WHY INVEST IN A HOUSEHOLD BATTERY STORAGE SYSTEM?
Battery storage allows you to store electricity generated by solar panels during the day for use later, like at night when the sun has stopped shining. While batteries were first produced in the 1800s, the types of battery storage systems that can store solar power and provide electricity to households are fairly new.
Battery storage is an exciting new technology, but there are many things to consider before you invest in a system for your home.
Installing a battery storage system* can provide a number of benefits when used in conjunction with an existing or new solar panel system.
A BATTERY STORAGE SYSTEM CAN:
The significant reduction in the cost
of battery storage systems in recent
years means that installing a battery
is fast becoming a viable option for
many Australian households.
But what exactly are battery storage
systems, and how do they work to
power your home? This section covers
all the basics you need to know.
HOW DO BATTERIES WORK?
Battery storage uses a chemical process to store electrical energy, which can then be used at a later time.
For example, a solarpowered torch stores electrochemical energy during the daylight hours that can be used to provide light at night.
In practice, battery storage systems can operate in a number ofdifferent ways. It is important to discuss your needs with your Clean Energy Council Accredited Designer when choosing a system.
A battery storage system connects to a house in two main ways – DC (direct current) coupled or AC (alternating current) coupled.
A DC-coupled battery storage system is integrated into your solar system. These systems generally have a single inverter that converts the DC electricity to AC to supply your house, or feed back into the grid.
An AC-coupled system is separate to your solar system. It connects directly to your house wiring via its own dedicated bi-directional battery inverter, using local AC electricity to charge the battery and then discharge it directly to your house.
Each system has its own benefits. It is best to discuss the different options with your system designer.
WAYS TO PURCHASE A BATTERY STORAGE SYSTEM
WHAT DIFFERENT TYPES OF BATTERIES ARE AVAILABLE?
OTHER TECHNOLOGY TYPES
Other technology types include nickel-cadmium, nickel-metal hydride and flow batteries, but these are less common.
If you are interested in these types of technologies, the manufacturer or a Clean Energy Council Accredited Designer
will provide you with more detailed information.
HOW MUCH DO BATTERIES COST?
While the price of battery storage systems is falling rapidly, thevcost to install a household system is still significant. The fully installed costs of a system are likely to be around $1000 – $2000 per kWh.
ESTIMATED LITHIUM-ION BATTERY STORAGE SYSTEM PRICE
|System size||Estimated price range|
$5000 - $10,000
$10,000 - $20,000
Some providers may offer leasing arrangements or payment
plans, but make sure you check the details and ask for the total
costs of any plan.
Once installed, the cost of running a battery storage system is
minimal. It’s important to have a maintenance plan in place to
ensure your battery is running safely and efficiently, so speak to
your retailer about any ongoing maintenance costs.
BATTERIES: FREQUENTLY ASKED QUESTIONS
DO YOUR RESEARCH
Battery storage can be a great way
to get the most out of your new or
existing rooftop solar power system.
Different battery storage systems suit
different needs, so it’s important to
do your research and seek advice on
what’s best for you.
Some questions to think about and discuss with your designer when choosing a system include:
• What is the total installed cost of the battery storage system versus the expected output over its lifetime?
• What can you afford?
• What system best suits your tariff structure?
• Do you have an appropriate space to install the battery?
• Can the battery store and supply enough energy for your needs?
• Is the supplier a reputable company that can deliver on any potential warranty claims?
• Do you have any safety concerns?
• Can the battery be recycled?
In addition, questions to think about when choosing the right size battery include:
• What do you want to use the battery for
(e.g. backup for blackouts, saving money)?
• How much energy do you use between battery charges
(both now and in the future)?
• How much power do you need to run your appliances?
• How much excess energy do you generate from your solar panels each day?
As long as you stay connected to the electricity grid, you can continue to use your appliances to suit your lifestyle. Your energy needs will be met through the combination of grid electricity and your solar and battery storage system.
WHAT FEATURES SHOULD I LOOK FOR IN A BATTERY STORAGE SYSTEM?
HOW MUCH POWER DO YOU NEED FROM YOUR SYSTEM?
The key features to look at when comparing battery storage systems are:
• How do I know what the system is doing (i.e. what is the user interface?)?
• How is it intended to be used (e.g. some systems are only intended for providing backup power while others can only charge from your solar panels and not from the electricity grid)?
