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Answering your questions about solar batteries, installers and more.

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FAQ Glossary

Answering your questions about solar batteries, installers and more.

What different types of batteries are available?

Lithium-ion batteries

Lithium-ion batteries are becoming a popular choice for use with household solar panels and may become the main technology used in the future. Lithium-ion technology has been used for many years in portable devices, including in laptops and mobile phones. Due to falling costs and increased production, they can now be manufactured in larger sizes and are well suited to storing solar power.

Lead-acid batteries

The technology behind lead-acid battery storage is similar to that of a car battery. Lead-acid batteries are commonly used with solar panels in remote rural homes, where connection to the grid is prohibitively expensive. Thanks to advances in technology, systems well suited to solar power storage are readily available in the form of low-maintenance sealed lead-acid batteries.

What does battery capacity mean?

Typically, battery capacity is expressed in kilowatt hours (kWh), similar to the way your electricity is charged on your bill. Some battery manufacturers express their capacity in ampere hours (Ah). If this is the case, speak with your accredited designer to get this converted to kWh.

The battery capacity quoted by the manufacturer is an ‘ideal’ number that is useful for comparing batteries. Some manufacturers promote their battery capacity based on the total capacity, for example 10 kWh. But all solar batteries have what is called depth of discharge (DoD). This is how much of the total capacity can be used.

The majority of solar batteries cannot have 100 per cent of the total energy drawn out of the battery. DoD is expressed as a percentage of the total capacity. If a 10 kWh battery has a DoD of 80 per cent, it will provide 8 kWh of usable energy. It is important to compare batteries based on their usable energy, not on the total capacity.

Lithium-ion batteries typically have a depth of discharge of 80 per cent and above. Lead-acid batteries typically have a depth of discharge of 30–50 per cent.

How big are solar batteries?

A number of solar battery solutions are available. They come in a range of sizes (typically between the size of a split system air conditioner and a fridge) based on the technology that they use and the amount of energy they store. Lead-acid batteries tend to be physically larger than lithium batteries.

Should I go 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 solar 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 panels and batteries.

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.

Where can I install a solar battery?

Some solar batteries can be wall mounted, others are floor standing and some are best located inside, while others should be installed outside. You may also choose to install multiple batteries to increase your storage capacity, in which case you will need extra storage space.

Lead-acid batteries tend to be physically larger than lithium batteries and are usually installed outside or in a utility room (e.g. garage or basement) as they vent hydrogen when charged. Some batteries (usually lithium batteries) are designed to be wall mounted inside a utility room, which helps control their temperature.

If your battery is designed to be installed outside, it will come with a weatherproof enclosure, though you will still need to find a suitable place to install it. This will need to include access for electrical wiring, consider flooding/splashing of the enclosure, preferably be out of direct sunlight and not be adjacent to heat or ignition sources.

If your battery is installed inside, you may also need to consider ventilation. It is recommended that solar batteries not be installed in a habitable room, like a living room or bedroom. These are all factors to consider when you talk to a Clean Energy Council Accredited Designer.

What considerations should I be aware of when installing a solar battery?

The cabinet or housing of the solar battery should be built to comply with the standards and building codes applicable in the relevant jurisdiction. For example, in the Australian Capital Territory, the battery enclosure must comply with fire and building regulations. Your Clean Energy Council Accredited Designer will be aware of these requirements.

The cabinet or housing of the solar battery should be built to comply with the standards and building codes applicable in the relevant jurisdiction. For example, in the Australian Capital Territory, the battery enclosure must comply with fire and building regulations. Your Clean Energy Council Accredited Designer will be aware of these requirements.

What happens if I move house?

It is possible for a solar battery to be moved if you change residence, in the same way that solar panels can be moved. However, if the product standards change and your solar battery no longer meets the new standard, you won’t be able to reinstall it. Therefore, while it is technically possible to move your solar battery to a new residence, you should check before you move that you will be able to reinstall the system. If the system is to be moved, it must be carefully uninstalled and reinstalled by an accredited installer.

