Sydney Family Residence


New 4 bedroom home in Austral, NSW.
Family of 3 people, needing reliable domestic hot water supply.

System Requirements:

  • Energy efficient, reliable domestic water heating for 3 people (plus occasional visitors).
  • Maximise renewal energy generation to reduce or eliminate the home’s grid reliance for water heating.

System Solution:

  • System – 300L ENERMAX SMARTcube with Energy Smart Water ROSC20 Direct Solar PV Element.

  • Solar PV array – 7 Solar PV panels, East facing with total 2.1kW capacity.

  • Grid Electric Boost backup – 2kW AC inbuilt plug-in element.

System Performance:

  • Footprint – SMARTcube footprint is just 615mm x 595mm, smaller than conventional 315L Electric Boosted Solar tanks which range from 640 diameter.
  • Heating Performance – 92% of hot water volume since installation has been heated by solar PV input.

    Solar PV Energy Contribution – Water Heating

    Solar PV      Electric Boost

  • Energy Reduction – Since installation in July 2019, the home has self-generated 2,281kWh of electricity in 12 months – that’s energy that does not need to be purchased, a saving of $659*.
    This means that in this period the homeowner has spent just $59 on AC electric boost-backup from the grid.

    Home Energy Use – daily avg. 2019-2020

    Additionally, this saving represents a reduction in CO2 emissions of 1.8 tonnes.

  • Installation – The Energy Smart Water ROSC20 system eliminates the need for piping and pumps between tank and rooftop solar collectors (which are necessary for solar thermal water heating systems), so installation costs are reduced as are lifetime maintenance costs.

* Based on Sydney domestic electricity tariff as at July 2020 of $0.289/kWh.


This Energy Smart Water solution meets the client’s water heating requirements while minimising energy requirements from the grid, resulting in minimal energy costs. Installation and lifetime maintenance costs are reduced, compared to comparable traditional thermal solar systems.