• How much energy can it store?
• How fast can it store and supply energy?
• What are the maintenance and safety considerations of the system and technology?
• How big is it and where does it need to be installed?
Your designer will help you understand the differences between systems and choose a system that is appropriate for your requirements.
Additional features you might want to discuss with your designer include:
• What is the battery storage system’s operating temperature range (some systems cannot charge in cold weather or may not operate on very hot days)?
• Can the battery storage system be recycled?
• How long will the battery storage system last, and what is the product warranty period?
• Would it be simple to add more batteries to the system down the track if your needs change?
• Is it an ‘all-in-one’ device or are there multiple components that must also be installed, including any programming to ensure compatibility?
• Does the battery storage system only work with a specific inverter or is it compatible with multiple brands?
• What is the efficiency of the system (how much of the stored energy can be used)?
When thinking about what you need from your battery storage system, there are two key concepts to understand:
• power – how fast energy can be supplied (kilowatts, or kW)
• energy – how much energy is stored by the system (kilowatt hours, or kWh).
Check your electricity bill for information about your existing energy use. A ‘typical’ house may use around 18 kWh of energy per day with a maximum power consumption of 4.5–15 kW, although this can vary significantly.
As long as you stay connected to the grid, your battery storage system does not need to provide for all of your needs.
Most battery storage systems currently on the market have a power rating of 2–5 kW, and an energy rating of 2–10 kWh.
Multiple systems can be used to scale this up if necessary. Your peak power demand will depend on how many and which of your appliances are used at the same time. Typical maximum power requirements of some high power appliances are:
|Typical maximum power requirements of some high power appliances are:|
2 – 5+ kW
1 – 2 kW
As a general rule of thumb, any appliance that cools or heats will
need more power than other appliances.
DO YOU WANT TO GO COMPLETELY ‘OFF-GRID’?
If you would like to disconnect from the grid completely and
supply your entire household with your own clean power, there
are a number of very important factors to consider.
Your solar system will need to be large enough to meet your
power needs and your battery will need to be able to cover your
requirements at all times, including peak periods. In most cases,
this means that you will need very large solar and battery storage
Large systems can present extra challenges, including their
physical size, town planning regulations and grid connection
requirements. Off-grid systems are more complex to design and
install, so speak to a Clean Energy Council Accredited Designer/
Installer with experience working with these systems.
You should also plan for a back-up if something goes wrong.
To find a qualified designer and installer, visit the Clean Energy
Council website and search for someone with ‘stand-alone’
FIND A RETAILER
It’s important to shop around before
buying your battery storage system.
Talk to different retailers of battery
storage systems about options and
obtain quotes, and if possible speak
to people in your area who have
had solar and storage installed.
Unfortunately, if the offer sounds too
good to be true, it probably is.
WHO’S WHO IN THE MARKET?
The main parties involved in the sale and installation of
battery storage systems are the retailer, designer and installer.
Sometimes these roles are filled by one individual, which may
be the case with small retailer businesses run by a qualified
designer/installer. However, two or three entities can be involved
with medium to large companies that subcontract out their
designs and/or installations.
CHOOSE A CLEAN ENERGY COUNCIL APPROVED SOLAR RETAILER
The Clean Energy Council Solar Retailer Code of Conduct helps
consumers choose a retailer that has committed to offer a high
level of quality and service. Selecting an Approved Solar Retailer
is one way to ensure that you will be dealing with a company
that prides itself on being an industry leader.
Make sure you select an Approved Solar Retailer that sells battery
energy storage systems as some of these retailers may only sell
Approved Solar Retailers:
• provide a five-year whole of system warranty
• use ethical sales practices
• only use Clean Energy Council Accredited Installers
• meet the very high standards of the Code of Conduct.
The Solar Retailer Code of Conduct has been authorised by the
Australian Competition and Consumer Commission.
To see which companies have signed on to the code,
IS YOUR DESIGNER AND INSTALLER CLEAN ENERGY COUNCIL-ACCREDITED?
Choosing an Approved Solar Retailer ensures that your designer
and installer will be Clean Energy Council-accredited.
The designer and installer could be the same person, or you could
speak first to a designer who will design a system based on your
needs, then a separate installer who will complete the physical
installation and connection work.
