Certified Electrical Compliance For Australia, NZ, Europe And UK

SOLARIMMERSION optimises the efficiency of photo-voltaic and other microgeneration systems by preferentially diverting the free surplus power to your hot water cylinder or other resistive devices Eg., Spa Pool Heating, Under Floor Heater, Swimming Pool Heating, Battery Storage.

Efficiency & Performance – Use Almost 100% of Free generated power

With solar PV, almost 50% of the energy is exported to grid. Utilise close to 100% of your FREE generated power by installing a highly efficient SolarImmersion unit.

Manual Override / Boost Function

Inbuilt override/boost facility to turn on the Water heating on manually if required.

Multiple Loads

SolarImmersion can drive multiple loads, so when the water is hot enough and the thermostat cuts off, a second load could be activated. Designed and Made in the UK. SolarImmersion is the leading PV water heating/solar hot water switch/controller manufactured in the UK.


Your hot water typically accounts for around a third of your energy bills. Most hot water usage occurs when you are generating very little or no solar power, i.e. first thing in the morning and in the evening. Under normal circumstance you hot water cylinder will start reheating immediately from grid power as soon as the temperature drops and you will be getting almost zero benefit from your solar installation.

The SolarImmersion unit electronically disconnects your hot water cylinder from the grid and monitors import/ export power via a sensor clamp (current transformer) connected to your grid power infeed. Self generated power will first go to fulfil household needs. As soon as the unit detects that there is surplus power (as little as 20W) it will divert this to your hot water cylinder and will continue to divert surplus power to your hot water throughout the day. With a single load system the surplus will flow back to the grid once the water is hot and the thermostat cuts off.

To further improve the efficiency of the system you can connect a secondary load (load 2) to the SolarImmersion unit. Once the hot water cylinder has reached temperature the unit will stop diverting for 3 minutes and then it will start diverting any surplus to load 2 for a nominated time (either 30 or 60 minutes) before switching back to load 1 to see if it requires topping up. If load 1 does not require any topping up, after 3 minutes the surplus will switch back to load 2 for the nominated period.

If neither load 1 or load 2 require any power, the surplus will be exported back to the grid.

Why you need SolarImmersion?

  • Uses almost 100% of your free generated power
  • Reduces your energy costs and bills
  • Works with Solar Panels, Wind & Hydro
  • Doesn’t affect the Solar PV system warranty
  • No plumbing alterations required
  • Maintenance free with no moving parts
  • 1 year return to base warranty
  • Easy installation by registered electrician
  • Silent operation
  • Works with grid tied solar installations

Purchasing SolarImmersion

NOTE : The unit needs to be installed by a qualified and authorised electrical professional.

Solar choice - Australia article

Australian solar brokerage & comparison service Solar Choice posted an informative piece about the financial case for choosing SolarImmersion over batteries. "Batteries remain expensive and - for now - only make financial sense in a limited set of circumstances," reads the article. "For most solar homes, a more cost-effective approach would be finding ways to put their solar to use without batteries - and storing it in the form of hot water is a fantastic way to do so."


SolarImmersion Presentations

SolarImmersion - How it works
SolarImmersion - History and case study

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