When choosing a solar battery, it is important to find the right size. Solar batteries are available in a number of different sizes, and the size will decide how much energy the battery is able to store (in kilowatt-hours / kWh).
So, what battery size do you need? Here is everything you need to know!
First of all: Who will need a solar battery?
Whether you will need a solar battery or not, depends on what kind of solar panel system you have. When installing a solar panel system, you will be able to choose between a grid-connected, stand-alone or hybrid solar system. This is the first step in determining the right size battery.
Grid-connected solar panel system (without a solar battery)
With a grid-connected solar system, your solar panels will produce electricity when the sun is shining, and this energy can either be used directly or transferred into the grid. In other words, excess energy goes to the grid. In return, you will get a feed-in tariff.
If you need more electricity than your system produces, you can import energy from the grid. A system like this does not require a solar battery.
Stand-alone or hybrid solar panel systems
Around one-fifth of all Australians have a stand-alone or hybrid solar panel system – systems that will require a solar battery of the right size.
If you have a stand-alone solar panel system with a battery, there will be no grid connection. The energy produced by the panels will be used directly, and excess energy is stored in the solar battery. The stored energy might be used later when the system is not generating electricity (during the night etc.).
When having a hybrid solar panel system, it should have the right battery size and at the same time be connected to the grid. Excess energy will be stored in the battery. If the amount of power exceeds the battery capacity, it is sent to the grid. In return, you will get a feed-in tariff.
How to choose the right battery size?
Choosing the right battery size for your system will depend on a number of factors. In most cases, your solar installer will help you find the right battery size. Here are the most important factors:
- The size of the solar panel system
- Your household’s energy consumption
- Power usage pattern
- Budget
Solar panel system and the right battery size
When installing a solar system with a battery, it is important to pair the system with the right battery size. A big solar panel system will usually be paired with a bigger battery, while smaller systems can use smaller batteries.
For instance, a 5 kW solar panel system will normally benefit from having a solar battery with a 10-13.5 kWh capacity. The right battery size will depend on your needs and energy consumption.
Energy consumption
If your household uses a lot of electricity, a big solar battery might come in handy. That way you will be able to store a bigger amount of energy when the sun is shining, and you can use this whenever needed.
Usage patterns
Your usage pattern is also relevant when considering what solar battery size to choose. Remember, most of the electricity is produced in the middle of the day (when the sun is shining). However, many Australians are not at home during the day.
For Australians with a grid-connected solar system with no battery, around 2/3 of all the energy is transported to the grid. When coming home from work, the sun might not still shine, and you will need to import electricity from the grid.
If you use much of the energy during the night, it might be better to choose a solar system with a battery of the right size. That way you can store the energy in a battery, rather than sending it to the grid.
A typical 5 kW solar system produces around 17 to 21 kWh a day in Australia. If 2/3 of this is not used directly, it will add up to 13 kWh of power – which can be stored in a 13 kWh battery. If you use less energy during the night, you might get away with a smaller battery, like 10 kWh.
Price and budget
When choosing a solar battery, your budget will also be relevant. Solar batteries are expensive, and bigger batteries will normally cost more than small batteries.
Also, keep in mind that there are different solar battery types, and some are more expensive than others.
Use a solar battery size calculator
A solar battery size calculator will help you find the right battery size depending on your solar system and needs. By using a calculator, you will be able to estimate what size you need, and what the final cost most likely will be.
Alternatively, your solar installer can do the calculations for you. Find a solar installer today, and start planning your home battery system!