The growing commercial and grid-scale use of batteries is driving improvements in energy storage technology and reducing prices. From July , the long anticipated boom in home storage will arrive as result of the Federal Government’s $2.3B Cheaper Home Battery Program. With Australia’s huge adoption of solar (4m solar properties and counting) and high energy prices, this is set to become the tipping point for up to 500, households and businesses to add storage over the next 5 years.
If you are investigating whether energy storage is right for you, this Buyers guide outlines the technology, costs, payback plus what to look for when buying a battery for your home. See our Battery storage owners guide to find how to get the most from your battery including price arbitrage opportunities, joining VPPs, cycling strategies and more.
When it comes to shopping a battery here’s what you need to know.
There’s a bunch of reasons why households choose to add energy storage. A battery enables solar owners to consume even more of the rooftop energy they generate and reduce use of more expensive grid electricity, particularly at peak times and rates. A battery can import off-peak energy from the grid when energy is cheaper as well as from solar and save it for later use.
You’ll need an inverter to rock your battery!
Not all the energy put into a battery will return.
Accessing power fast lets you run more appliances.
Lithium is the go-to technology for home batteries.
Lead Acid batteries are a cheaper and simpler technology that powered the first wave of off-grid battery storage and backup power for data-centres. Lead Acid technology is used in cars because it’s reliable and stable. However, it is much less efficient than Lithium. That’s because Lead Acid isn’t capable of as low a level of discharge and they have higher resistance compared to lithium batteries. Typically you can output around half of the batteries capacity – to protect the battery from degradation. This means you’ll need a much bigger system to get the same output.
Lead-acid was the pioneering energy storage chemistrySodium Nickel Chloride ‘SoNick’ batteries use molten salts as an electrolyte to store energy. ‘SoNick’ technology offers high energy and high power density and is claimed to retain good capacity. Plus these batteries are more environmentally friendly, without toxins. The downsides of SoNick batteries are a shorter lifespan than Lithium and a much bigger price tag.
‘SoNick’: Very safe, very reliable and very expensive.
Zinc-bromine ‘Flow’ batteries are a recent contender for home storage systems. The main advantage of these batteries is that they can be fully discharged without impacting the lifespan – giving owners access to more energy in a cycle. ‘Flow’ batteries are made with recycled and reusable components so are more sustainable than Lithium. However, they come at a price premium.If the price drops, Flow batteries could be huge.
To correctly size a battery, you need to consider;
The significant reductions to the price of storage thanks to Governments Rebates are available only once. So it can be worth considering your future energy needs and plan ahead- whether adding an EV or an uplift in energy use to enhance the comfort level of your home. Adding a bit more “headroom” now, will extend the payback period, but could offer households better long-term value for their investment.
Measure your energy use to get the battery size right
Payback periods on batteries are long. We’re talking typically over ten years. However, for situations with smaller/lower-cost batteries and where the price of peak electricity is higher, then payback periods can be lower.
The ideal situation for a shorter payback is one where peak electricity rates are higher for relatively short periods (so you need less battery storage) and where off-peak electricity is inexpensive. This is the case for those in the Ausgrid electricity network (Sydney, Newcastle) where peak rates are well above 40 cents per kWh and off-peak is below 20 cents per kWh and the peak period is 4-6 hours on weekdays only. Also, South Australia’s high electricity rates help the financial case for adding energy storage to an existing solar PV system.
Battery storage has a decade long ROI
David HileyFor a long time – if people asked me about buying battery storage purely for financial reasons the short answer was “No, not yet”. Sure, solar feed-in tariffs have been on the slide since meaning you’ll want to use more of your solar rather than export it, while grid rates jumped significantly in . The sticking point was the high price of batteries, that resulted in a payback of well over a decade.
From July , the 30% drop per kWh in storage prices due to the Cheaper Batteries Program, means adding a battery is accessible for a lot of households. Plus, when you factor in the increasing number of opportunities to monetise storage including Virtual Power Plants (VPP), Demand Response and tariff optimisation – then payback periods are well under ten years.
