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Solar energy produces minimal greenhouse gas emissions and can help you reduce your dependency on fossil fuels. What’s more, you can make the most from solar panels when the sun isn’t shining by installing solar batteries to capture and store the energy from your solar panels for when you need it.

Being able to store enough power to meet your household’s electricity needs is critical, but how do you know which type of battery is right for you?

What is solar battery storage?

a home solar battery system on a brick wall

Solar energy storage systems work on the same principle as other batteries. Essentially, they give you an easy way to stockpile electricity, which you can use later as required. This gives you a reliable cache of solar-generated power to fall back on during the night or on dark and cloudy days.

There are a few different types of battery energy storage that may be appropriate for your solar system, depending on your budget and energy needs:

  • lead-acid batteries. One of the oldest and more common types of solar batteries, lead-acid batteries are cheap but slow to charge, require regular maintenance and don’t last as long as other batteries.
  • lithium-ion batteries. In recent years, lithium-ion batteries have begun to overtake lead-acid batteries due to their longer lifespan and greater storage capacity in comparison to their size. While more expensive than lead-acid batteries, they have become cheaper in recent years.
  • liquid ‘flow’ batteries. Flow and flywheel batteries use liquids to store energy. They’re easily maintained and the longest-lasting type of solar battery, but they’re the most expensive and don’t generally store as much energy as lithium-ion batteries.1

How do solar batteries work?

a roof with solar panels

Most home solar battery systems need an inverter that turns the raw power generated from the solar panels (a direct current or DC power) into electricity that can be used by your home (alternating current or AC). The inverter then directs any unused solar energy into your batteries during the day.2

When the sun goes down and the solar panels stop producing power, your inverter will ‘turn around’ and power can be drawn from your solar batteries to power your appliances as you need it.

Inverters typically last 10 to 15 years before they need to be replaced.3

Apart from your solar batteries and panels you’ll likely still require a connection to the local energy grid. This is so you can draw on electricity from these power poles and wires in case you run out of solar power from your batteries.

Depending on your solar system and batteries, you might be able to adjust some settings in real time to control a few things. For example, you might want to change:

  • where the solar energy generated is sent (either to your home battery storage or to the local grid – more on this below)
  • how much solar energy you use from your batteries during the day – this can be handy if you want to set a cap to make sure you have some ‘juice’ left in your solar batteries for tomorrow

When it comes to how to charge your solar batteries, they normally charge automatically based on how much sunshine the solar panels receive and the power they generate. Using your inverter, you can potentially charge the battery system faster by only using power from the local energy grid (if your home is connected).

If your batteries are fully charged and can’t store any more power, and you can send power to the grid, then your inverter will flip to sending additional power to the local grid until you adjust the settings and draw on your own battery power. Otherwise, this excess power could be ‘lost’.

animated illustration showing how solar batteries work

What are the benefits of investing in a battery storage system?

By storing solar energy, your battery allows you to harness even moresolar power from the sun. This means you need less electricity from the energy grid, which can help you reduce your energy bills.

If your solar battery inverter is off grid, you can potentially use the power stored in your battery during a blackout.

Another benefit for homes and businesses is that they can send more solar power to the grid. This means you can potentially earn more from solar feed-in tariffs, where your state government pays you for the energy you generate from your solar panels.

Solar batteries, in conjunction with a feed-in tariff, can help offset the cost of your household’s energy bills, or create a small stream of passive revenue if you’re a business.

Frequently asked questions

Are solar batteries worth it?

Solar batteries can help you get more out of your solar panels. A home solar system can pay itself off in seven to nine years, or as quickly as five years if you receive a solar rebate from your state or territory government, which helps reduce costs.4

Given enough time, solar batteries can definitely be worth it from a financial sense – plus they help reduce your reliance on fossil-fuels and reduce your impact on the environment.

How much do solar batteries cost?

The cost of solar battery systems for homes and small businesses will vary based on the type of battery and its size, though costs can range from $2,000 to $10,000 or more. Smaller lead-acid batteries are cheaper but only provide 3-5kWh of electricity, while larger capacity liquid flow batteries (10-20kWh) will cost much more.

How long do solar battery home systems last?

Solar batteries will last for different lengths of time, typically ranging from two to 10 years. While solar batteries do eventually die, proper maintenance and use can help prevent your system from needing a replacement battery before its expected life cycle ends.

For example, charging your battery too frequently can shorten its lifespan.

What size solar battery should I get for my home?

You should get a battery that matches both the output of your solar panels and your consumption needs, and not necessarily just the biggest battery that you can get.

As an example, if you have a 5kWh solar system and consume 20-25kWh of electricity, you might install a 13.5kWh home battery system, as noted in the NSW Home Solar Battery Guide.5

You should contact a professional to assess what size and type of battery suits your needs.

Can I use solar battery systems in my business?

Yes, businesses can use solar batteries to store power and use less electricity from the local network (reducing power bills). Businesses can also use feed-in tariffs to earn a little bit of money, which can help offset electricity bills or create a source of income.

Do solar batteries have a warranty?

Most solar batteries for houses and businesses have a warranty, which can last for a few years (though what’s covered can differ between manufacturers). It’s important you understand what’s covered by your warranty and what you need to do so your solar inverter and battery lasts as long as possible.

Is it possible to go off-grid by using a solar battery at home?

It’s possible, but difficult, to go completely off-grid, even with a solar battery system. You need to ensure that your solar panels generate enough power to meet your needs and that your batteries can store enough power for those rainy days.

Can you recharge solar batteries?

Yes, you can recharge a home solar battery. You should make sure you read the owner’s manual and talk to the installer to understand how to recharge it properly, so you don’t negatively affect its performance.

Compare energy prices with ease

If you have solar panels, you can compare energy plans for free in minutes with our comparison tools, including plans that have feed-in tariffs. We make it easy to weigh up available options by supply and usage charges, tariff types and feed-in rebates per kWh. Why not see what we have to offer and compare today?

Sources

1 NSW Home Solar Battery Guide. Department of Planning, Industry and Environment, Government of New South Wales. 2020.
2 About home solar batteries. Department of Planning, Industry and Environment, New South Wales Government. 2020.
3 NSW Home Solar Battery Guide. Department of Planning, Industry and Environment, Government of New South Wales. 2020.
4 Section 1: Why install a solar electricity system at home? Solar Panel (PV) Buyers Guide. Solar Victoria, Department of Environment, Water, Land and Planning, Australian Government. 2020.
5 NSW Home Solar Battery Guide. Department of Planning, Industry and Environment, Government of New South Wales. 2020.

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