Andrew and Lynn Johnson have just joined up to the world's fastest-growing source of new energy: the sun.
The couple at Farm Cove, Pakuranga, are in the midst of a major renovation to their house and have recently installed solar panels in what HRV's solar engineers say appeals as a textbook case of getting the most out of solar power.
"I was sick of our winter power bills," says Johnson. "They weren't just high, they were excessively high. I don't know if it was our old hot water cylinder or some kind of power leak somewhere but I'd had enough."
Another major factor was Johnson, 44, has a medical condition that led him to retire early from his profession as a lawyer. That, however, meant he was home during the day – a key element in homeowners getting the most out of their solar power system.
HRV Solar Programme Manager, Leon Hayward, says best performance and savings are made if the solar power generated is used during the day. So, even if the householders are all out at work during the day, Hayward encourages them to change their habits and use timers to ensure washing machines, dryers, dishwashers and hot water cylinders are all active during the day.
It's too early to measure the Johnsons' savings but Andrew says: "We were hooked up only about a week ago but I know already we have done the right thing."
As part of the renovation, they are fully insulating the house and installing a ducted air conditioning system throughout. Johnson, because he is already at home during the day while Lynn heads off to work for a fruit export company, does the housework, washing, drying and other power-hungry functions.
They will monitor their power generation and usage for a year before deciding whether to buy a storage battery – enabling solar power households to store excess energy and use it during the evening when solar power is not being generated.
"I am also a bit of a taxi driver for our kids [aged 10 and 8]," says Johnson, "and I am thinking I may look at a small electric car. I could then use the solar power from the battery to charge it."
Another reason for going solar was environmental consciousness: "Renewable energy is an easy way to help reduce our dependence on water-based and coal-based power."
The only gripe Johnson has is that the current price to householders for supplying extra electricity back to the grid is too meagre. He says grid power costs about 27c per kilowatt hour while the buyback rate is only 8c per kilowatt hour.
However, as at December 1, more than 15,000 New Zealand homes were generating solar electricity, with almost 3300 homeowners installing solar panels in 2017 – up more than 10 per cent over the same period in 2016, according to Electricity Authority chief executive Carl Hansen.
Even more, research shows most Kiwis see sustainability as a highly desirable part of life, according to HRV CEO Bruce Gordon: "Almost three-quarters of Kiwis want to live in an energy-efficient home with sustainable elements such as solar power and recyclable water.
On the global front, the International Energy Agency said late last year solar power was the fastest-growing source of new energy worldwide in 2016, with new solar capacity overtaking the net growth in coal – previously the biggest new source of power generation.
Dr Fatih Birol, executive director of the IEA (funded by 28 member governments) said: "What we are witnessing is the birth of a new era in solar photovoltaics (PV). We expect solar PV capacity growth will be higher than any other renewable technology up to 2022."
With solar systems' price falling and the cost of mainstream electricity continuing to rise, more Kiwis are deciding the time is right, says HRV's Hayward, who has worked on some large solar power projects in California.
"It is all about self-utilisation," he says. "Those people who use a hot water diverter and timers for their heat pumps, washing machines, dryers and the like so they operate during the day are the ones who notice the biggest savings."
People who stay at home or work from home are likely to use more power during the day, when solar power is generated. People not at home during the day have to change their lifestyle to one involving timers and daytime tasks – as he says a household using 70 per cent of solar power will make bigger savings than one which uses only 30 per cent.
"It's all about training yourself and changing your habits – then you really notice the difference."