3 Easy Ways To Heat Your Water With Solar PV
On this page, you’ll discover three simple yet highly effective methods to heat your water using your solar PV system.
Water Heating Options For Homes With Solar
1️⃣ Immersion Diverter Channels Excess Solar Energy
Heat Water With Solar – Solar diverters are devices designed to maximise the use of the free electricity generated by your solar PV system by automatically directing surplus energy to heat your hot water once your essential household appliances have finished running. This means that instead of exporting unused solar energy back to the grid, it is stored in the form of hot water for later use, increasing your self-consumption and reducing reliance on your boiler or immersion heater. These systems were particularly valuable before the introduction of the Microgen scheme.
This scheme pays homeowners for exporting excess electricity, and before the availability of smart meters with low night-rate tariffs that allow for cheaper electricity consumption during off-peak hours. While still beneficial for increasing energy independence, their role in household energy management has evolved alongside these newer technologies and tariff options.
2️⃣ Schedule Immersion Turn On At Peak Solar Generation
During peak solar generation times (e.g. 12pm to 2pm) you can schedule your immersion to turn on and your panels will generate enough power at this time to heat your water.
3️⃣ Utilise Use Low Night Rate Electricity To Heat Water
Thanks to smart meters you can utilise lower night rate electricity to heat your water. Most electricity suppliers offer a much rate at approximately 2am to 5am. Use this rate to time your immersion or charge a solar battery.
Immersion Diverter
An immersion diverter, also known as an immersion optimiser, is a water heating module that when added to your solar PV system, uses excess energy generated to heat your water cylinder rather than sending it back to the grid. In the past this was very handy, and a very smart use of the energy you generate. But now with smart tariffs and the Microgeneration Scheme it is no longer needed in most homes.
Eddi & iBoost Immersion Diverters
Why Immersion Diverters Are No Longer Necessary
Before smart meters were introduced in 2021, homeowners gave away the excess electricity generated by their solar PV panels to the grid for free. So an immersion diverter was a smart investment. Instead of giving electricity away, you could turn the excess energy generated by your solar panels into hot water.
However, nowadays with the Microgeneration Scheme you get paid by your energy supplier for any excess electricity you send back to the grid. And with an optional battery storage add-on, you will significantly improve your consumption of the solar energy that is generated.
Turn On Your Immersion During Peak Solar Times
The most common way homeowners use their solar PV panels is to run appliances while during peak daylight times. If you are not home during the day that energy generated will go back to the grid and your electricity supplier will credit your account under the Microgeneration scheme. But it is more economically beneficial to use the energy you generate. A smart way of doing this is to schedule your immersion to turn on during peak solar performance. Also homeowners who are not home during the day could benefit from solar battery storage.
Use Cheaper Night Rate Electricity
Many smart meter plans allow you to buy back electricity at a much lower rate in the middle of the night. If your primary goal with solar is to generate hot water, it’s generally more cost-effective to sell the electricity you produce and set a timer to turn the immersion on during off-peak tariffs to take advantage of night rate energy (three hours for the price of one!). This also works for solar battery storage. Fill up your battery with cheap electricity for use in the morning. Then use your panels to charge your battery for use in the evening.
Conclusion
In summary, our experience shows that the most efficient and cost-effective way to heat your water—particularly if your immersion heater is your primary source of hot water—is to install a reliable time switch.
This allows you to take advantage of low-cost night-rate electricity or stored battery energy, ensuring that your hot water is ready exactly when you need it.
By automating this process, you can reduce energy waste, lower your bills, and make better use of the renewable energy your system generates. Whether you are looking to optimise your current setup or design a completely bespoke solar PV system, our team at Energlaze can guide you through the best options for your home.
For expert advice, a tailored solution, and a free, no-obligation consultation and quote, contact Energlaze today.
