Skip to Content
Project overview
  • Lead Organisation

    Rheem Australia


    South Australia

    ARENA Program

    Advancing Renewables Program

  • Start date

    20 December 2019

    End date

    31 December 2023

  • Project Partners
    Combined Energy Technologies, Marchment Hill Consulting, SA Power Networks, Simply Energy


The Rheem Active Hot Water Control project aims to demonstrate active control over 2,400 residential hot water systems in South Australia.


South Australia has a fast growing renewable energy industry. Currently it is grappling with excess rooftop solar PV generated during the day when there is less demand for it. This generation is often curtailed and exported to other parts of the National Electricity Market but these exports are reaching their limits. The challenge is finding ways to maximise the use of renewable energy when it is cheap and plentiful. One way this could be done is by managing when electric water heaters are charged. Currently water heaters charge overnight or, in a home with solar PV, in the early morning or evening when demand for energy is high. The Rheem Active Hot Water Control project aims to introduce new and flexible options for grid management by testing ways to manage when hot water heaters are charged.


Rheem will test the feasibility and value of aggregating approximately 2400 hot water systems to provide services in the wholesale energy and Frequency Control Ancillary Services (FCAS) markets.

As part of the trial, Rheem will reward consumers for participating in demand management of hot water systems and test incentives required for customer participation across solar and non-solar homes, as well as across different socioeconomic groups.


Shifting a hot water system’s electrical load to use solar PV in the middle of the day (at times of otherwise low demand) has potential to minimise the impacts of the solar PV duck curve. It will also help to:

  • improve renewable energy hosting capacity of networks
  • alleviate power quality issues such as voltage rise
  • increase the network hosting capacity of distributed energy resources
  • improve overall asset optimisation and use in both households and the distribution network.
Last updated 02 August 2023


Plotting next steps in distributed energy transformation

As Australians embrace rooftop solar at world-leading rates, work is underway to create a modern, fairer electricity system for the future.

What are distributed energy resources and how do they work?

According to the twentieth century model of energy distribution, large power plants fuelled by coal, hydro or gas, generated electricity that was distributed via a centralised grid.

Print Friendly, PDF & Email
Back to top