5 Common Myths About Solar Batteries Busted

Energy storage is an active field of investigation worldwide; progress has been made in the last couple of decades, but we’re all still in nappies when it comes to electricity storage.

However, innovation leads to new technologies and opportunities that create new markets for the most common way of energy storage: batteries.

Australia, being one of the most promising environments and markets for solar PV, is also on edge as an interesting market for battery storage.

In 2017 a massive deployment of distributed solar PV with battery storage took place in several states across the country, especially in New South Wales, Victoria and Queensland.

Such deployment is related to the reduction in battery prices but is also on the media news regarding the Tesla’s 100 MW project on South Australia, so yes, Elon Musk takes part in the scenery again.

Instyle Solar Battery Myths Australian Energy Council Report

Here you can take a look at how energy storage installation is growing across Australia:

5 Common Myths About Solar Batteries Busted Battery Growth

With this accelerated development and the positive projections regarding battery prices in the next several years, it’s logical to think that the tendency will keep increasing over time.

That is why it’s crucial to dismiss some important misconceptions that surround the solar energy storage topic to help you understand the real concept of solar battery!

Let’s examine some of those myths and bust them out!

Myth 1. Grid-tied with battery backup systems are ALWAYS beneficial for your budget.

The whole concept sounds good: with the rise of electricity prices all over the country, the most brilliant thing to do is to use the energy produced by the solar panels and store excess in solar batteries instead of selling it to the grid through a simple grid-tied system, just to obtain half of the value of the kWh under the feed-in tariffs.

Later, at night, it will allow you to use stored energy instead of using electricity from the grid, which will be at its peak price due to higher demands on the power grid.

This is how you think you’ll profit every night and in the long term, that will mean savings on electricity!

That sounds really wonderful, but the truth is things are not that easy.

What is more important is to point out that batteries do not work on their own to charge and discharge themselves!

You’ll need a series of electronic devices to keep your batteries in good shape and to make sure the energy management flows between the generation (panels) and the loads.

All of these electronics will increase the overall cost of the system - capital costs that must be included if you consider installing a battery backup system at home.

In other words, instead of having a simple grid-tied system with merely the panels and a simple inverter, you’ll have to choose a grid-tied with battery backup system (or stand-alone system) that includes charge controllers and more complex inverter chargers / hybrid inverters with a lot of functionalities that you may not end up using.

Not to mention the additional protection devices (like fuses or DC breakers) and high gauge wires that will be needed to connect the batteries to the control systems.

And speaking of control, you will also need an energy management system that will allow you to set charge and discharge times for the batteries and the overall interaction of the system with the grid.

Moreover, you should keep in mind the electricity rates of your energy retailer. The kWh stored in the batteries must beat the peak price of electricity every night in order to be profitable in the long term.

Here is an example of the electricity prices in Australia. As you can see, they are high. Actually, Australian households are paying some of the highest electricity rates in the world.

Instyle Solar Battery Myths Electricity Retail Prices

So be careful and do the math first. Simply put, there is no completely reliable way to ensure that your Lithium-ion battery system will pay for itself before the warranty on the batteries ends.

There are a whole set of variables from the different battery installation sizes, passing through electricity prices, solar resources in different cities and feed-in tariffs, that cannot be accurately measured in a general context to provide a big YES.

Talk to your solar expert first.

Myth 2. Any battery system can be connected to my solar PV and provide me with electricity during blackouts.

Blackouts are an excellent reason for going solar and having your system backed up with batteries.

If you look at the general context of blackouts in Australia, you’ll see that the system is not as reliable as it used to be some years ago.

The reasons behind that are related to the limited frequency response of the power grid to demand changes, as well as a whole analysis of power systems stuff that we will not explain in this article (but you’re more than encouraged to take a look at the explanation here).

As mentioned above, battery banks need to include energy management systems, charge controllers and inverters. The thing is, all systems can provide you with protection against blackouts, right? NO!

As an example, let’s take a look at the most famous microinverter company in the world, Enphase.

With the IQ 7 system, the company offers the best solution on the market for microinverter installations.

Enphase also offers an energy storage solution with their own integrated solar battery and inverter in conjunction with the system.

You might think that you can hire an Enphase solar contractor for backup purposes, but the question is - should you?

If you’re aiming to add batteries to protect yourself against blackouts, then you cannot use an Enphase battery system because they do not work without the frequency from the grid.

Due to the nature of the system, it is designed to be disconnected in the case of a grid failure.

