Battery storage systems store electricity, such as from a solar system or the electricity grid, for use at another time.
Battery systems can vary in size:
Small battery systems can be installed with a new solar system or connected to an existing system. Note that some modification or replacement of parts may be necessary.
Battery technology has developed rapidly in recent years and this is expected to continue.
It's important to understand the type of battery storage systems available. Each have different installation and maintenance requirements, as well as different safety precautions.
Most home battery storage systems coming onto the market use lithium-ion (or Li-ion) technology. They have a long life and can store a lot of energy for their physical size. Mobile phones and laptops typically use lithium-ion batteries. Characteristics of lithium-ion batteries:
The most common and well known battery type has been around for decades. They work similarly to your car battery and have been used to provide back-up power in black outs and in remote areas. Some characteristics:
Depth of discharge
Round trip efficiency
Lithium iron phosphate
0 to 45 degrees
Lithium cobalt oxide
-10 to 45 degrees
Lithium manganese oxide
-10 to 45 degrees
-10 to 40 degrees
1 A battery suitable to supply energy is one which can store electricity for use over time. A battery suitable to supply power is one which can produce a high instantaneous output of electricity.
Adapted from CSIRO: Energy Storage Safety, Responsible installation, use and disposal of domestic and small commercial systems (2015).
These store energy in liquid electrolyte solutions that flow through the battery. They tend to be used in commercial and large-scale applications, and are more environmentally friendly than other batteries. Flow batteries have a life span of more than 20 years (approximately 10,000 charging cycles) and are about 80 per cent efficient. However, flow batteries are a complex technology and there is no recycling process or plant currently available in Australia.
These store energy using salt water-based chemistry. They are comparatively affordable, very safe and the most environmentally-friendly batteries on the market. Salt water batteries are 100 per cent efficient, but they tend to have a shorter life span (10 years), and are quite big and heavy. As with flow batteries, there is no recycling process or plant in Australia.
The price of batteries can vary greatly depending on the brand, type and size of the battery, and how advanced the technology is. Prices are expected to reduce as new products and manufacturers enter the Australian and Queensland markets.
It's important to understand the whole-of-system cost. For example, some advertised prices do not show the other components and installation charges you may have to pay. The whole-of-system costs can include:
As with any significant purchase, it's a good idea to shop around and get a better understanding of the different types of batteries, what they can do, and how much they cost to install. Ensure you compare like for like and not just cost alone.
Also consider the safety and performance of the battery. Cheaper batteries that have not been manufactured properly or tested to ensure they meet minimum safety or performance requirements may not be a bargain if they don't last or cause a safety hazard.
For more information, read about installing battery energy storage.
Batteries can be dangerous if they are not installed, used and looked after properly. It's therefore important to deal only with qualified and accredited battery designers and installers. The Clean Energy Council publishes consumer information about battery storage and safety (including an excellent customer checklist) that sets out the things you need to know about safely installing and maintaining a battery energy storage system.
In 2015 the Clean Energy Council commissioned the CSIRO to undertake a comprehensive safety performance study for different battery types. The report provides detailed advice on best practice for battery installations, maintenance and disposal.