Getting started with Battery storage

Solar battery storage explained

There has never been a better time than now to look at an NRG Solar storage system for your home or business.

Advances in technology, coupled with a thriving green energy sector, mean that battery storage systems are more affordable and efficient than ever.

The information on this page is for anyone who:

  • Would like to reduce their home or business power bills further
  • Is interested in reducing their reliance on grid power
  • Is passionate about renewable energy and sustainable living
  • Has a business paying a loading for maximum grid power demand
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How does a solar battery storage system work?

Without battery storage, any excess power produced by your solar system during the day is exported to the power grid. After dark, the panels stop making power and the home or business uses electricity from the grid.

However, with a solar battery storage system installed, any unused solar power generated through the day is stored in the battery for later use.

The solar process

How our solar & battery systems work


Solar panels convert sunlight into Direct Current (DC) electricity. Solar panels are installed on your roof and positioned to receive maximum sunlight. Good quality solar panels can last 25 years or more.


The inverter converts DC electricity from the panels into Alternating Current (AC) electricity, which we use in our home appliances, store in a battery or export to the grid.


Store excess electricity in your battery for use in the evening. If the battery is full, the excess electricity is fed back to the grid. A battery can also provide electricity to your home in a black out.


A smart meter is used by your electricity retailer to measure the flow of electricity in and out of your home. It sends this information back to your retailer remotely, without your meter needing to be manually read.


The grid is the network of poles and wires that carry electricity. As well as buying electricity, you can export excess electricity into the grid and get paid a feed in tariff from your electricity retailer.

Benefits of NRG Solar clean, green power

The benefits of storing your own clean, free electricity are many, including the ability to:

  • Slash your electricity bills even further
  • Dramatically reduce your carbon footprint
  • Become energy independent
  • Protect yourself from power price increases
  • Improve your energy security (eg. blackout protection)
  • Reduce your peak demand (for businesses)

Can I add a battery to my existing solar power system?

NRG Solar can help you add a battery to any solar power system. If you have a ‘battery ready’ system, it means your existing inverter can easily handle the addition of battery storage.

For ‘battery capable’ systems, it means that a battery inverter is usually required. Some battery systems, such as Tesla Powerwall, come with an inbuilt inverter. Even older systems may be made battery capable.

We would do an on-site assessment of your system and help you calculate the costs and savings.

Importantly, we would also take into account the effect on any existing warranties, the size of your existing system, your current feed-in tariff and other considerations.

BOOK A Free On-Site Quotation
Tesla Powerwall
Tesla Solar battery system.

NRG Solar are a Tesla Premium Certified Installer - one of the first in SA to reach this status. Tesla Powerwall works to continuously power your home day and night, and also in the event of a grid outage.


Solar battery system

BYD is one of the world's largest lithium-ion battery manufacturers. Battery-Box is modular system allowing you to scale your energy storage to suit your needs.


How much does a solar battery storage system cost?

At NRG Solar, we design and install energy storage solutions for a range of scenarios. From homeowners who want to save money and live more sustainably, to business customers who want to reduce their maximum power demand or have blackout protection.

What is the payback period on a solar battery?

The payback period will vary from system to system based on the system size and usage. But it’s common to see payback periods as short as four years. After that, you are enjoying free electricity for years to come. For some customers, the payback period is even shorter.

This is not only because battery storage can help to reduce the payback period on your solar panels and inverter. It’s also because your battery system, coupled with the NRG battery monitoring app, helps to drive lifestyle changes and positive power use behaviours.

Customers using the NRG battery monitoring app save even more because they can see their system in operation and the effect of their energy use. But don’t worry—you don’t have to be a solar technician!

With an NRG Solar storage system, you are equipped to maximise your savings, enjoyment and comfort with:

  • An easy to use, powerful monitoring app that shows your system in real-time operation 
  • Practical, step-by-step handover training in language everyone can understand
  • After-install technical support anytime you have a question.
    (Remember, we’re local, like you!)

Will batteries get cheaper over time?

A common misconception is that batteries will get more powerful and become cheaper over the next few years. This was certainly true five or six years ago, but unfortunately no longer the case. In fact, the last three price changes in South Australia saw the cost of battery systems go up each time.

Battery manufacturers, such as Tesla and BYD, already supply millions of batteries a year. Therefore, their investment in cost reductions through manufacturing automation and supply chain improvement has already been done. Plus, demand for their products is rising year-on-year.

For this reason, the solar industry expects battery prices to continue going up in the years to come.

At the same time, battery incentive schemes may be likely to reduce and there is no guarantee that solar rebates will remain unchanged. (Scroll down the page for information about the SA Home Battery Storage Scheme.)

All of this adds up to why NOW is a great time to join the solar battery revolution.

