How Many Solar Batteries Do I Need to Run a House?

It’s tough to give a straightforward answer to this question. When it comes to the number of solar batteries needed it is the same as with solar panels, it depends on your situation and what you want to get out of energy storage.

To get the exact answer to your question you must realize what you actually want from your solar/storage system. In general, you have three ways to optimize a battery system:

• To save the most money – 2 to 3 solar batteries are needed;
• For resiliency – usually only one solar battery;
• For self-sufficiency (off-grid) – 8 to 12 solar batteries are needed.

In this article, I will try to outline the major factors that contribute to the size of your battery system.

Solar battery system for saving money

If your purpose is to have a battery system that will save you as much money as possible then you will need enough energy storage to keep your home self–sufficient during peak electricity pricing hours. Peak pricing hours usually depend on the area where you live and the exact plan you are on.

However, in most cases, you will need around 2 or 3 lithium-ion batteries to avoid using grid electricity during peak hours or when your solar panels aren’t producing power.

It is important to note here that this doesn’t mean you are completely self-sufficient and don’t need a grid at all, it just helps you maximize your solar panel system and use as much solar electricity as possible.

Solar batteries and feed-in tariffs

Solar batteries are use instead of a feed-in tariff. You can also be grid connected and apply for a feed-in tariff, but any excess energy you produce through the day will be stored in your battery for use at night.

A feed in tariff can help above and beyond this bu tit will have a minimal impact on savings.

Solar battery system for resiliency

With this option, you will design a solar battery system that will be used as a resiliency tool for when the grid goes down. With this type of battery system, you can keep your house and essential appliances energized through extreme weather conditions and grid failures.

The number of batteries needed for resiliency reasons depends on how resilient you want to be if you want to keep just a few things running during quick outages then a single average lithium-ion battery will finish the job, but for longer outages that could last for days, you will need more storage.

Solar battery system for self-sufficiency (off-grid)

If your purpose is to create a battery system that provides full grid independence then you will need a significantly larger battery bank compared to other cases.

How many solar batteries you will need to go off-grid depend on how many loads you want to be powered and how long you might need to stay battery-powered.

Anyway, an off-grid storage system requires lots of solar batteries installed, especially if you want a capacity for extra-long periods without sunlight. A minimum amount of batteries is 8 to 12 lithium-ion batteries.

Factors that impact the solar battery system sizing

There are a few universal factors that impact how many solar batteries you should get for your solar storage system. They are listed and explained below:

Electricity loads

Anything that consumes electricity in your home is “load”. This includes appliances such as refrigerators and air conditioners. Depending on what you need powering, you will need more or less storage capacity. It is important to know how much electricity you need to provide to your appliances when designing a solar battery storage system.

Size and production of the solar panel system

You can charge up the batteries with electricity in two ways, to pull from the grid directly or charge it via a solar panel system. Charging the battery with solar energy is the way to go if you want to save money or build up resiliency in your home.

Before building your storage system you must ensure what is the capacity of your solar panel system during the day. If you need more storage capacity than your panels can fill you might need to install more solar panels to get the full benefit from your solar energy storage system.

Individual needs

Knowing what you are looking to get out of solar/storage systems is essential when you are deciding how many solar batteries you need for your system. However, systems designed for resiliency and savings can be significantly smaller than off-grid systems that need the most batteries.

FAQ’S

How many solar cells are needed to power a house?

The average solar system for a 2,000-square feet house consists of 16 to 21 panels, but the exact number depends on several factors such as the area you are living, how much energy you typically use, and how much power your panels can generate.

Can I run a whole house only on solar power?

Yes. High-efficiency solar panels and solar batteries are available on the market today and can provide a whole house run on solar power.

How long do solar batteries last?

Home solar battery lifespan is anywhere between 5 and 15 years.