How Much Home Battery Backup Do I Need?

As we move into the new age of batteries and away from gas or diesel maintenance hogs, two important questions to ask are: How much battery do I need, and what determines the size of the battery?

How Do I Calculate Wattage For Home Battery Backup?

Battery size is measured in KWh or Kilowatts / per hour. The battery values are thus measured using the metric system. For example, when discussing weight, one(1) Kilogram is 1000 grams, similar to weight one(1) Kilowatt is 1000 watts. Now that you have a refresher on the metric system, it will be easier to understand what a battery of one(1) KWh is capable of using the following example: a battery of 1 KWh or 1000 Wh will be able to run a 1000-watt space heater for 1 hour.

Common Sense

Now, let’s talk statistics. You need to know how long you will need to use battery backup to calculate an accurate battery size estimate. Meaning, how much time does the average power outage take? The average power outage time is measured with a metric called The Customer Average Interruption Duration Index (CAIDI). For Pennsylvania, the average time is 189 minutes if it’s a major weather event and 128 minutes if it is not a major event. Obviously, it takes a bit longer when the weather is really bad because there are more outages, and it takes longer to address them all. Use the CAIDI metric when calculating your battery size to see how much KWH you need to run essential appliances during a normal power outage.

It is also important to know how often an outage happens. Pennsylvania is, unfortunately, not the best state to live in, as the reliability ranking is low. So, how can we best prepare ourselves?

Reasons To Get A Home Battery Backup

There are many reasons to get a home power backup system, but let’s look at some obvious examples. Let’s say you have medical equipment that needs to run 24/7 making a backup a necessity. But what about your refrigerator and freezer? You may have some decent money in a refrigerator or a freezer with all the food you have stored. Before you know it, you are at a thousand dollars, and all that food can go to waste. The average outage is 128 minutes, but if you are unlucky and out for a day your food might go bad. An outage of a day or longer will mean your food will go to waste and you will need to replace the lost contents.

Therefore, based on our 20 years of experience with customer situations, we at Belmont Solar came up with the three most used scenarios.

  • Home Battery Backup For 8 Hours
  • Home Battery Backup For A Day (24 hours)
  • And for power-hungry folks, Two Days Of Home Battery Backup

Choose What Your Home Battery Backup Will power

Ideally, you do not want to break your neck when stumbling out of bed during a stormy night. Lights are essential and most, if not all, households have LEDs which use very little power. If you still use incandescent bulbs, we recommend upgrading to LEDs since they use much less power. A home battery backup will power many LED lights during an outage.

However, home circuitry usually contains appliances not needed in an outage, so we must be strategic when deciding which circuits need to be powered by the battery. Kitchens, hallways, and staircases are good circuits to power up. Internet, TV, and Radio are also essential during a storm so you can stay informed and contact friends and family when needed. It’s very interesting to know that, although your power is out, your internet is more likely to remain on, due to the physical strength of these communication cables.

What About A Home Battery Backup For Heating?

Power outages usually happen in the winter, and depending on your situation, you can or cannot heat the house. If you have all electric heating with no backup, a lengthy power outage will be problematic, which is why we recommend getting wood or propane heating as a backup. If you use oil, natural gas, or propane heating, you are in luck, as most of these heaters require little electric power (a maximum of 1000 watts, depending on the age of your heater).

We at Belmont Solar will analyze your home and advise you on your power usage for heating. We will work with you to determine the best plan of action based on your experience with power outages in your neighborhood.

Do I Need Solar If I Want A Home Battery Backup?

In most cases, a solar system with a battery backup would make sense, since solar will significantly extend your reliance on the battery. Your solar system will charge your battery during the day and you use the charge at night when your system is not generating power. Any power you have used at night will be replaced during the day. However, if solar is not an option, you can choose to go without solar and charge the battery using the grid. A home battery backup is helpful for apartments or if your HOA does not allow solar panels.

The good news is no solar is needed for your battery backup system. However, it does give you more control and less reliance on the grid.

Home Battery Backup Cost

The three most used scenarios, as described above, are;

  • Home Battery Backup For 8 Hours
  • Home Battery Backup For A Day (24 hours)
  • Two Days Of Home Battery Backup

Option 1: Home Battery Backup For 8 Hours

Option 1 will get you through most if not all power outages. You can power lights and communication (Internet, TV, and Radio), charge smart devices, run your refrigerator and freezer, and use medical devices like a CPAP machine, etc. The inverter will keep you updated on your battery status via an app. Option 1 will be the size of a hotel mini fridge. (picture for reference)

Option 2: Home Battery Backup For A Day (24 hours)

Option 2 is a medium-sized battery about the size of a hotel fridge and freezer with all the features of option 1 and more. A medium-size battery backup will get you through most power outages, and depending on the duration of the outage, you can power some electric heating, which is essential in deep winter. Let’s say the outage happens in the middle of the night. You can wait until the following day after coffee and breakfast to start your wood stove or propane heater. Since you have more storage, you can use more appliances, especially if you know the power will return in a few hours. Using the app, you can monitor how much charge is left on your battery and adjust your power usage accordingly.

Option 3: the bigger boat 🙂 

Option 3 is our largest home battery backup. Large homes have more area to light up, sometimes more appliances like refrigerators and freezers, and they usually have double heating systems. More appliances require more power, and double heating systems require twice the power for the fans and controls. You will need a large backup because of the additional power usage.

Option 3 is also intended for people living in remote locations. Most people living in remote areas have experienced long power outages and are prepared with ample wood storage for heating. A large battery backup will help alleviate the pain of an extended power outage.

Your Home Battery Backup

Every scenario is specific to each customer, and the security mindset is an important factor in determining your battery size. We at Belmont Solar specialize in helping you find the right option for you, and we hope this information gives you an excellent base to start our discussion and your journey toward power security. You don’t need to be a prepper to be prepared and help you and your family through the unexpected. Having power makes all the difference.

Let’s talk.

Call us at 717-768-7796 and let our power consultants help you get a good-working and economically balanced power solution. Please note that the pricing in this blog is for home battery backup only. Of course, we always recommend installing a solar system to become more energy-independent. You can use our solar calculator for pricing on a solar system with battery backup. We look forward to hearing from you!