What Size Solar Battery Do I Need?
Today, the savviest homeowners aren't just installing solar panels, but maximising their investment with solar batteries. These devices store excess energy generated throughout the day for use during peak times when electricity prices are much higher.
As experienced solar installers based in Preston, PurelyPowered know what works in real homes and can help you understand the options.
Want to learn more? Keep reading as we explain how to choose the right sized solar battery for your system and energy needs.
What are the benefits of a solar battery?
So, why bother purchasing a solar battery when you already have panels? Solar batteries allow you to store energy for when you need it most – during peak-price times, at night or in the event of a power cut.
Key benefits include:
- Reduced energy bills
- Energy independence
- Backup protection during power cuts
- Environmentally friendly
How do solar batteries work?
In a nutshell, solar batteries capture and store the excess energy your panels generate during the day. Instead of exporting this unused electricity back to the grid, it’s held in the battery until you need it.
How much electricity can batteries store? This depends on their size. Battery capacity is measured in kilowatt-hours (kWh), the same unit as on your energy bill. A 5 kWh battery, for example, can deliver 5 kilowatts of power for one hour, or 1 kilowatt for five hours. Once the energy is used, your home draws from the grid as normal.
Key considerations when choosing battery size
There’s no one-size-fits-all when it comes to solar batteries. The right capacity depends on your property size, system and goals. Here are the main things to keep in mind:
- Household energy usage – Think about how much electricity you use each day. For example, a family that uses 12 kWh daily will need a larger battery than someone living alone who uses 5 kWh.
- Solar panel capacity – Your panels can only produce a certain amount of energy. If your battery is too big, your panels may not be able to charge it fully.
- Budget – Larger batteries have a higher upfront cost. There’s no point in wasting money on the biggest option if a smaller one will suit your energy demands.
- Future needs – If you’re thinking about getting an electric car or building an extension, choose a bigger battery so you’re ready to scale up.
Solar battery sizes explained
Most solar batteries produce between 3 kWh and 15 kWh of energy. The right choice depends on how much energy you use and the maximum capacity of your panels.
- 3 to 5 kWh – A good fit for smaller homes or households with low electricity demands
- 5 to 10 kWh – The most popular range for average families, enough to cover evening and night-time use
- 10 to 15+ kWh – Best for large properties with high-demand appliances and electric charging ports
A good rule of thumb is to check your annual electricity usage on your bill, divide it by 365 and match your daily kWh consumption to a battery size. For example, if your household uses around 9 kWh a day, a 5 kWh battery could comfortably power your evening usage, while a 10 kWh system might cover almost all of it.
Find the right battery size with PurelyPowered
The best solar battery is the one that matches your household’s energy needs, budget and future plans. As experienced, MCS-certified and TrustMark-registered installers, PurelyPowered have helped hundreds of homeowners across Lancashire maximise their solar investment. We provide honest advice, bespoke solutions and ongoing local support, so you know you’re in safe hands.
If you’re still unsure, our friendly team can answer all your questions and provide a clear, no-obligation quote. Contact us today.
