Why? you may ask...
Congratulations on installing your iStore Solar Battery! While solar power is the primary way to charge your battery, leveraging grid power during specific times can boost your savings even further. By switching to a Time-Of-Use (TOU) electricity plan, you can take advantage of cheap Off-Peak and Super-Off-Peak tariffs.
There are two key benefits to incorporating grid power into your charging strategy:
Extended Savings Through the Night: If your battery’s charge doesn’t last the entire night, you can at least continue saving using cheap overnight Off-Peak grid power.
Reliable Charging on Cloudy Days: On days with limited sunlight, your solar panels may not generate enough excess power to fully charge the battery. By scheduling AC charging during the ‘Super Off-Peak’ period, you can top-up your battery affordably, ensuring it reaches 100% charge every day, regardless of the weather.
Setting up an automatic AC charging schedule for your iStore Battery during these cost-effective windows guarantees energy reliability and savings.
synergy TIME-OF-USE PLANS AVAILABLE
Positive Energy Solutions is a Perth based company, where the majority of residents are on the Synergy ‘Home A1’ plan which offers a flat tariff of 32.37 cents/kWh.
However, Synergy also offers some TOU plans to encourage & discourage grid power usage during certain times.
Firstly, the Synergy ‘MIDDAY SAVER‘ plan.
https://www.synergy.net.au/Your-home/Energy-plans/Midday-Saver
- Super Off-Peak (9am to 3pm) = only 8.61 cents/kWh.
- Peak (3pm to 9pm) = 53.84 cents/kWh. Ouch! But don’t worry, you have a Solar & Battery system to provide power during this expensive window.
- Off-Peak (9pm to 9am) = 23.69 cents/kWh.
Or for those with an Electric Vehicle or Plug-in Hybrid, the Synergy ‘EV ADD ON‘ plan is similar to the Midday Saver plan, but with an even cheaper overnight off-peak rate.
https://www.synergy.net.au/Your-home/Energy-plans/Electric-Vehicle-Add-On
- Super Off-Peak (9am to 3pm) = 8.61 cents/kWh.
- Peak (3pm to 9pm) = 53.84 cents/kWh.
- Off-Peak (9pm to 11pm / 6am to 9am) = 23.69 cents/kWh.
- Overnight (11pm to 6am) = 19.38 cents/kWh.
*Note: These Synergy TOU plans have a higher daily Supply Charge of 129.22 cents per day. In comparison, the standard Synergy ‘Home A1’ Supply Charge is 116.05 cents per day. This is a $48 per year difference.
A real-world example
Our customer, Karl in Dwellingup, has high daytime power usage. As a result, his 15kWh iStore Battery wasn’t always reaching 100% charge every day. Especially not on cloudy days. And without a fully charged battery, it became depleted in the evening sooner rather than later.
After taking our advice and switching to the Synergy Midday Saver plan, Karl set an automatic daily AC Charging schedule from midday to 3pm. At 5kW max charging speed, the 15kWh battery can be fully charged within this 3 hour window, even if starting at 0%.
Below is one example showing Karl’s high daytime power usage on a partially cloudy day. Due to limited excess solar power, the battery had only reach 35% State-of-Charge (SOC) by midday.
Fortunately, AC Charging began and the battery still reached 100% charge before 3pm. And with a full charge, Karl’s battery was able to last until 11pm, after which he continued to achieve savings on the overnight Off-Peak rate. Happy days!
quick guide: SETTING AN AC CHARGING SCHEDULE
After you have switched to a TOU electricity plan, log in to the iStore online monitoring portal.
From your ‘Site Overview’ dashboard, click the ‘Storage System’ (battery) widget on the Energy Flow Diagram.
- Click the ‘Parameter Setting‘ tab.
- Set the Maximum Charge Power
- Set the Maximum Discharge Power
Note: The maximum limits will be shown in the Reference value. Eg. 5000
- Charge from AC = Enable
- Working Mode = TOU
- Add your Charge schedule Start time, End time & Days to repeat the schedule.
- Add your Discharge schedules for all other times outside of the Charge schedule window
Note: Charge & Discharge times cannot overlap
- Redundant PV energy priority = Charge preference
Note: this will allow the battery to still charge with excess solar power during Discharge windows
- Click ‘Issue‘
- Click ‘Confirm‘
If you are a customer of Positive Energy and would like assistance setting these schedules, please reach out to your Positive Energy Consultant who will be happy to help.
NEED A BATTERY EXPANSION?
If your battery is often not lasting the entire night, you may want to consider a Battery Expansion. Especially if your battery isn’t lasting past 9pm.
While 15kWh is the maximum iStore battery stack size. More energy storage can be achieved with multiple battery stacks.
- Single-phase 5kW, 6kW & 10kW iStore inverters can have up to 30kWh (2 x battery stacks)
- Three-phase 5kW & 6kW iStore inverters can also have up to 30kWh
- Three-phase 10kW, 15kW & 25kW inverters can have up to 60kWh (4 x battery stacks)