This is a limitation of Enphase systems to the IQ7 version (latest). I think the IQ8 version would solve this problem, but it is still not on the market.

Myth 3. Fuel generator Vs. batteries for blackouts? Always best to buy fuel generators!

This is the common assumption led by capital costs of both products.

Undoubtedly, fuel generators are still much cheaper than batteries, especially if they are Lithium-ion batteries.

However, if we take a broader look at the scene, we should also consider the operation of the system.

The fossil generator needs fuel to run, which means you need to store fuel in your house or shed, with all the logistics, payments, dangers and uncertainty (on fuel prices and availability of the fuel) that brings.

Despite the recent reliability issues of the system, the grid is still reliable over the course of the year.

So most of the time, the fuel generator would be turned off. But your batteries won’t be!

They will be working perfectly to make energy management of the system give you the greatest economic advantage by storing the energy produced in the morning and using it at night. This saves you money every day!

It doesn’t matter if one month the electricity rate was not as high as usual, the benefit will still be there compared to the stocked fuel generator.

Moreover, if when thinking about the capital cost of the system you’re considering the low budget, then you can lower the autonomy of the system as well. For example, it can work merely one or two hours and backup only the essential loads of the house.

After all, you must consider typical blackout events - which usually don’t last for more than an hour - to size your system. Otherwise, if you consider abnormal circumstances like the overlong blackout in South Australia in 2016, then your system would be unthinkable.

Besides, if that still doesn’t work for you, you can also consider the old-school AGM lead-acid battery the capital cost of which will be much lower than Lithium-ion batteries.

Simply put, solar batteries can indeed beat fuel generators after evaluating the whole scope and can even pay for themselves in the long-term, possibly leaving you with some nice profit (depending on your location).

Myth 4. If I don’t use batteries over 3 months, I’ll still have them charged.

False!

Unfortunate as it is, any solar battery discharges at a specific rate over time, even when it’s disconnected from any load.

The rate of discharge varies depending on the battery type, manufacturer and the environmental conditions (mainly temperature) of the location where the batteries are placed.

That’s why if you are going to store your batteries for some time, you must make sure that they are kept safe in a fresh 25°C environment.

By doing so you’ll reduce the discharge as much as possible.

Also, you can set the charge controller to charge the batteries a little bit above regular charge to keep the voltage at a decent level over longer periods of time.

Myth 5. If you want a battery with your solar system, install it now! No modifications can be done later!

This is absolutely false!

Thanks to the AC-coupled system topology you can install a grid-tied system and then add a battery-based inverter that will act as an AC/DC converter to charge the batteries, and as a DC/AC converter to extract energy from the batteries.

What you must take into consideration is that not all inverters and batteries are compatible with one another, so synchronising the two of them to work simultaneously is not always easy or possible.

The reason behind the possible incompatibility is that grid-tied inverters use an impedance check mechanism to detect if the grid has failed or not.

If the impedance rises above a certain pre-established threshold, the anti-islanding mechanism of the inverter would be triggered and it will be disconnected.

Battery-based inverters typically have a higher output impedance than the impedance from the grid. If this impedance exceeds the threshold from the grid-tied inverter, it will trigger, making them incompatible.

Therefore, if you have the slightest doubt about whether or not to add batteries, choose a popular AC-coupled solution such as the Fronius-Victron Energy AC coupled system, the SMA Sunny Boy and Sunny Island AC coupled system or the Schneider Conext XW+ and Conext RL solutions.

There are more solutions available. An Instyle Solar expert can work out the best option for your specific needs.

Conclusion

We have examined some of the most remarkable myths in the Australian solar battery industry to give you an idea of what’s real and what’s not!

As an overview of the energy storage market in Australia, we have seen that the trend seems to be growing fast since 2017 and it is likely to keep going that way.

But still, prices are not always favourable in all cases as both cost and savings depend on many factors.

Therefore, the advice is to think of energy storage as a reliable way to keep your most important appliances active during a blackout, with the collateral benefit of an energy management system to save costs during times of peak electricity rates.

It is still not advisable to look at it as a “business” to gain more money, as there are many risks in the investment that no solar contractor can completely erase.

Next Step

If you want to see how much solar or battery storage could save you over the next 5 years, then take our solar saving calculator quiz below!

Or talk to an Instyle Solar expert about the best solutions for home energy storage or PV-panels.

Otherwise, head back to the solar blog to find even more great educational content.

Photo credit: Depositphotos, Australian Energy Council, Financial Review

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