When you combine all the benefits of having energy storage – blackout protection, greater independence, using more of your solar or accessing off-peak rates while avoiding peak rates – then buying now can be a logical choice. It certainly was for me in June . And I wouldn’t give up having a battery and the financial and lifestyle benefits it offers.
Compare your battery options to find the best deal.
Here are the questions you’ll want to ask when you get closer to buying.
What size battery do you recommend? How long will the battery last into the evening before it runs out based on my current use? Will it cover my usage in peak periods? Would the battery be suitable in future if my energy use changed?
How much will it save me on my bills? (Use our handy ‘Add battery’ feature on the WATTever comparison for an independent validation)
What’s the forecast payback period?
Get a written quote with a breakdown on price and the components included.
Ask if it’s possible to expand the set up in the future? Could more storage be easily added?
Can the system be easily user-programmed? Or does the installer need to do this? Is it simple to monitor what the battery is doing?
Is the battery system compatible with retailer VPPs (check here) or automated battery management solutions in order to maximise your return?
Is the installer accredited? For example, Clean Energy Council (CEC) Approved Retailers are part of an industry scheme. They provide a 5-year whole of system warranty, only work with CEC accredited installers and meet the Solar Retailer industry Code of Conduct
Ask how long they have been operating for. You want to know if they’re going to be around in 2 years in case of a problem.
Is the installer accredited? Clean Energy Council (CEC) accredited installers undertake ongoing professional development and training pus commit to a code of conduct.
Check online reviews of installers and request local references. A good installer will have customers willing to share the experience.
Read online reviews of the recommended battery system and components.
Review the warranty on offer. At least 5 years on inverter and batteries. Performance warranties are very hard to claim on.
Does the battery and inverter makers have local offices? This way you could make a claim direct with the manufacturer should you ever have a problem.
Review the fine print in the contract. Especially around the warranty and support service.
Wirentech Product Page
About a decade ago, a solar battery was a remarkably premium item with very few customers - something like a $8 popcorn bucket that most of us just roll our eyes at. However, plunging prices and increasing benefits have boosted the popularity of solar batteries.
Thanks to benefits such as backup energy and resilience against blackouts, an increasing number of Kiwi homeowners are seriously considering installing a solar battery - both with or without solar panels. If you are contemplating buying a battery storage system, here are a few things to consider.
Humans learnt how to harness energy thousands of years ago, but it was just recently that we figured out how to ‘store’ energy. For a long time, heavy, bulky and somewhat ugly-looking lead-acid batteries were the most common type of batteries used for energy storage.
Fortunately, lithium-based batteries have risen as the most desired and the highest-selling battery type in recent years. Lithium batteries are significantly lighter and more efficient than older technologies. Plus, they also last longer and require little to no maintenance over their lifespan.
Among lithium-based batteries, there are two main types - the NMC chemistry (Nickel Manganese Cobalt) and the LFP chemistry (lithium iron phosphate). NMC batteries have been the most common type of lithium batteries for many years now. They have higher energy density and versatility, making them suitable for a variety of applications.
However, if you aren’t too short on space and just need to power your home, LFP batteries offer remarkable advantages over NMC - they last longer and have much better thermal resistance, meaning you won’t have to worry about fires.
Some popular examples of NMC batteries are the Tesla Powerwall 2 or the Enphase IQ battery. On the other hand, the Tesla Powerwall 3 and the BYD battery models come with LFP chemistry.
Enphase IQ Batteries
One of the key factors to consider when choosing a solar battery is its main set of technical specifications - its energy storage capacity and power rating. The energy capacity will decide how many kilowatt-hours (kWh) of energy you can store in it, while the power rating decides how much power in kilowatts (kW) you can draw from the battery at any given moment.
Most solar batteries today come with an energy storage capacity of 10-15 kWh. However, you can easily find models with higher or lower capacities. In most cases, you can increase your storage capacity by connecting multiple batteries together. Several battery models today also come with a modular design, allowing you to increase capacity by just stacking another module on top of your existing battery.