Do batteries make noise?

Batteries themselves do not make much noise, but the systems attached to them – like the inverter – may make some noise. You may hear the cooling fans and an electronic ‘buzz’ from the circuits, but it should be fairly similar to a regular solar inverter.

How long do solar batteries last?

Product warranties on solar batteries vary widely and are generally anywhere from 2 to 10 years. While a solar battery will often last longer than its warranty, its ability to store energy will gradually reduce over time with use.

As well as the product warranty, the retailer you purchase the product through should offer a retailer warranty. Warranties offered by retailers vary, including how they define the life of the battery. Some retailers offer a warranty as an ‘energy throughput’ figure, which means that they guarantee their batteries will store and deliver a given amount of energy, no matter how quickly that limit is reached. Energy throughput for lithium-ion batteries ranges from 4000 to 6000 cycles (charges/ discharges of the battery) at 80 per cent discharge rate, meaning an expected life of more than 10 years for high-performing systems (if cycled once per day). Some battery retailers offer a warranty guaranteeing either an energy throughput or a lifetime in years, usually based on whichever limit is reached first.

Will the solar battery change the performance of my appliances?

Once your solar battery is installed, your household electrical appliances will continue to operate as normal. If you are looking to go completely off the grid, you will need to consider how much power your appliances use and should speak to a Clean Energy Council stand-alone system Accredited Designer to design a system to meet your needs.

Will my solar battery work in a blackout?

Not all solar batteries provide backup power. Some will work during a blackout, and some may operate following a brief power outage. If you need your solar battery to operate during a blackout, make sure you discuss this with your system designer and choose an appropriate product. If you want an uninterrupted supply of electricity, you’ll need to install an uninterruptible power supply (UPS) solar battery. As UPS solar batteries are typically larger and more complex to install, they will cost more than other systems.

If your battery is charged during a blackout, it may be able to supply power to your home. However, you might not be able to run as many appliances as normal, depending on the rating of your solar battery. You may also want to conserve power for important appliances like your fridge.

Some solar batteries can power your whole house in a blackout, or some may have a power point that you can plug appliances into. Alternatively, your installer may need to wire specific appliances so you can use them in a blackout. It’s important to discuss your needs with your designer to make sure your system meets all of your needs.

Some systems may have a slight disruption in power (usually a couple of seconds) between the blackout occurring and the battery ‘kicking in’ to supply power. Appliances with clocks or on a timer (e.g. washing machines or dishwashers) may need resetting after a blackout.

If you are looking to go completely off the grid, make sure you speak to a Clean Energy Council stand-alone system Accredited Designer. Stand-alone or off-grid systems are typically more complex than standard household systems and present some different considerations.

Should I get a solar battery if I am on a feed-in-tariff?

One important consideration when adding a solar battery to an existing solar panel system is the impact this may have on your existing solar feed-in tariff.

The feed-in tariffs offered differ from state to state, and from retailer to retailer. In some states, the government regulates a minimum rate, while in other states it is up to you to negotiate a deal with your electricity retailer. It is worth shopping around to find out which electricity retailers offer better rates for solar customers.

A Clean Energy Council Accredited Designer will be able to calculate your potential savings as part of their load analysis. Many factors – including the size of your system, how much electricity you export and the feed-in tariff amount – will impact on how much money you save. Your system designer should consider all the relevant factors when providing you with an estimate. The actual savings you make may also vary depending on the electricity retailer you are with.

If you have a choice of feed-in tariff, choose the one that minimises your total energy cost. A Clean Energy Council Accredited Designer will be able to help you calculate what is best for you. You can also contact the relevant state government departments for more details on feed-in tariffs in your state.

ACT: Environment, Planning and Sustainable Development Directorate

NSW: Division of Resources and Energy

NT: Department of the Chief Minister

QLD: Department of Energy and Water Supply

SA: Department of State Development

TAS: Department of State Growth

VIC: Department of Environment, Land, Water and Planning

WA: Public Utilities Office

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