Your all in one guide to buying the best solar battery storage

Best solar battery storage buying guide

If your house is equipped with a solar power system, you probably are thinking of getting storage batteries too. But how can you get the best storage solar battery? Here’s all you’ll need to make the right choice.

Usage of solar battery

With more and more people shifting to renewable sources of power, solar batteries have become quite popular. If you use your own electricity during daytime, chances are you might want to completely get rid of the grid electricity. Your reasons could be economical or environmental or simply the fact that you no longer want to rely on electricity companies.

A solar storage battery helps you with electricity even during an overcast day and at night time. All the excess power generated by your solar energy system can be stored in a storage battery.

Sending electricity to the grid will earn you feed-in tariffs, but to be honest, those aren't that generous anymore. You could save a lot more by using electricity from a solar battery as this will be cheaper per kilowatt-hour in comparison to grid electricity.

What will a solar battery cost?

The cost will largely depend on the capacity of a battery. The higher the capacity, the more you’ll need to pay for it. Below is a general range of prices for commonly used battery capacities:

• 6kWh: $4500–9600
• 10kWh: $9800–14,000
• 13kWh: $8000–18,000

This is just the battery cost. These do not include installation charges. 

Getting a battery along with a solar power system is penny-wise. This is because accommodating a battery at a later stage, especially when your solar panels are old can require a significant upgrade.

Lower range batteries will have just the battery unit included whereas a battery of a higher price range will also come with other integrated components like the built-in battery inverter etc. So, make sure to check what you're getting for the money you’re paying.

Is the investment worth it?

For most homes, a solar battery at the moment is not that economical. This is due to the fact that solar batteries are still very expensive. Most probably in a coming couple of years, when the electricity market changes, it might prove to be a more fruitful investment.

Whether getting a storage battery is a good investment or not is also dependent on your consumption. If your household has a heavy consumption of electricity then surely getting a battery will help you save lots.

Incentives and rebates

The government is doing its bit by incentivizing solar power components to encourage people to go solar. Energy trading schemes like Reposit along with STCs rebates do make batteries cost-effective for some households.

There are other state-specific schemes and loans available. For example, NSW has the Empowering Homes solar battery loan offer that you can apply for.

Rebates change every now and then, so it’s better to know more about these at the Federal Government website.

Virtual Power Plant (VPP) Programs:

These further incentivize the battery costs. Through a VPP program, you make your excess electricity accessible to a VPP operator who supplies it to the grid when there is high demand.

The VPP operator then pays you a subsidy in return. This may be in the form of a rebate, reduced electricity bills, free installation of solar panels and batteries.

Consider your feed-in tariffs:

What you also need to keep in mind is the current feed-in tariff you receive. Although the feed-in tariffs these days are not too high, it still does affect the amount you save. So, you might want to factor in the fact that while the electricity you use to charge your battery may no longer get you a feed-in tariff.

If you feel that a feed-in tariff is more profitable for you, you can think about getting a battery after a few years.

What battery specifications do you need to keep in mind?

There are a few technical aspects to consider before buying a battery for your solar power system.

The capacity of the battery:

You need to know how much energy a battery can hold. This is measured in kilowatt-hours (kWh). There is 'nominal capacity' which is the total energy that the battery can store and then there is ‘usable capacity which is the actual amount of energy that can be used after factoring in the depth of discharge.

Depth of discharge (DoD):

Batteries mostly need to hold some charge so as to avoid damage. DoD is the amount of power that can safely be used without fast-tracking the deterioration of the battery. It is described as a percentage. Different batteries can be discharged to different levels. For instance, lithium batteries could be discharged to around 80-90% of their nominal capacity, lead-acid batteries to about 50-60%, whereas flow batteries can be discharged to 100%.

Power: Measured in kilowatts, it is the amount of power a battery can deliver. The maximum power that a battery can provide at a given time is called ‘peak power’. Then there is ‘continuous power’ which is the power that the battery delivers when it has enough charge.

Efficiency: For the electricity that goes in, how much can the battery store is the efficiency of the battery. There will always be some energy loss.

Lifespan: The expected life of a battery needs to be kept in mind. You also need to consider its efficiency at the end of its life.

Ambient temperature range: You need to keep the battery in a proper temperature range. Extreme temperatures may cause harm and result in a shutdown.