Yes, in many cases it is possible to power an entire home by using solar batteries. Well, at least for a while. However, to be able to power all of your home appliances you will need the battery capacity to be good enough to cover your needs.
Whether your solar battery will be able to power your entire home or not, depends on the battery capacity, your power consumption, battery type and sunlight conditions throughout the day.
Let’s take a closer look at home battery systems and what to expect!
What is a solar battery?
Solar batteries, also called “home batteries”, are batteries that may store electric energy generated by your solar panels. By storing the energy, you will be able to use it at night when the solar panels stop generating electricity due to a lack of sunlight.
You can power your home with home batteries like the Tesla Powerwall battery without having a solar panel system. Some households store energy from the grid just to have backup energy in case of a grid power loss.
Why should you have a solar battery?
By having a solar battery, you can achieve greater energy independence. In case of a power outage, where there is no electrical power from the grid network, you will still have electricity to run your home appliances.
A solar battery can also be handy for anyone with solar panels on their roof. If you add a battery, you can increase your self-consumption rate and use less (or no) power from the grid.
If you have a solar panel system without a battery, you will normally need to import electricity from the grid as soon as the sun sets. With a battery, you can save money by achieving lower electricity costs.
However, solar batteries tend to be very expensive. Because of this, many Australians have solar panel systems with no battery included. In some states, you might be able to get battery rebates when installing a battery, and this can make the battery more affordable.
What battery capacity do you need to power your entire home?
To reduce your power costs as much as possible, it is important to choose the right battery capacity for your home. To be able to find the right battery size, you also need to know how much electricity your household consumes every day.
An average Australian household normally uses around 16 kWh of energy on a daily basis. If you are not at home during the day (at work etc.), you probably use around 30% of this energy while the sun is up. In other words, 70% of your electricity is imported from the grid.
Based on this example, you should find a solar battery that is able to cover 70% of your daily power consumption – which equals to 11 kWh. In other words, you would need a battery with a storage capacity of 11 kWh to power your entire home with batteries throughout the night.
A Tesla Powerwall 2 battery has a 13.5 kWh capacity, and will normally cover the needs of an average Australian household. But remember, if your home has a pool pump, a huge A/C system or an electric vehicle, you might need a bigger battery capacity. If so, you can add more batteries.
For how long can I power my entire home with batteries?
Normally a home battery will only be able to power your entire home for a limited period of time (between sunset and sunrise, for instance). The length of time a battery can power a home depends on your energy consumption.
When the battery is discharged, it will need to be recharged before it can deliver more power. As the sun rises and the sunshine hits the solar panels, the battery will recharge. The solar panels will run your home appliances while the sun is up, and excess energy is sent to the battery.
If you have a Tesla Powerwall battery, you might get a “whole home backup”, which means the Powerwall system will provide your entire home with backup power for 4-6 hours in case of a power outage.
The Tesla Powerwall battery can support your 120 V loads, including small appliances and lamps, but also heavier 240 V loads like pool pumps and electric vehicle charging systems.
Is a solar battery a good investment?
A solar battery is a great choice for anyone who prefers clean and green backup power, as the power is generated from a renewable energy source (the sun). However, the solution is rather pricey.
If 24/7 power access is important to you, a battery might still be a good investment. If a power outage occurs, you can feel safe that your home appliances will still work as they should. Make sure you use a CEC-accredited installer for obtaining quotes.