Submitted by Webmaster on Thu, 08/09/2016 - 09:15
Enphase AC Battery System

Anyone with a solar PV system will tell you, you can save money by timing your power consumption for the middle of the day, when your panels are most productive. Solar self-consumption allows you to take the electricity that your PV system has just produced and use it to power appliances in your home, like a dishwasher.

This approach is fine if you are at home during the day, but what if the majority of your power consumption occurs in the evening? That is where battery storage comes in. And let’s just say, the benefits of including battery storage in your solar PV system go far beyond the convenience of having a reliable energy supply during a neighbourhood blackout.

The perfect combination of technology and tariffs

In this case study, we feature a solar power system with Enphase AC Battery storage. Following Enphase’s modular approach to solar, this storage system can be scaled up as your needs grow by adding or removing individual battery units. Here, we focus on a system that incorporates three Enphase batteries, which each cycle twice daily.

When paired with Synergy’s ‘Smart Home Plan’, which is a Time Of Use (TOU) tariff, there are a couple of ways you can make the most of your Enphase system, each with the potential to save you money.

How do TOU tariffs work?

The Synergy Smart Home Plan TOU tariffs reward consumers with reduced electricity prices on power they consume outside peak hours. With an Enphase AC Battery system, you can take advantage of these discounted off-peak rates.

Savings of Enphase AC Battery with Synergy Smart Home Tariff
Weekday 1 0.12 x 3.3 x 26 $103.36
Weekday 2 0.4 x 3.3 x 26 $361.75
Weekend 1 0.12 x 3.3 x 104 $41.18
Weekend 2 0.18 x 3.3 x 104 $64.18
Savings Per Year $570.00
Payback for $7,000 battery 12.7 years


If we take a closer look at Synergy’s TOU tariff, you’ll notice that electricity purchased from the grid during peak periods costs about 49c/kWh, whereas electricity purchased during shoulder periods costs about 25c/kWh and electricity purchased during off-peak periods costs about 13c/kWh, which is the cheapest rate of all. Keep these rates in mind as we discuss how best to take advantage of TOU tariffs using battery storage.


This is a breakdown of how the following battery storage techniques can save you money.

Solar arbitrage makes financial sense

Through solar arbitrage, you can make the most of lower, off-peak energy prices by charging your batteries at night using electricity from the grid and storing it for use during peak times, when grid electricity is more expensive. This approach is particularly helpful during periods of bad weather when your panels aren’t generating as much energy as they normally would.

In the case of our three Enphase AC batteries, the Synergy Smart Home Plan will enable us to save $144 a year, just through arbitrage alone.

To learn more about how arbitrage works, we suggest you speak with one of our experienced solar battery experts about the best energy management option for your system.

Storing your excess solar can mean big savings

Capturing the energy your solar PV system produces for use later on, is really where battery storage makes sense. In particular, since the Enphase AC Battery system cycles twice a day, you can recharge your battery overnight, use that power during the morning, then recharge it again with energy from your panels to use at night, when electricity is most expensive to buy from the grid.

If we refer to our example, by capturing excess solar energy and using it in the evening at peak times, we’ll save and additional $425 a year.

Battery storage offers the best of all three options

The combination of self-consumption, arbitrage and capturing excess solar is an intelligent way to maximise your savings and really make the most of your battery storage. In this case study, we’ll be saving about $570 every year through arbitrage and excess solar alone, plus any addition savings that can be achieved through smart self-consumption. With a $7,000 battery system, that’s a payback period of only 12.7 years.

Speak with us for expert advice

If you’d like to find out how to incorporate these battery storage techniques in your home, contact us on 1300 73 93 55 to speak with one of our solar battery experts today.