge from the grid than traditional power sources and will ultimately raise your utility bills.

But because of the versatility of the Powerwall, the lack of a fuel source, and the ability to monitor your usage through an app on your phone, the Powerwall is more flexible to save you money in the long term than a generator.

That’s not to mention that if you have a pre-existing solar system on your home, the savings could be thousands in the long-term on energy bills. Using the power of the sun to charge your battery combined with ever-increasing utility rates is how you will end up saving thousands.

Can You Use Both For Your Home?

At a certain point, the Powerwall may be depleted of its backup power source if you are using it to power your home over a long period. Especially if the grid is down for weeks or even months.

Luckily, you can connect your Powerwall with your generator to create a two-device system that can keep your home running for a longer period.

When you have this system connected, the Powerwall is the first backup power source to start working for your home. After the Powerwall begins to deplete all of its power, your generator should automatically turn on at that point, providing seamless backup power to your home.

If you have a solar system already installed, this can work perfectly to power your home for as long as you have sunlight and a fuel source for your generator.

All you need to do is manually flip the transfer switch on your Powerwall so that it begins to recharge using the solar system while the generator is working.

Once the Powerwall has regenerated its power, you can manually switch the system back and start powering your home using the Powerwall, and the generator will turn off.

Repeat the process if the Powerwall goes out again, and your home will be consistently taken care of in an emergency for an indefinite amount of time. But again, keep in mind that your generator will be eating up fuel, so unless you have a large backstock, you will need to find a way to get supplies during inclement weather.

Powerwall and Generator Comparison

There are pros and cons to each, as we have outlined above, so to make the comparison easy for you, here are the pros and cons of each.

Powerwall Pros

  • Very quiet when running
  • When combined with solar provides a renewable energy source
  • Has significant Federal Tax Credits
  • Can combine federal with state and local incentive rebates
  • No extra fuel source needed
  • Can manage directly through an app
  • Can provide 24/7 outage protection
  • 10-year warranty with 70% usage guaranteed
  • Sleek design shows no wires or hot vents
  • Can combine with multiple Powerwalls
  • Water Resistant and made for all weather conditions
  • Can save thousands long-term in energy bills
  • Better for the environment

Powerwall Cons

  • Very high initial cost compared to generators
  • If connected to the grid has limited power capacity
  • Needs pre-existing solar system to operate at full efficiency

Generator Pros

  • Significantly less expensive for the unit
  • Less expensive for the installation
  • Have multiple options from different companies
  • Different types of generators are available
  • Reliable as long as there is a fuel source

Generator Cons

  • Requires a fuel source like gas or diesel
  • Bad for the environment
  • No flexibility in performance
  • Does not recharge from a clean energy source
  • Warranty is short and usually only covers factor defects
  • Can be dangerous around children or pets

How To Know Which Option Is Right For You

If you don’t have an existing solar system in place on your home, it won’t be as cost-efficient to have a Tesla Powerwall over a generator. Even if you can lower the initial cost by using several incentives and the federal tax credit, it still might cost more in the long-term on your electric bills.

Generators are much more helpful for those who are only looking to have a backup power source in case of a real emergency. Especially if you only need to power major appliances to keep your food from spoiling or keep your central A/C system running.

On the other hand, if you are more concerned about the effect of your usage on the environment and you can afford the initial high cost, then going with the Tesla Powerwall is more appropriate for your situation.

This is because the Powerwall can run your home 24/7 as long as it’s charged, which will help incredibly with your long-term electric bills if you are able to connect it to an existing solar system.

The Powerwall can still provide savings if connected to the grid by constantly alternating between a fully charged Powerwall and your grid system. Using this system efficiently during peak usage times will have a significant effect on your energy bills.

You also need to keep in mind the warranty when purchasing a new backup power source and how often your grid will go out throughout the year.

The 10-year warranty of the Tesla Powerwall is impressive compared to generators. Still, if you only have to use the generator once a year, then the initial cost of the Powerwall won’t bring you as much savings.


The Tesla Powerwall is one of the few battery backup power sources available for the residential market, and your options are limited if you want to hook a source to your existing solar system. But competition within the generator market can give you plenty of options that fit your unique situation and home setup. Use the information outlined below to make informed decisions in the case of a real power outage so that your family can remain safe in an emergency.

Solar Discounts:


The articles here on are created by Greg, a Tesla vehicle and Tesla solar expert with nearly half a decade of hands-on experience. The information on this site is fact-checked and tested in-person to ensure the best possible level of accuracy.

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