Are there other reasons to invest in solar battery storage?

Aside from savings, there are many other compelling reasons that a solar battery makes sense:

Blackout protection

Some people choose to get a solar battery for energy security. For example, they may have medical devices, appliances or work equipment they rely on.

Environmental impact

An increasing number of people install solar batteries for conscientious reasons. They want to reduce their environmental impact or enjoy life’s creature comforts without feeling guilty about carbon emissions.

New home expectations

Around 40% of all new solar power systems we install include battery storage. The growing expectation among homeowners, especially with luxury homes, is that the property is energy friendly.

Price rise protection

Continuous electricity price rises can be infuriating. Yet another great reason to take power production into your own hands.

What solar batteries do you recommend for Adelaide and South Australia?

After extensive testing, we recommend and install Tesla Powerwall and BYD Battery Box solutions for Adelaide and South Australian homes.

Both companies are world leaders in the renewable energy space. Tesla is renowned for its electric vehicles and home battery storage systems, while BYD is a titan in large and small scale energy storage.

With Tesla Powerwall and BYD you get top performance from the best battery storage systems on the market. And when you choose NRG Solar, you get total peace of mind that your battery system has been designed and installed by Adelaide’s trusted solar expert.

Just how expert is NRG Solar?

We are one of the only national recipients of the Tesla Premium Certified Installer status. Very few solar companies in Australia are recognised by Tesla at their highest level.

As for which system would suit your home or business, an NRG Solar consultant would be pleased to meet with you to discuss your requirements, and show you how the different systems work.

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Solar battery Adelaide installation standards

The Australian Standard for solar energy storage installation is called AS/NZ 5139 2019. It was introduced in 2019 as an important consumer protection against fire and other associated risks.

At NRG Solar, we are enthusiastic about formal safety standards. That’s because we are also solar repair specialists. Over the years, we’ve fixed thousands of orphaned systems installed by other companies. The workmanship we witness is often lazy, unskilled or straight out dangerous—the type of negligence that could result in injuries or fatalities from fire or electrocucion.

That’s one reason you should never buy solar over the phone. If the day of installation is the installer’s first time on site, there are bound to be surprises, delays and extra costs. From the correct position of the system, to the surface on which the system is mounted and more, it is very difficult for an installer to guarantee compliance with the Australian Standards without arriving fully prepared.

We don’t like surprises. You shouldn’t either.

As with all things involving electricity, the safe installation of solar batteries cannot be overstated. That’s why NRG’s team of installers are certified solar electricians. Plus they receive ongoing training in the latest compliance standards and technologies.

The NRG Solar promise is that there are no compromises on safety or quality—and no surprises—along the way. You know it’s going to be done right. You’re going to get a turnkey solution with smooth project management from start to finish.

How many solar panels do I need to charge a battery?

There are of course averages, but we like to remind people that how much power you need to charge a solar battery has less to do with the number of panels on your roof, and more to do with how much surplus power your panels generate.

For some households, systems as small as 4 kW will generate enough surplus electricity through the day to be stored in a battery, while other households would need a bigger system and more panels.

The reality is that every household’s energy use is different.  This is why there is not one size of system to suit every home or business. 

The key is to talk with an NRG Solar battery expert who can assess your energy needs and design a tailored system for your situation.

How long can a battery power a home?

Before diving into how long a solar battery can last, let’s first look at how much electricity the average Adelaide home uses.

The daily average electricity usage for South Australia is 19 to 20 kWh during summer and winter, and 15 to 16 kWh in the milder months of autumn and spring. Most of that power is used in the peak hours between 5 pm and 10 pm.

The key time for drawing on stored energy is of course after the sun has set. This is when your rooftop panels are no longer making electricity. After dark, the average South Australian home uses around 8 kWh of electricity in the milder months and 9 kWh in summer/winter.

Now, consider those numbers against a 13.5 kWh solar battery. Assuming the battery is fully charged during the day, it will have plenty of clean, green power to keep the average home running all night!

The benefit of solar monitoring

If you were ever worried about suddenly running out of power overnight, you don’t need to be. NRG Solar solutions come with a monitoring app that shows your battery reserve and usage in real-time.

Not only does the NRG app keep you updated about your energy reserves, it provides powerful insights into how much electricity your household uses. Most NRG Solar customers fall in love with the app and say it has a positive effect on their power use behaviour.

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Solar battery Adelaide case study: Summers family

The Summers family in Adelaide’s Aberfoyle Park has Tesla Powerwall attached to a 7.4 kW rooftop solar system. In the evenings, they have two adults and two children at home, using the usual array of lights and appliances.

