Smart Energy Automation

The Solar Sponge & Smart Energy Hacks

May 04, 20252 min read

The Solar Sponge & Smart Energy Hacks Every Homeowner Should Know

How Automation and Tariff Timing Can Supercharge Your Battery Savings


Your solar battery is powerful. But pair it with smart automation—and it becomes unstoppable.

Here’s why: Australia's energy market is evolving fast. Some electricity providers now offer dirt-cheap daytime tariffs (even down to 1–2¢/kWh) to soak up excess grid power.

This is known as the “solar sponge” period—and if you know how to use it, you can charge your battery cheaply from the grid, then use that energy later instead of buying peak power.

This isn’t just “saving with solar”—it’s beating the market with smart energy tech.


🧠 What Is the “Solar Sponge” Tariff?

During the middle of the day, especially in states like SA and VIC, there's often too much solar energy flooding the grid.

To balance the system, energy retailers are offering super low daytime tariffs to encourage usage:

  • 10am–3pm: Grid power as low as 2–5¢/kWh

  • Evening (peak): Grid power up to 40¢/kWh

If your battery can charge during the sponge, and discharge during the peak, you can save big—even if there’s no sun.


⚙️ Smart Energy Hacks (You Can Use Today)

  1. Schedule Loads for Daytime

    • Run dishwashers, hot water, EV charging between 10am–3pm

    • Use smart plugs, timers, or automation

  2. Enable Grid-Charging If Available

    • Not all systems allow this—but if yours does, set your battery to “soak” grid power during sponge hours

  3. Reserve Battery for Peak Rates

    • Some batteries (like Tesla Powerwall) let you reserve discharge for evening peak hours

  4. Use Smart Controllers

    • Tools like the Jousto Energy Hub automate all this, responding to live tariff data + solar forecasts


📈 How Much Can You Save?

If your battery stores 10kWh and you charge it at 5¢/kWh, you spend:

  • 💸 $0.50 total

If you don’t use sponge tariffs and instead draw from the grid at 40¢/kWh:

  • 💸 $4.00 total

👉 That’s a saving of $3.50/day or $1,200+ per year—just by charging smarter.


🚀 Automation = Less Thinking, More Saving

Manual control is great. But automating it is better.

That’s why systems like the Jousto Energy Hub are built to:

  • Detect sponge windows automatically

  • Charge from solar or grid based on value

  • Discharge to avoid peak prices

  • Learn your habits & optimise over time

The result? You always use the cheapest available energy—without needing to micromanage anything.


✅ Ready to Upgrade Your Energy IQ?

Denny Honen is a 20yr Renewable Energy Veteran. Denny is an Accredited solar and battery design engineer, and home energy auditor.

Denny Honen

Denny Honen is a 20yr Renewable Energy Veteran. Denny is an Accredited solar and battery design engineer, and home energy auditor.

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