The safety of your solar and battery storage system is
paramount, so only work with properly trained and accredited
designers and installers. Your designer/installer should have
appropriate accreditation and experience in battery design and
Here is what to look for:
The Clean Energy Council accredits individuals for the design and
installation of battery storage systems. This is different to the
accreditation for solar design and installation. Someone who is
accredited by the Clean Energy Council to design and/or install
battery storage systems will hold either:
• grid-connect and stand-alone accreditation
• grid-connect accreditation and battery storage endorsement.
You can search for a designer/installer at
The Clean Energy Council has a Guide to Installing Solar for
Households that contains some useful information on purchasing
INSTALL YOUR SYSTEM
The first thing to do when having a battery storage system
installed is to ask to see the installer’s Clean Energy Council
Accredited Installer card. This shows that the installer is qualified to
install your battery storage system.
The installation process for a battery storage system is usually very
straightforward and only takes around 1–2 days (unless you are
having a large system installed, in which case it could take a few
If you are installing solar panels or upgrading your existing system,
you could reduce overall equipment and labour costs by installing
batteries and solar at the same time. However, if you’re not sure
whether you need a battery storage system now or in the near
future, you can still add it down the track. Let your solar installer
know that you may want to add storage in the future so that this
can be planned for during installation.
Make sure that you receive all the necessary paperwork during
installation. Documentation will be important if you ever need
to make a warranty or insurance claim. You should also receive a
system user manual when your system is installed, and make sure
you ask any questions before your installer leaves.
Your installer may need to switch off the power to your house at
some stage, but this period should be brief. If your electricity meter
or meter box needs upgrading, your power may need to be off for
The installation process shouldn’t pose any risks to your other appliances, provided everything is done safely.
Clean Energy Council Accredited Installers are required to have public liability insurance, but to avoid any insurance issues during the installation period, check that your installer has adequate insurance before they start work.
It is also worth contacting your home insurance provider before installation commences to make sure that your new battery storage system is covered by your policy.
CONNECTING TO THE GRID
Your solar or battery storage system supplier will usually arrange connection to the network on your behalf, including preparing and submitting all relevant documentation required from the electricity retailer and/or distributor for meter installation and connection to the network.
It is important, however, to be aware of the process involved, who to contact to follow up on progress, and to ensure that everything gets done on time.
Check with your installer what documents you will receive for the battery storage system.
SAFETY AND STANDARDS
Battery storage systems do have some safety risks, just like your solar panels or any other major piece of electrical equipment.
Provided your system is installed to all relevant Australian Standards and used and maintainedproperly, battery storage is safe, but it’s important to be aware of the risks so you can manage them safely.
SAFETY STANDARDS FOR LITHIUM BATTERIES
In December 2017, Standards Australia published a new standard for the safety of lithium batteries in residential and commercial applications – known as AS IEC 62619.
The standard requires testing under a range of extreme conditions, such as dropping the battery from a height, smashing it, firing a nail into it, overheating it, overcharging it and short circuiting the terminals. Batteries need to demonstrate they can withstand these extreme conditions without causing hazards such as fire, explosion, leakage, venting of flammable gases or rupture of the casing.
The standard also requires the manufacturer to provide important safety information for end users.
When buying a lithium battery, ask the retailer to verify that it has been tested to the new standard.
The main safety hazards to be aware of are:
• The general hazards of electrical wiring, just like other wiring in your house.
• Chemical, fire or explosion hazards. For a battery storage system, these are similar to the risks associated with bottled gas or a natural gas service. For this reason, don’t smoke around your battery storage system and check with your installer whether your system vents gases.
• Possible escape of non-flammable gases when charging or discharging lithium batteries. This may cause a risk of inhaling noxious gas similar to a natural gas leak if there is no ventilation.
• Chemical leakages similar to those from the corrosive fluid of a car battery orhousehold chemical cleaning products.
Like any other major electricity appliance, if you have small children or curious pets, keep them away from your battery storage system and don’t store any items on top of your batteries or wiring.
Your battery storage system may heat up slightly (like a laptop battery), but shouldn’t become hot to touch. Also, as with all electrical equipment, battery storage systems emit some level of electromagnetic radiation, within safe limits.
If an incident occurs with your battery storage system, in the case of fire or an explosion call 000 immediately. For minor incidents, such as a fault alarm or a malfunction, the system should be serviced by your Clean Energy Council Accredited Installer.
