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How Long Can a Solar Battery Power a House?

Solar panels on a house

How Long Will Solar Batteries Power Your Home?

One of the most common drivers for installing batteries in addition to a solar panel system is energy shortage in times of need. When there are power outages to do overuse, inclement weather, or power grid failure, having stored energy in batteries can keep your house running. Additionally, using solar batteries as a method of storage is also helpful in lowering your overall electricity bills and power grid usage. Solar batteries both protect your home from electrical vulnerabilities and provide a level of self-sufficiency.

Can I run my house on a solar battery during a power outage?

During a power outage, you can keep your home running with store electricity. The primary purpose of storing electricity generated from your solar panels is to have a back-up plan when traditional power fails. Depending on the size of your home, your electricity usage, and how much energy you have stored, you can power your home for a decent amount of time until the power grid is up and running again.

How many solar batteries are needed to power a house?

The amount of batteries you’ll need depends on a variety of factors including the size of your home, the amount of electricity you use, and what you hope to get out of your home’s solar panel system. A basic guideline for the average American homeowner who uses their solar panel system to reduce electrical costs and power a home with the standard electrical appliances is between one and three batteries. Keep in mind, this is not suitable for those who wish to live off-grid and power the home almost entirely from self-produced energy. If that is the case, you would look more between eight and twelve batteries.

Factors that impact how long you can power your home with solar batteries

When it comes to powering your home with batteries, a 10 kilowatt hour (kWh) battery can power your home for about 24 hours without any AC or heat running. However, there are a variety of factors that can impact exactly how long you can power home, including battery storage capacity, the output of your solar panel system, and your electrical needs.

Battery Storage Capacity

Battery storage capacity refers to the amount of electricity your batteries are able to hold. This is often measured in kilowatt-hours or kWh. The average battery is about 10 kWh. In a power outage a fully charged 10 kWh battery should allow you to power your home for 24 hours. However, it is important to not entirely drain all the energy of the battery. Keeping a 5%-10% charge on your battery ensures that it remains healthy and has enough energy to start up in the morning.

Solar Panel Output

Solar panel output refers to the amount of energy your panels are able to generate, this depends on both the amount of solar panels you have and the weather in your area, i.e. lots of sun or periodic sun. Your solar panel system paired with batteries essentially creates its own power utility system. Often in times of power outages, your solar system will be turned off, so you’ll rely heavily on the stored energy.

Electrical Needs

In the simplest terms, how long you can power your home depends heavily on how much energy you use day to day. During a power outage it is crucial to prioritize your electrical use in running the multiple appliances that are necessary versus those that aren’t, for example your refrigerator not your sound system. The main appliances that you’ll likely need to run always are the refrigerator, kitchen and cooking, heating and cooling, water heating, lights, and device charging.

How much energy do your solar batteries have?

The amount of energy your solar batteries can store depends on a few variables including the type of battery, the battery usage, the battery temperature, and battery maintenance.

Battery Type

There are various types of batteries including lead-acid batteries, lithium-ion batteries, and salt water batteries. Lead-acid batteries have been the most used battery for various decades and are relatively inexpensive. Compared to lithium-ion batteries, they have a shorter life-span and a lower depth of discharge. Lithium-ion batteries are the gold standard of battery storage. They are compact, lighter, and have a longer lifespan than traditional batteries. Saltwater batteries use saltwater electrolytes instead of heavy metals, making them more environmentally friendly. However, these are fairly new to the market and haven't been tested for reliability as much as lithium-ion and lead-acid batteries have.

Battery Usage

Most solar batteries are what are called deep-cycle batteries, which means they can discharge around 80% of their stored energy before they need a recharge. The lifespan of a battery depends pretty heavily on its usage. To ensure that you’re not cutting the life expectancy of your battery short, be sure to never entirely drain your solar battery of power. It is best to keep at least 5%-10% of charge on the battery at all times. This helps prolong battery health.

Battery Temperature

Like most electrical things, batteries are sensitive to extreme temperatures. Where you store your battery, and how much heat and cold it gets, can greatly determine its overall lifespan. Additionally, if your battery is kept at an optimal temperature, it will function at maximum efficiency. Generally it is best to keep your batteries indoors, especially if you live in a climate with extreme and varying temperatures, like hot summers and cold winters. If you live in an area with a mild climate, you can get away with storing your batteries outdoors.

Battery Maintenance

To keep your battery running efficiently for its entire lifespan, it is crucial to keep up with the maintenance needed. In order to maintain your solar system costs between $150 to $300 yearly, which seems like a lot until you compare it to preventable issues that cost up to $3,000. Opt for professional upkeep methods in order to ensure that you are getting full use from your solar power system.

Optimize Your Solar Batteries With SolarUnion

Get the most out of solar panel and battery systems with the experts at SolarUnion. Our trusted team of professionals are here to help you optimize your battery usage for efficient and seamless electrical output when you need it most.

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