Academics on how to save power: Turn it off when you use the most
You wake at dawn and the heat pump, fridge, and hot water are all switched off. You get home from work and, for four hours, it is the same.
But it’s not a power cut.
Instead, it would be all part of the plan under an Otago University idea to reduce New Zealand’s power use in peak hours.
With electricity use expected to increase by up to 200 per cent by 2050 – along with a drive for 100 per cent renewable energy – Otago academics Janet Stephenson, Ben Anderson and Michael Jack studied how to reduce load on the system.
Hot water cylinders, heat pumps, and fridges accounted for 50 per cent of all domestic power use but the proposal was for them to be turned off during the times New Zealand used the most power.
Essentially, the power grid was made to handle peak-power. This meant that if New Zealand used less during the peak hours, less generation and infrastructure would be needed.
The proposal was quite simply to turn those high-usage appliances off between 6am and 10am, then again from 5pm to 9pm.
“Water will stay hot in the cylinder for people’s morning showers, living spaces could be pre-warmed before 6am via smart thermostats, and fridges could remain cold despite being switched off for a short time during peak,” Anderson said.
“The combined result of these interventions across millions of households could be substantial.”
The move would reduce New Zealand’s total power demand by 20 per cent in winter, the researchers said.
According to Jack, the savings to households would be about $100 a month.
“It’s not a big deal but it makes a big difference for the overall system.”
Stephenson, Director of Otago’s Centre for Sustainability, said the projections were the first stage in determining what would be achievable in reality.
“Future work will need to consider the market systems, technologies and consumer behavioural change necessary to achieve residential demand response in practice, and how consumers would respond to the opportunity to shift their demand.”