A quarter of New Zealand's peak electricity use could be shifted to times of lower demand, lowering household bills and saving up to $3 billion in infrastructure investment, a new report says.
The Energy Efficiency and Conservation Authority (EECA) commissioned the analysis and said lower network costs from shifting demand should flow through to households and businesses.
Households had the most potential to shift their demand, but some industrial processes and manufacturing could also make changes with the right financial incentives, the report found.
New Zealand's electricity demands will grow by 35% to 82% by 2050, the Ministry of Business, Innovation and Employment estimated last year.
Upgrades to accommodate growing demand could cost tens of billions of dollars, EECA chief executive Marco Pelenur said.
The electricity network is built to handle peak demand, which only occurs a few times a day for short intervals. Spreading the power load could help to defer or avoid increasing demand capacity.
"This [analysis] shows we could save billions as a country just by moving when we use power."
Rooftop solar and batteries could help shift household demand, but much lower-cost measures - that would also save households money - were also available.
That included Wi-Fi-enabled devices that could be retrofitted to most hot water cylinders and heat pumps for a few hundred dollars.
The devices, which are being trialled by EECA in hundreds of households at the moment, allow users to control appliances remotely, such as switching on a heat pump in the late afternoon before peak demand kicks in, so a house could already be warm when people arrive home.
"The early results from the pilots show households are saving on their bills right now - and that doesn't include the system benefits of deferring network upgrades," Pelenur said.
Peak demand savings would be even bigger if flexible energy use were enabled at scale, and people were paid directly for shifting electricity use off-peak, EECA said.
University of Auckland professor Nirmal Nair said demand-side flexibility, as proposed in the report, had been "widely touted", but if households and other retail customers were being encouraged to change their usage, then what they were charged should be revisited.
"Expecting [retail customers] to invest in more technologies to give value to other upstream agents like electricity retailers and distribution companies appears unreasonable, if not unfair."
Major electricity users surveyed as part of the report said continued production was their top priority, but many were open to more flexible electricity use if it did not disrupt production, or cost more money than it saved.
The report identified food processing in Bay of Plenty, Waikato and North Canterbury, farming in Canterbury and Waikato, and offices in the main centres as having significant potential.
That could be achieved with similar technology to households, such as battery installation and 'smart load controllers' to defer electricity usage to lower-demand periods, when it was possible to do so.
The report suggested a "robust reward system" to compensate industries for their participation. That could include direct payments, along with long-term energy cost reductions, it said.
