Who’s Involved?
We followed two typical North Lakes households, each with four family members (2 adults + 2 children), using around 150 litres of hot water per day — a common volume for suburban homes.
Homeowner A – “The Harris Family” (Electric Hot Water)
“We’ve always used electric. It’s simple, we never thought much about it — until the power bills started creeping up.”
- Family of 4, two working parents with school-age kids
- Uses a standard electric storage hot water system
- Located in a 15-year-old home with no rooftop solar
- Average energy use for hot water: ~12–15 kWh/day
- Annual hot water cost: ~$790
- Noticed slow recovery in winter and occasional lukewarm showers after heavy use
- Reported noticeable spikes in electricity bills, particularly over summer and winter
Homeowner B – “The Martins” (Solar + Booster)
“We switched to solar for environmental reasons, but the drop in our electricity bill has been the real surprise.”
- Also a family of 4, living just two streets over
- Installed a solar hot water system with electric booster
- Booster set to activate only during extended cloudy periods
- Average booster energy use: ~2–5 kWh/day
- Annual hot water cost: ~$215
- Reports no change in hot water availability compared to their old electric unit
- Electricity bills dropped significantly after the switch
Year-on-Year Comparison
| Metric | “Harris Family” (Electric) | “Martins” (Solar + Booster) |
|---|---|---|
| Daily hot water use | ~150 L | ~150 L |
| Avg energy use (kWh/day) | 12–15 | 2–5 |
| Annual running cost | ~$790 | ~$215 |
| Winter performance | Slower recovery | Booster covers gaps |
| Reported issues | Lukewarm showers, high bills | None noted |
What This Means for North Lakes Families
- A household of four using electric hot water could be spending 3–4x more per year than those using solar with booster.
- The savings aren’t theoretical — they’re happening in homes just like yours, right here in North Lakes.
- Even if you’re not ready to install solar now, knowing the long-term costs can help you plan ahead.
Average Electric Hot Water Running Costs (~$650–$925/year)
This range is pulled from:
- Australian energy data showing electric hot water accounts for ~25% of a household’s power bill
- A 4-person household using ~150 L/day typically uses 4,000–5,500 kWh/year just for hot water
- At a blended electricity rate of $0.20–$0.30/kWh, that’s $800–$1,650, but off-peak tariffs and smart timers bring that down to the $650–$925 bracket
Solar Hot Water with Electric Booster (~$65–$365/year)
This range reflects:
- Systems where solar handles 60–90% of the load
- Booster only runs during cloudy days or high demand
- Annual electric usage drops to 500–1,500 kWh/year
- Multiplied by grid rates = $100–$450/year, often less if boosted off-peak or paired with rooftop PV
This is consistent with Clean Energy Regulator estimates and feedback from solar-equipped homeowners on Whirlpool, Reddit, and product guides
Caveats
- These are average costs — actual spend varies by:
- Energy tariff (flat vs off-peak vs TOU)
- System age and condition
- Roof orientation/shade (for solar)
- Booster control (manual or automatic)
- The $790 vs $215 figures are midpoint examples, not outliers or inflated marketing
This aligns with sources like Choice, Energy.gov.au, and product-specific running cost calculators (e.g. Rheem, Dux)
RJT Plumbing’s Perspective
We work with families all over Moreton Bay and North Brisbane who want to cut costs and reduce hassle. If your hot water system is 8+ years old, it’s worth assessing whether a switch to solar could pay off.
Want to Know What You’d Save?
Book a system check-up or request a custom hot water assessment from RJT Plumbing & Gas. We’ll let you know what you’re spending now, what you could save, and whether a new system is worth the switch.