As a rule of thumb, it’s a good idea to choose a battery capacity that is similar to your daily energy requirement. If you live in an area with frequent blackouts, getting a larger battery also makes sense. As for power rating, choose a model with a continuous power output that can handle most or all of your home’s appliances - especially the power hungry ones.
Roundtrip efficiency is a somewhat fancy name for your battery’s generosity. In other words, it is the amount of energy that can be retrieved from the amount of energy that was previously stored in a battery. For example, if a battery is charged with 10 kWh of energy and it discharges to produce only 9 kWh, it has a roundtrip efficiency of 90%.
Needless to say, you should look for a model with roundtrip efficiency that’s as high as possible. The good news is that while older batteries offered disappointing efficiencies of 60-70%, modern lithium batteries offer roundtrip efficiencies of over 90%, and some models even hit the 100% mark!
Besides efficiency, there’s another percentage value that you need to look at - the depth of discharge. As the name suggests, it is the amount of energy that just remains in the battery and cannot be extracted. Think of the last few drops of juice in a box - those that you can never get out but just make slurpy noise and embarrass you around people.
Older batteries had low depths of discharge, meaning that with a 10 kWh battery, the usable capacity was just 7 or 8 kWh. Thankfully, modern batteries excel here too, regularly offering a 100% depth of discharge.
When you are spending thousands of dollars on something, you typically have two worries - how long will it really last, and what if it breaks down? Once again, lithium batteries beat older technologies by offering long lifespans of 10 or more years. Most lithium batteries even come with a notable 10-year warranty.
The only catch is that the battery’s efficiency and capacity will drop slightly over time. Thankfully, your battery manufacturer will also offer a warranty for how much degradation the machine will undergo over the decade.
Probably the most obvious item on this list is considering the pricing of your battery options. Typically, a solar battery will cost anywhere between $10,000-$15,000 with installation, but these numbers can vary widely based on size, brand, features, etc.
A more useful number would be the price per kWh, which allows for a better comparison of different models. Currently, home solar batteries cost somewhere around $-$/kWh with installation.
Although it is called a ‘solar battery’, your battery doesn’t have to charge from solar power alone. Many battery models today come with grid charging capability. While the primary goal of a solar battery is to store excess solar energy and supply it later, grid charging offers significant flexibility, especially during cloudy, rainy days when our solar panels are as unproductive as us.
Some energy retailers also offer cheap or free power at certain times of the day or week, such as Contact’s Good Nights plan which offers free electricity between 9 pm and midnight every day, or Z’s EV charging plan which offers free power from 3-6 am and half rates between 9 pm and 7 am. You can charge your battery during hours of free or cheap power and use the energy during peak hours such as mornings or evenings - effectively enjoying free power at whatever time of the day you want.
There are dozens of solar battery brands in the market today, and not all of them are equally reliable for product quality and/or customer support. Some of the brands that are highest-rated across all categories are Tesla, Enphase, Sonnen, Sungrow and BYD. Check out our battery product comparison page to compare numerous reputable solar battery brands and models.
From watches and cars to refrigerators and TVs, every commodity is becoming ‘smart’ in one way or another, which is why it would only be a surprise if batteries remain ‘dumb’. Modern batteries are a lot more than just energy storage devices. They come loaded with several sensors and other electronic stuff that make them more usable.
For instance, nearly every modern solar battery comes with Wi-Fi connectivity. You can connect your smartphone to the battery even remotely and monitor several parameters such as state of charge, solar charging power, discharging power, and more. The Tesla Powerwall can even connect to a weather station and keep an eye out for potential storms, in which case it can reduce discharging and charge fully to prepare for a possible blackout.
Solar batteries have come a long way in terms of technology, cost and features. When paired with solar panels, they offer a complete home solution - one that brings you energy independence and electricity bill savings.
However, with the huge variety of battery brands and models available today, choosing the most suitable option for your needs will take some work. It’s always a great idea to consult a reputable solar installer to calculate your required battery size and figure out what features you need. And don’t forget - we can help you get multiple free quotes from vetted solar installers.
If you want to learn more, please visit our website Storage Battery Manufacturer.