Difference between Alternating Current (AC) vs. Direct Current (DC)

Understanding the difference between alternating current (AC) and direct current (DC) is easier than you might think. We actually made an article around this if you'd like to know more.

Essentially, both AC and DC refer to how the current flows in an electrical current. DC flows in one direction and is used in battery storage, where AC is dynamic and switches directions which is used in your home in power outlets etc.

If you own a solar system, that will be generating a direct current (DC), which is then converted by the inverter to alternating current (AC) to be used by home appliances.

What does AC-coupling and DC-coupling mean?

AC and DC-coupling refers to where and how the battery is connected to your solar system. 'Coupling' is another word for connected. AC-'connected' battery storage.

For example, a DC-coupled system is connected to the inverter directly which inverts the energy for it, whereas AC-coupled batteries are independent and can inverter its own energy.

Depending on your property's existing requirements, budget, and goals, installers may opt for an AC-coupled or DC-coupled to best suit your home or business.

Are AC or DC-Coupled Batteries Better for Off-Grid Solar?

For off-grid properties, DC-coupled battery storage is chosen because of seamless integration with off-grid solar inverters like Selectronic SP PRO's, which manages both solar and battery in the one unit.

Whilst it's not a dealbreaker, knowing you're getting the absolute most efficiency out of your solar system is always ideal.

Are AC or DC-coupled Battery Systems Better?

Determining on whether an AC-coupled or DC-coupled battery will come down to your unique situation and requirements

As both AC-coupled and DC-coupled batteries are designed for different purposes, there isn't a better option for all homes and businesses.

For homes with existing solar, it may be more cost-effective to retrofit an AC-coupled battery to your solar system.

For homes getting a new solar system, a DC-coupled system might make more sense for longevity and future compatibility.

If you’re looking at getting a battery for your property and are unsure whether an AC or DC-coupled battery would be better, we offer free quoting to help people like you get transparent quoting and consultation.

Are AC or DC-Coupled Batteries more Expensive?

Both AC and DC-coupled batteries will have their own unique costs including installation labour requirements desired brands and models, capacities, as well as rectification and additional components required.

Each property will have its own set of requirements which indicate varied costs of installation an AC and DC-coupled battery system.

The good news is that you can get free quoting, as well as free consultation and proposals to help you find the best solution possible.

What’s the purpose of a Battery Inverter?

AC-coupled batteries like Tesla Powerwall 2 have their own built-in solar inverter to convert between AC and DC on its own.

Because the battery storage is not reliant on the inverter, the unit must be able to convert its own energy to be used for storage of home consumption.

Newer battery storage like Tesla Powerwall 3 offer both AC and DC-coupling solutions to enable a wide variety of flexibility in solar and battery configurations.

What are Hybrid / 'Battery-ready' Inverters?

Hybrid Inverters, otherwise known as ‘battery-ready inverters’, are designed for controlling both traditional solar DC and AC inversion and battery storage inversion in the one unit.

With the ability to operate in both on and off-grid situations, a hybrid inverter is capable of seamless transitioning from solar/grid energy to stored battery energy.

Whilst hybrid inverters have fewer compatible battery options, they are generally preferred for backup energy solutions for regular grid outage prone areas due to their seamless transitioning and high energy efficiency.

Difference Between Hybrid vs. Grid-Tied Solar Inverters

Deciding whether to get a traditional grid-tied inverter, or a battery-ready hybrid inverter, will depend on a few factors like budget, energy requirements, and goals.

If you’re looking at getting battery storage along with your solar system installation or a little after, a hybrid inverter might be the option to choose for a reduction in system complexity.

For those who are just looking into solar energy and are not interested in battery storage for the near future, a grid-tied inverter will do the job. Traditional inverters are generally cheaper than their battery-ready counterparts.