Jane Summers says, “I love that I can see how much power we’re using with the monitoring app. I can see when we have a surplus of solar generation and when is the best time to operate, say, the dishwasher or washing machine. It’s definitely had a positive impact on our behaviour.”

Tesla Powerwall is charged to its 13.5 kWh capacity by the end of the day. On the average night, they draw around 8-10kWh of stored power. All of that is clean, green solar energy.

Jane says, “Before we added the battery our power bills were manageable thanks to rooftop solar. But adding the Powerwall has increased our self-sufficiency to around 95 percent. It’s a nice feeling to know that the grid only has to supply 5 percent of our power needs.”

Find out how energy independent you could become by talking with an NRG Solar consultant.

What is the difference between on-grid and off-grid solar?

We often get asked which is better: on or off-grid solar? In fact, very few homes are truly off-grid, meaning they rely solely on self-generated power and energy storage. A true off-grid scenario is more likely to occur in remote locations where network power isn’t available and almost always includes a backup petrol or diesel generator.

For remote customers, we would be pleased to help design an off-grid solar solution for your home or business.

Energy independence

When most people refer to “going off the grid” they’re talking about a desire to become more energy independent. Their property will remain connected to the retail power network, but the aim is to replace electricity from the grid with as much solar power as possible.

This is certainly the most cost effective way to simultaneously reduce your retail electricity bills and minimise your carbon footprint.

Average solar self-sufficiency of 96%

In fact, with solar combined with battery storage, on average we help NRG Solar customers to achieve a whopping 96% power self-sufficiency.

In many instances, our customers totally eliminate their power bills.

To find out how much you could save, book a free on-site consultation with an NRG Solar expert.

Can a solar battery power my home in a blackout?

As well as power bill reductions, energy security—or blackout protection—is one of the leading reasons Adelaide home and business owners choose to install solar battery storage.

In blackout conditions, they can be assured that essential appliances, machinery, lights, telephone, security systems, internet, or other critical circuits continue working.

For blackout conditions, your battery system can be programmed to run limited circuits. The idea is to avoid large loads from power-hungry appliances, such as ovens and ducted air-conditioners, in favour of keeping lights, refrigerators, TV and internet functioning as usual.

In an extended blackout, some battery systems allow the solar panels to recharge the battery while simultaneously drawing electricity to power essential circuits.

Working with an NRG Solar consultant is the best way to design a blackout protection system that meets your needs.

Read more
Tesla Powerwall Solar battery system

How to compare solar battery quotes

The first rule of getting a solar battery quote is to approach it as an investment. That means talking with a trusted, reputable solar expert.

The second rule is to get familiar with solar battery language. There are some important differences between battery systems.

The third rule is to never buy a battery based on price alone. But first...

How do you recognise a reputable solar company?

  • They have longevity in the solar industry
  • They have good reviews and lots of referral customers
  • They use recognised, quality products
  • They do on-site assessments and quoting
  • They have local people on the ground and a physical office in Adelaide
  • They can accurately quantify your payback period and return on investment

Why an on-site assessment matters

Based on our long experience repairing Adelaide’s orphaned solar systems, we know that the most unhappy customers are usually those who bought a system over the phone or got hooked into a promotion for a system that was not properly tailored to their needs.

We don’t want that to happen to you or anybody else.

Aerial images are a helpful tool for assessing how many solar panels can be fitted on a roof, but provide no help in determining what’s inside your meter box, how to neatly and safely run cables, planning for blackout circuits, how to safely work at the property, and so on.

An on-site inspection is the only reliable way to design a turnkey solution, to provide a fixed price, ‘no surprises’ quote and for your installation process to run without a hitch.

Read more about our on-site quoting process and why it matters.

What’s the difference between battery capacity and discharge capacity?

When it comes to comparing solar battery brands and systems, there are a number of important differences. We would be pleased to sit down with you and explain how the different systems work and what to look for.

But for the sake of education, we would like to briefly explain here the difference between battery capacity and discharge capacity.

Battery capacity is how much energy can be stored in the battery. It’s usually expressed in kilowatt-hours (kWh).

Discharge capacity describes how much stored energy is usable.

For example, a 10 kWh battery with 90% discharge capacity, will provide 9 kWh of usable energy. By comparison, Tesla Powerwall has 100% discharge capacity.

That extra usable capacity can have a big impact on your power savings over time and dramatically reduce your payback period.

Why should you never buy a battery based on price alone?

It often doesn’t take long for a cheap battery to become an expensive one. This is because the money you save upfront may be quickly eclipsed by money you lose down the track.

An undersized battery, for example, is easy to get overworked which means it will wear out more quickly. Focus instead on comparing features, performance and support:

  • What is the battery’s storage capacity?
  • What is the battery’s depth of discharge?
  • How does the battery work in a blackout?
  • What is the warranty on the battery, parts and labour?
  • Who is going to install the system?
  • If I need help or technical support, who will provide it?

