Trial sees power companies save cash

A trial project between eight South Island electricity lines companies to reduce peak demand on their networks is paying off by deferring the need for expensive transmission upgrades, says Network Tasman chief executive Wayne Mackey.

The two-year load controller project, which began at the start of winter, is estimated to have reduced load at peak times by 30 megawatts during winter, the equivalent of removing 10,000 homes from the national grid.

It works through the Orion network control room in Christchurch. During periods of high demand, "ripple" signals are used to co-operatively control household hot water cylinders throughout the trial area.

Mr Mackey said it did not mean that householders would end up with cold showers. It worked to ensure there was an adequate and consistent supply of hot water to customers.

The use of ripple control was not new, but the project's difference was in the networks working together to reduce total peak demand, such as when it was a cold day in Christchurch but warm in Nelson, he said.

It would benefit customers by reducing transmission upgrades, which cost millions of dollars, and potentially lowering the wholesale power price, he said.

"The growth in the upper South Island is 20MW to 30MW a year. What we are doing will take a couple of years' worth of that."

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