Solar PV Knowledge Bank

iBoost: Solar PV Optimiser for Hot Water

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Why export when you can divert excess electricity and make the most out of your solar energy?

Solar panels generate the most energy during the day, while most households tend to use most of their electricity in the evening. If there is insufficient load in the house, excess generation from the array will be exported to the grid. This is where an add on like a solar PV or immersion optimiser, such as the iBoost, comes in.

The iBoost monitors electricity export using a sensor attached between your main meter and consumer unit. If the sensor detects that the property is exporting electricity, the device diverts the excess power to the immersion heater in the hot water tank. This reduces the fuel required by the boiler, thereby cutting fuel costs.

If an electrical appliance is switched on in the property, the device will reduce the power diverted to the immersion. Electricity usage throughout the home is always given priority use of the energy generated by the PV array.

The device ensures you make the most of the energy generated by the PV array, even when you are out of the house. As long as your hot water tank has sufficient ‘capacity’ (which can be achieved by setting the normal hot water heating to come on after the sun has gone down) you should be able to use 100% of the electricity generated by your PV system.

Typical savings

  • A 3.92kWp PV system will generate around 3364kWh per year.
  • On average, half of this electricity is exported back to the grid: 1682kWh.
  • By diverting this to the immersion heater in the hot water tank, the homeowner saves 1682kWh of heating fuel.
  • Suppose your boiler is 80% efficient and works off gas at 4.8p per kWh. This gives an effective fuel cost of 6p per kWh.
  • The total saving is therefore 1682kWh x 6p = £100.92 per year.
  • This increases to over £120 if you use oil or LPG to heat your water.
  • Payback on this size of system is typically 5 to 7 years.

The Solar iBoostiboost.jpg

We recommend the Solar iBoost to provide hot water via excess PV electricity. It is wireless so there are no cables to run.



iBoost features and benefits

  • Works with existing immersion elements. You can keep your existing immersion, with no need for expensive replacement work.
  • Added functions allow for a timed or manual override that will turn the immersion on regardless of whether there is excess generation from the PV array.
  • LED screen displays which show the status of the device and whether your tank has reached optimum temperature.
  • The unit measures and records the amount of energy applied to the immersion. Real time output and historical data available.
  • 2 year product warranty.

Get in touch today for a free iBoost or PV quote: Request a quote