MAINTAINING AND ENJOYING YOUR SYSTEM
MAINTENANCE & SYSTEM MONITORING
Your battery storage system installer will set up your system and show you how it all works after installation, including different operating modes.
Your system may have settings that you can adjust. For example, you may wish to set your battery to only charge at certain times of the day and discharge at other times to coincide with how you use energy or to get the most out of your electricity tariffs. Not all battery storage systems have the same functions, so it’s important to choose one upfront that suits your needs.
Some minor upkeep and maintenance is important to keep your battery running efficiently and safely. Different battery storage systems have different requirements, but most battery maintenance is not difficult or onerous.
The maintenance should be performed by a Clean Energy Council Accredited Installer. In addition, it is a good idea to carry out visual checks at least once a month to keep your system in top condition. If you notice something is not right, call your accredited installer or battery storage system retailer.
You will need to understand how to interpret critical system health information and recognise when your storage system needs attention. Your installer should also give you a logbook or table to record the system’s critical measurements.
When doing maintenance on the system, the accredited installer can provide you with feedback on the system’s performance and help you to understand your usage and the system’s limitations.
If there is an internal failure in an individual battery cell, that cell can begin to perform poorly long before the system as a whole has a problem. Again, this is something that the installer can identify during maintenance of the system.
The lifetime of a battery is strongly dependent on how the system is used.Poor or heavy usage may mean the product does not last as long as the manufacturer’s specifications. The lifetime also depends on ambient temperatures.
All battery types should be checked during extreme hot or cold weather to see whether they are still performing as required. Batteries can be discharged over a large temperature range (-20°C to 60°C), but the charge temperature should be limited for best results.
Your electricity consumption may also change over time, which can alter the long-term performance and life of the battery storage system. Check with your accredited installer when the maintenance is undertaken in case your consumption has changed significantly (e.g. if more people are living at your property or you have purchased new appliances).
If you are unsure of anything about your battery storage system, please contact your accredited installer, who will be able to assist you.
It is important to keep an eye on how your battery storage system is operating.
Different manufacturers have different ways for you to do this:
• Some systems have a display on the battery storage system itself, with indicators such as operating mode and battery state of charge.
• Some systems support a remote display option that can be installed inside your house, known as an inhome- display. These systems are often combined with other information about your home energy use – such as air-conditioning usage, solar generation and tariff information.
• Some systems can connect to the internet and allow you to view information from your computer, smartphone or tablet, even when you’re not at home. Check whether your system has inbuilt WiFi or if you need a new data point installed.
In addition to monitoring systems provided by your battery storage system manufacturer, there are a number of third-party home energy monitoring solutions available.
WHAT IF SOMETHING GOES WRONG?
GLOSSARY AND DEFINITIONS
BATTERY STORAGE SYSTEM CHECKLIST
Know what type of battery storage system (i.e. battery
chemistry, power and energy size) you are having installed.
Different battery types have different requirements.
• Use a Clean Energy Council Accredited Designer/Installer with
the ‘battery storage endorsement’ to design and install your
• Understand what you will be using your battery for and
the amount of energy available for your use (this is usually
less than the manufacturer’s rated total amount of energy
labelled on the batteries).
• Monitor your system regularly (at least once a month) and
ensure that you:
– have an appropriate battery monitoring system in place
– have a log book and a visual and audible alarm
– know what to check for when doing a visual check or
taking meter readings.
• As batteries do not perform well with sudden changes in
ambient temperature, they must be appropriately housed
with adequate airflow. On extremely hot or cold days, you
may need to do additional monitoring. Ensure that you have
a system in place to remind you to do this.
• Ensure your batteries are not accessible to children, are
vermin proofed and are separate to the living areas of your
house. Do not store items on top of or lean items against
your batteries or enclosures because they could be a potential
electrical fire risk. Consider installing signs to remind you of
• Ensure that your batteries have the correct safety and
warning signs for the battery type, and that you know the
correct procedures in case of emergency (e.g. emergency
shutdown procedure and emergency action plan).
• Keep manufacturer, installer and warranty information to
refer to as needed, and only use Accredited Installers to alter
• Revisit your whole system periodically and replace or upgrade
components as required. Your Accredited Installer should be
the first point of contact for maintenance.