Backup Load vs Full House Backup: What You Need to Know

August 5, 2025

We’ve had a lot of people asking us, “What exactly is backup power?” So let’s break it down clearly — especially if you're considering a solar battery system with blackout protection.


Most energy storage inverters (like the ones we use at Aussie Solar Batteries) have two output ports:


Grid port – connects to your main switchboard, just like any standard solar system.

Backup port – connects to selected "essential" circuits you want to keep running during a blackout (e.g. lights, fridge, Wi-Fi, etc.).


Now, how your system behaves in a blackout depends on how your solar panels are connected.



AC-Coupled vs DC-Coupled: What’s the Difference?


If you keep your original grid-tied PV inverter, your setup is AC-coupled. Here’s what that means:


  • When the grid goes down, your solar panels stop working.
  • The backup port relies only on battery power.
  • Once the battery runs out, everything shuts off.


On the other hand, if you remove the grid-tied inverter and connect your solar panels directly to the energy storage inverter, that’s a DC-coupled system. This gives you:


  • Continuous solar generation even during a blackout
  • Power to both your battery and backup loads
  • A system that acts more like an off-grid setup when needed


In short: DC-coupled = more resilience.



UPS vs EPS Modes: Seamless or Not?


Let’s quickly touch on something else people ask: the difference between UPS and EPS.


  • UPS (Uninterruptible Power Supply): If the grid goes down, your backup loads keep running without any interruption. It’s instant and seamless — like nothing happened.
  • EPS (Emergency Power Supply): There’s a small delay (a few seconds) during switchover. Your backup loads will turn off briefly, then restart.

Some Each Energy inverter models offer both modes (see diagram), depending on the internal relay configuration.



Why Full-Home Backup Isn’t Always Worth It in Australia


Here’s where things get technical and expensive.


Since May 1, 2023, Australian standards no longer allow the use of RCD-type AC switches for backup systems. You now need RCBO switches on every single circuit if you want to do a full-house backup.


That means:


  • Every breaker in your switchboard needs replacing
  • Costs go up — significantly — for materials and labour
  • Electricians need to rewire and test everything to meet code


So what do most people do instead?


They go with partial backup — usually just 1 or 2 essential circuits (e.g. lighting, fridge, internet) connected to the backup port. It’s far more cost-effective and still keeps you running through outages.

“Can I Bypass This with EPS or a Gateway?”


Some folks claim you don’t need to replace all switches if you’re using EPS mode or a gateway. And yes, technically, some systems can get around full RCBO upgrades in theory.

But here’s the reality:


A licensed electrician we work with was recently audited and forced to replace every breaker on several jobs — all because he installed full-home backup systems without using RCBOs, even with a gateway.


That’s why we always say: Stick to the standards. Do it right. It saves you trouble (and fines) later.



Why People Trust Aussie Solar Batteries


Simple. We don’t cut corners. Everything we write is backed by real standards, real experience, and what actually works in Australian homes.


If you're thinking about backup power, make sure you're getting real answers — not shortcuts that could cost you more later.

Why You Should Install a 30–50kWh Solar Battery (And Not Settle for Less)

