A new report commissioned by EECA highlights the importance of ripple control for hot water to reduce peak electricity demand.

Ripple Control of Hot Water in New Zealand, by Power Systems Consultants New Zealand says most electricity distribution businesses see ripple control as the best option for managing domestic hot water loads - and ripple control continues to be widely used and maintained.

EECA’s Strategy and Insights GM, Dr Marcos Pelenur says about half of residential households have ripple control and demand peaks could be lowered even further if there was higher uptake.

“At the moment the load connected to ripple control is about 15% of New Zealand’s annual peak demand and there is potential to expand that.”

However the medium-term future of ripple controlled hot water is uncertain, according to Dr Pelenur.

“There is currently no industry-wide strategy for ripple control or demand management, leading to a lack of clarity over responsibility for demand management and the pace of change.”

Dr Pelenur says in the next five years, uptake of EVs, solar power and home battery systems will increase the need to manage electricity demand.

“Reduction in ripple control of hot water is a risk in the medium term.”

The report notes that in the long-term, ripple control is likely to be displaced by a range of advanced technologies which will combine to monitor, forecast, control and coordinate energy generation, demand and storage.

View the full report: Ripple Control of Hot Water in New Zealand [PDF 2.8 MB]