Trustpilot

How Many Solar Batteries Do You Need to Power a House?

Posted on 30 July 2024 by The Solar Co

Installing a solar battery is a great step towards a more cost effective way of producing and using energy for electricity. The concept behind solar batteries is that they store excess energy your solar panels have produced, keeping it in reserve for when is needed for a top up, such as cloudy days. Solar batteries ensure you benefit first from all the energy and electricity being generated, before being directed back to the grid for other uses. For this reason, investing in the solar panel system has a positive impact on your electricity bills, as you are less reliant on the grid and rising costs.

Yet determining the exact number of solar batteries needed to power your home isn’t a straightforward answer. It depends on a few key factors;

Understanding Your Energy Needs 

The first step is figuring out how much electricity your home uses day to day, and in peak hours. By looking at your current energy bills, you will get an idea of your average daily consumption. This will give you a baseline for estimating how many solar panels and battery capacity is needed . If you are a larger household, you will typically consume more electricity, and will require more batteries to store this.

Battery Capacity and Depth of Discharge

 Solar batteries are measured in kilowatt-hours (kWh), which measures the amount of energy they can store. It's important to consider the depth of discharge – how much of the battery's capacity you can use before it's damaged. You do not want to overheat a battery. Most batteries can be safely discharged by 80%. You also don’t want to run your battery to the ground, as it affects its lifespan. Therefore, consider investing in an additional safety back up battery, if you do have spurts of high usage 

Before investing in a solar system, considering installing solar panels and the number of solar batteries you will want to consider the following;

  • Lifestyle: Your daily habits, like when you use appliances, affect your energy needs.
  • Home size: Larger homes typically consume more electricity, so more panels and batteries will be needed.
  • Positioning: Positioning solar panels on a roof with direct exposure to sunlight and not covered by trees or shady spots will allow for more solar power generation. This can be used or stored in your battery.
  • Battery technology: Different battery types have varying capacities and lifespans. If looked after carefully, ensuring functioning battery capacity, typically 10-15 years lifespan.

Although it depends on the above basis, an estimate maybe;

  • Small homes (1-2 bedrooms): Often, a single battery with a capacity of around 5-8kWh might be enough.
  • Average homes (3-4 bedrooms): Most people find that a 10kWh battery is a good starting point.
  • Larger homes (5+ bedrooms): You might need 2 or more batteries, depending on your energy use.

Given the complexities involved, it's highly recommended to consult with a solar installer expert. They can assess your home's energy consumption, recommend suitable battery sizes, and design a system tailored to your needs.

While batteries store energy for later use, and solar panels generate electricity., it's essential to balance the two to maximise your system's efficiency. They work hand in hand, so ensuring your system is balanced rather than oversizing either component can prevent wasted energy or unnecessary costs.

Determining the precise number of solar batteries for your home requires careful consideration of various factors. Start by understanding your energy usage, and exploring battery options to then make an informed decision about energy storage investment.

Back to Blog