Genesis hot water trial cuts energy use & eases grid strain

Genesis is reporting a reduction in energy usage for customers involved in a trial that remotely controls hot water heating during peak demand periods.

The programme, involving approximately 17,000 Genesis customers, uses remote technology to shift hot water heating to times outside of electricity peak periods. According to Genesis, this approach reduces household energy use from hot water by about 10 per cent while allowing customers to maintain their usual routines.

The system's operation smooths out hot water demand on the national grid, helping to relieve strain at peak times, particularly during the winter months when overall electricity usage is higher. Energy savings achieved through the programme are also expected to translate into lower bills for participating households.

Energy demand and national grid

Genesis is also partnering with GridSmart, a division of Rinnai, to test a new device that uses artificial intelligence to optimise when hot water cylinders are heated. This technology aims to refine demand management by customising schedules to the patterns of individual households.

Stephen England-Hall, Chief Revenue Officer at Genesis, highlighted the significance of water heating on typical residential consumption. "Water heating is one of the biggest contributors to household electricity use accounting for around 30 percent of the energy used by an average household," says England-Hall.

He added that as New Zealand shifts towards greater electrification, innovation in managing energy demand is increasingly important: "As New Zealand moves towards wider electrification, it's vital to ensure growing demand doesn't place unnecessary strain on the grid."

England-Hall explained the goals of the initiative: "We're looking at how smart, automated technology can help reduce peak demand, lower customer bills, and maximise use of renewable generation – all while keeping the experience seamless for customers."

Programme performance

Genesis reported that since the start of the programme, around 500 MWh of energy demand has been shifted away from peak hours. Analysis indicates that, for participating customers, an average of 32% of their hot water load has moved out of the morning peak and 14% out of the evening peak.

In total, over the past 10 months, Genesis has shifted approximately 1.43 GWh of hot water load to non-peak times. The company states that this is equivalent to the electricity consumption of 200 homes over the course of a year.

England-Hall noted that the programme is still being refined. "We're still learning and optimising the programme so expect benefits to customers and the grid to increase," he said.

New technology trial

The next phase involves a trial of a GridSmart device, which is designed to be installed on existing hot water cylinders. The technology provides real-time insight into a household's water usage, improving the accuracy with which electricity demand can be balanced against actual need.

Charles Chu, General Manager at GridSmart, described the advantages of the technology: "The system combines Rinnai's expertise in hot water with AI to assess how much hot water is needed and when - putting the customer's needs first, while utilising renewable generation and reducing grid congestion."

"Current solutions are blunt and not dynamic - this device means homes can have family over unexpectedly, or enjoy a long shower after a hard day without having to worry about their water running cold."

Chu highlighted the expected efficiency gains: "We're aiming to save 40-60% in addition to what Genesis have been able to achieve with its current demand management programme."

The GridSmart device leverages Rinnai's expertise in hot water and appliance design, and is being trialled by Genesis staff ahead of a possible wider rollout. England-Hall commented on the collaboration: "We're excited by the trial. Genesis is always looking for innovative technological solutions to help our customers save money and reduce overall energy demand, which is also great for New Zealand," he said.

Energy flexibility strategy

This initiative forms part of Genesis' broader energy flexibility programme, which is designed to build more resilience into the national electricity network by using technology to create outcomes beneficial to consumers, retailers, generators and distribution companies.