If you’re considering a solar battery under the new Battery Booster Program (also known as the Cheaper Home Batteries Scheme), here’s something most homeowners miss: your hot water system has a huge impact on what battery size you actually need.
At RJT Plumbing & Gas, we’ve helped hundreds of Queensland families install and upgrade their hot water systems, and one thing we see constantly is people getting talked into batteries that are far too big for their real usage. The result is wasted money and under-performing solar systems.
The truth is, the right hot water system should come before the battery.
1. Why Your Hot Water System Matters for Solar Battery Sizing
Hot water heating is one of the biggest electricity loads in an Australian home, often 25 to 35 percent of total power consumption.
A standard electric storage system can use 4 to 8 kWh per day, depending on the household and time of year.
If you install a battery without understanding that load, you’re guessing.
A mismatch between your water system and battery capacity means you might:
- Pay for battery storage you’ll never use
- Still rely heavily on grid power at night
That’s why every smart energy upgrade starts with plumbing, not panels.
2. Bigger Batteries Aren’t Always Better
Since the Battery Booster Program launched in mid-2025, Queenslanders have installed record numbers of home batteries.
Government data shows average battery sizes have jumped from 12 kWh to almost 19 kWh in just a few months, mainly because larger batteries attract larger rebates.
But here’s the catch.
If your home doesn’t generate or use enough power to fill and drain that capacity daily, your return on investment drops fast. You’re essentially paying for storage you never use.
Choosing the right-sized system means matching:
- Your daily energy use
- Your solar generation hours
- When your hot water system draws power
That’s the difference between a system that just works and one that pays for itself.
3. How RJT Helps You Choose the Ideal Hot Water System
We’re not here to sell you a product. We’re here to give you clarity.
RJT Plumbing & Gas has more than 400 five-star reviews from Brisbane and Moreton Bay homeowners who trust us for honest, practical advice that often saves them money.
When we assess your setup, we look at:
- How many people live in your home
- Your daily hot water usage patterns
- Whether you’re on gas, electric, or heat pump
- When your system heats (day vs night)
- Your solar generation and battery potential
From there, we recommend the best fit for both your family and your long-term energy plan.
A simple change, like switching to a heat pump hot water system, can reduce your water heating costs by up to 70 percent, often making a smaller and cheaper battery perfectly adequate.
4. Real Advice. Real Savings.
We’ve seen countless homeowners spend more than they needed to on energy upgrades.
That’s why our team focuses on real-world performance, not sales hype.
Whether it’s sticking with a reliable gas system, upgrading to a heat pump, or planning for future solar storage, we’ll help you make an informed, cost-effective choice that works for the long haul.
If you’re planning a battery or hot water upgrade, talk to RJT first and make sure your system is working with your solar, not against it.
RJT Plumbing & Gas is a trusted plumber servicing North Lakes and surrounding suburbs. With 400+ verified reviews and a 5 star rating, it’s clear that our customers love us and you will too.
Get practical advice before you invest in your battery upgrade.
Call us today or book online.
