When you see your hot water bill, you might close your eyes and wish it was possible to just be rid of it. While it might sound like a fantasy, for some, it can be achievable.
Before you read any further, we need to be honest with you: eliminating your running costs won’t come for free. You’ll have to spend a chunk of money upfront – and have a good solar system. What you get from that, though, is two decades of (virtually) free hot water – you’ll earn back the upfront cost over time. If you’re still interested, then read on.
Using the right technology
Electric systems, whether storage or instantaneous, just aren’t going to cut it for anything but the smallest households with minimum hot water usage. They turn 1kW of electricity into 1kW of heating power, and for large families, that’s going to draw a lot of energy from the grid (or suck up the power your solar panels generate). It costs a family of four around $920 annually to run an electric storage system.
Gas is cheaper. But cheap is not free, and you’ll still have to pay for supply and use.
A solar hot water system can have remarkably low costs, but does have a few drawbacks. For starters, you take up roof space that could be better used for solar panels. Inevitably, you’ll end up needing hot water on days when it’s too cloudy or dark for solar hot water to meet the demand. That means the system needs a gas or electric booster, which you’ll have to pay for.
While it might not always be the right option for you, if your goal is to wipe as much of your ongoing costs as possible, then you can’t look past a good heat pump. By taking heat from the air and using it to heat water, heat pumps can operate far more efficiently than other methods. The best will turn 1kW of electricity into 5kW of heating power, which is an 80% reduction in cost compared to an electric storage system.
There aren’t a lot of drawbacks to a good heat pump. With that, you might wonder, “why aren’t we all using heat pumps then?” The answer lies in the one big drawback that heat pumps do have: upfront cost.
A great heat pump will cost somewhere in the ballpark of $5,000. You’re paying for top-level technology, and it’s that technology that can help bring your bills towards zero.
How a great heat pump reduces hot water bills
There are three ways a hot water heat pump system slashes bills. They are:
- Efficiency: As mentioned above, being able to turn 1kW of power into 5kW of heating is a huge leap above conventional electric systems.
- Intelligence: The best heat pumps integrate seamlessly with solar. By running at peak generation times, when your solar system is providing the most, you store energy as hot water for when you need it.
- Reliability: Unlike solar hot water, night and shade aren’t a problem for heat pumps. For the best models, as long as the temperature is above -10°C, the unit will continue to work.
There are sites that promise free heat pumps through government rebates. They will absolutely make a difference to your bills, but won’t bring them down as much in the long term – and they definitely won’t last as long. To explain why, let’s talk about how a cheap or free heat pump performs in the above three categories – compared to a premium model.
Efficiency: While premium models, such as those offered by Reclaim Energy or Sanden, average 500% efficiency (5kW of heating from 1kW of power). Lower end heat pumps will average 200% to 350%, which is good, but a much lower decrease over time.
Intelligence: Having a smart controller is, as you’d expect, more expensive than not having it. Paying less upfront means you lose out on solar integration, which will lead to more times when the pump has to pull from the grid. That, in turn, increases the running cost. Additionally, with less efficiency, it takes longer to heat the tank. These cheaper systems have trouble heating an entire tank within the peak generation period.
Reliability: Lower end systems require an electric booster, as they cannot operate when it gets too cold. That causes extra power draw from the grid, and means you’re no longer using the efficient heat pump – instead, you’re relying on an electric element which is much more expensive to run.
Getting to zero
It’s unlikely that you’ll see a perfect zero on your hot water bill, but that’s not quite the same as having free hot water. If you have the right sized solar system, you’ll pay barely anything to heat your water – you’ll pull from the grid minimally. Eventually, you’ll be paying more for the water than for the electricity.
But the hidden benefit is that efficiency. If you have an electric storage system and get an efficient heat pump, one which reduces your power use by 80%, it frees up your generation. 80% of what you would’ve used to heat your water can now be used to power the rest of your home, or be fed back into the grid. The savings you make everywhere else means that, while your hot water isn’t technically free, it is practically free. For all intents and purposes, you’re spending nothing (once you account for offsetting your power needs elsewhere).
Conclusion
Can you run a hot water system for free? Basically, but not if you get the system for free. It requires a significant investment, though it’s one that pays for itself over time.
We’ve got a wealth of knowledge on this blog about heat pump hot water. Once you’ve read enough and know you’re interested in upgrading, get in touch with our team and we’ll take it from there.