August 5, 2025
Thinking about a solar battery? Don’t make the rookie mistake of going too small. Right now, thanks to a massive new federal rebate, everyday households can install premium 30–50kWh batteries (the kind that used to be reserved for off-grid farms and big estates) for as little as $5,499. But here’s the thing: you only get one shot at claiming the rebate. And that means choosing the right battery size isn’t just a technical decision, it’s a financial one. Go too small, and you leave thousands in government funding on the table. Go smart, and you set yourself up for maximum savings, longer battery life, and faster payback. Here’s why bigger is better and why now is the moment to act. 1. Get the Full Rebate. Once. The Australian Government is offering a one-time home battery rebate — worth up to $16,800. But here’s the catch: ✅ It’s only available once per household ✅ The rebate scales with battery size So if you go small, you leave thousands on the table. But if you go big — 30 to 50kWh — you unlock the maximum rebate and only pay 25–30% of the true cost. That means you pay just $5,499–$6,500 installed for a system worth over $20,000. 👉 Bigger battery = Bigger rebate. Use it wisely. 2. Plug Into Grid Perks with ZEROHERO We’ve partnered with GloBird Energy’s ZEROHERO plan, giving battery owners three money-saving advantages: 🔌 Free Charging: 11am–2pm, charge your battery from the grid — for free. 💰 Get Paid for Nothing: 6pm–8pm, don’t draw power, and get $1 credit per day. ⚡ Export Bonus: 6pm–8pm, send your stored energy to the grid and earn 15c/kWh. It’s not just about storing solar. It’s about turning your battery into a smart, money-making asset. 🔗 Learn more about ZEROHERO 3. ROI in Under 2 Years Let’s talk return on investment. If you cycle 20kWh per day, and the difference between your feed-in tariff and electricity cost is 40 cents, you're already saving $8 per day. That’s nearly $3,000 per year — and that’s before factoring in the ZEROHERO benefits. 👉 At that rate, your battery pays for itself in less than two years. 4. Bigger Battery = Longer Life Here’s what most installers won’t tell you: Batteries degrade faster when they’re constantly drained to the bottom. But with a 50kWh battery, you only cycle part of the capacity (say 20–30kWh overnight). That means the battery never fully empties, reducing stress and extending its life. At 70% depth of discharge (DoD): over 8,500 cycles = up to 23 years lifespan At 95% DoD: closer to 1,000 cycles = just 3 years 👉 A bigger battery doesn’t just store more power — it lasts longer too. The Bottom Line ✔️ One rebate. Use it on the biggest battery you can. ✔️ Fast payback (under 2 years) + daily savings ✔️ Smart grid plan = free charging, bonus payments, and export income ✔️ Longer life = better value, year after year Don’t think small. Think smart. Install once. Save for decades.

July 25 Energy Storage Update: How Long Will Australia’s $2.3 Billion Battery Subsidy Last?

July 25, 2025
Since we published our post on July 19 about the Australian Government’s $2.3 billion home battery subsidy, it’s been widely shared across media channels. So here’s a fresh update based on this week’s installation data and STC application activity. 📊 STC Volume and Installations Update On July 19, 1.44 million STCs were submitted — covering 8,918 installations. Some readers asked whether the monthly total might reach 3 million STCs, based on the daily rate. Now, we can answer that with confidence. As of the night of July 25, the total has reached 2.248 million STCs, across 13,877 jobs. With 4 days remaining in July, we’re on track to hit the 3 million mark — confirming our projection from last week. ⚡️ System Size Trends and What’s Limiting Them Average STCs per installation: 162 This suggests the average system size remains around 20kWh The current constraint is not demand, but battery inventory and inverter limitations — particularly in systems that don’t support flexible series/parallel expansion. We expect this to shift. Based on upcoming stock arrivals, the average system size should increase to 25kWh or more in August. 📅 How Long Will the $2.3 Billion Last? Let’s do the math. If the average system size stays at 25kWh, the $2.3 billion subsidy can support around 236,000 installations. Based on manufacturer shipment forecasts, we expect 5 million or more STCs to be claimed across August and September. By October, demand will likely remain strong, but inventory will start catching up to demand. At the government’s fixed acquisition price of $40 per STC, and a total allowance of 57.5 million STCs, the full $2.3 billion in funding will likely be exhausted by April 1, 2026. ⚠️ In short: this isn’t a forever subsidy. It’s limited, and the clock is ticking. 🧰 Installer Capacity Is Not a Bottleneck The current number of licensed battery installers across Australia appears to be sufficient to meet installation demand — capacity, not labour, is the limiting factor for now. 🔄 “Aren’t Batteries Just Going to Get Cheaper?” We’ve heard this a few times: “Solar panels got cheaper over time — batteries will too.” But here’s where the battery subsidy differs fundamentally from the solar one: 🌞 Solar STC Scheme Still active STCs are purchased by electricity retailers, who must surrender them to offset non-renewable sales Based on quarterly market rules, with no fixed end Works more like a carbon trading system 🔋 Battery Rebate Scheme Funded directly by the federal government (not energy retailers) Capped at $2.3 billion AUD Once that budget is used, it’s over — no extension, no ongoing market pricing ✅ Key Takeaways: Battery rebates are real, generous — and limited We're tracking toward 3 million STCs this July alone Based on current trends, the scheme may run until early 2026, but strong demand could shorten that Now is the best time to install a larger system (30–50kWh) to maximise your rebate before supply stabilises and subsidy demand outpaces funding If you're still sitting on the fence, now you have the facts. Use the rebate while it lasts — because when it’s gone, it’s gone.