In 2023, approximately 4,000 gigawatt-hours of renewable energy—around 9.3% of utility scale renewable generation — was wasted, or “curtailed”. Much of this energy could be directed to off-peak hot water systems if those systems’ timing could be changed from overnight to daytime peaks. Such a change could provide flexible demand for renewable energy, delivering financial savings, lower emissions, and lower gas demand. 

Key Findings

• Annual forced curtailment for 2023-24 was around 4,000 gigawatt-hours (GWh).
• This represents around 9.3% of Australia’s total generation from wind and utility solar.
• Historically, Off-peak hot water systems have been set to operate at night, but they could be reconfigured to consume electricity during the middle of the day, when there is an abundant supply of renewable electricity.
• Switching off-peak hot water to the middle of the day could provide around 4,000 GWh of flexible demand, almost the exact current level of renewable curtailment.
• This could save up to $6 billion in household electricity and energy costs by 2040.