We’ve done the product testing so you don’t have to.

When you get a solar battery quote from NRG Solar, you know you’re getting a turnkey, tailored solution based on quality products we trust.

With NRG Solar, you get:

  • Fixed price, on-site quoting
  • Detailed savings and payback projections
  • Quality solar products
  • Installation using quality fixings performed by certified solar electricians
  • Fully warrantied parts and workmanship
  • Dedicated account manager to coordinate your project from start to finish
  • We do all the paperwork
  • Local after-sales service, with a physical Adelaide headquarters
  • Reputation for quality and trust (more than 30% of our customers are referred by other customers)

Contact us to speak with an NRG Solar battery expert about a tailored energy solution for your home or business.


Recent battery installs

There’s lots of reasons why you could be left with scratching your head at what went wrong. From companies who have gone out of business, through to installations that were just never met quality or safety standards.

over 3,000+ SOLAR SYSTEMS
NRG solar 5 star reviews in adelaide
Client testimonials for solar energy
NRG solar 5 star reviews in adelaide
Paul Reynolds - Flagstaff Hill
Enphase Battery

In 2019 NRG installed 4 Enphase batteries; I already had 4, and wanted to expand. Michael Summers was my main contact, and was friendly, efficient and got me a fantastic deal! The installer was a chap called Jarrad, and I was impressed at their professionalism during the installation.

Upshot is: if you are after solar and/or batteries, speak to NRG for a quality job at a good price!

Client testimonials for solar energy
NRG solar 5 star reviews in adelaide
PIETER JACOBS - bordertown
5kW SYSTEM + tesla powerwall

My experience with NRG Solar was fantastic. From the excellent quote they gave me for my home battery system, to replies to all my queries, no matter how insignificant.
I spoke and dealt with a number of staff at NRG and, without fail, they were friendly and knowledgeable.  Everything happened at the times and dates they said it would .
The actual installation went smoothly. The technicians were there on time  and  the system was explained to me before they left . It has worked well since then.

Client testimonials for solar energy
NRG solar 5 star reviews in adelaide
adam berresford - belair
tesla powerwall

Had a great experience with NRG Solar. They installed Tesla Powerwall and the guys right from the beginning with Michael and Ellen, right down to the sparkies Alex and Jarrad, were brilliant.

What rebates and finance options are available?

Affordable Solutions- your finance and rebate options

Tesla Energy Plan

Tesla offer additional savings of Grid Credits, flexible Time of Use rates to reduce your energy bill and an extended 5 year warranty when you join the Tesla Energy Plan (TEP). Ask your NRG Solar consultant about the TEP bundle.

Solar Payment Plans

NRG Solar offer our customers an soalr payment plans to pay for solar and or battery solutions.

Plenti and Green Loans

Plenti is the South Australian Government approved lender for solar and battery. Their green loan interest rates start at 6.99% p.a. Plenti provides unsecured loans of up to $50,000 for a period of 1 to 7 years, paid monthly.

There are a number of lenders who offer green loans to finance your solar and battery needs. Green loans often have lower interest rates as an incentive for consumers to make these ‘green’ purchases. Commbank green loans are available for Commonwealth Bank customers who have an eligible Commbank home loan or investment home loan.

For more information about financing options check out our blog here.

Solar Feed-in Tariffs (FiT)

Payments you receive for solar power you feed into the grid is based on the Feed-in Tariff or FiT.

FiT is also known in South Australia as Voluntary Retailer Contributions. Feed-in tariffs are deemed ‘voluntary’ in SA because energy retailers here are not obliged to buy exported solar power. But the good news is that most do.

The current solar FiT rate in SA ranges from around 5 to 16 cents per kilowatt-hour (kWh). Compare this with the cost of buying electricity from the grid at 35 to 81 cents per kWh. You can quickly see why storing and using your own surplus solar power has big financial benefits!

In recent years, feed-in tariffs have been in decline or in some cases, have been phased out altogether by energy retailers. We consider the feed-in tariff a ‘nice to have’ because we know that the big savings with solar are in self–consumption. This is the power you generate with your panels and use throughout the day – what you don’t see on your power bill.   

Consumption monitoring, which is available with quality, modern solar, helps you understand how much energy you’re producing and using. The way to save more is to increase your daytime consumption while the sun is shining.  If  you are producing more power than you can use, it makes sense to consider storing it and using it at night instead of buying it back it at a much higher rate.  If you already have solar, and your power bills are still high ,it could be time review your existing system. Is it time to upgrade to a more efficient system or add battery storage?

Your NRG Solar consultant would be pleased to show you how to maximise your solar investment.