Another reason was a more obvious one - the rising cost of supplied power from the national grid.
"Investing in your own system means you are locking in your future energy prices," Mr Duncan said, agreeing that no, the sun does not put its prices up.
There was also the potential, depending on what form of system and size was installed, of actually selling excess power back to the grid.
The costs of securing your own power system?
While the average cost of a set-up for what could best be described as an average house swung around the $10,000 mark there were systems of lower energy output, but still capable of carving big holes in electricity bills, which could be installed for around $6000.
"It all depends on the energy consumption - the size of the house - what's needed," Mr Duncan said.
That sort of outlay generally took about seven to 10 years to pay off. The top-end systems, capable of producing about 7000 kW of energy a year, came with a price tag around $16,000.
Some people simply wanted solar water-heating while a growing number wanted solar-produced electricity - for lights and appliances.
The advances in technology meant systems were now well in place where solar-produced energy could be stored and Mr Duncan has recently returned from a conference in Tauranga centred around the increasing development of solar batteries which were now becoming available.
"People can become less and less reliant on the grid."
That meant that power made could be stored with the excess available for use where power on the property was needed.
Which meant the darkness of nights or cloudy days had no adverse effect.
"A lot of the market is people looking forward to retirement and reducing their costs," Mr Duncan said.
Many had accumulated savings and effectively saw it as an investment.
In retirement years, when incomes reduced, being able to more than halve the power account was invaluable.
"And with solar you can do that."
Mr Duncan said there had also been a surge in commercial systems.
He had installed systems at schools, daycare centres and businesses.
He said for the commercial sector solar was ideal as they generally only opened, and used power, during daylight hours.
"They are on the increase too."
Kevin Hunter, the director of Hastings-based Cellpower has been involved in solar electricity installation for 15 years and said the move to using the power of the sun was "very much" on the increase and he predicted the rise would continue to increase.
Apart from simply wanting to draw less power from the grid people were moving toward solar as it had become "very" cost effective to do it now.
As well, technology had surged ahead and the componentry around panels was getting better and better.
Hunter's company is focused on solar electricity systems rather than solar water heating systems, and he said that as well as a growing number of residential homes, Cellpower also provided power to sites wherever it was required - even mobile motorhomes.
Systems could involve eight panels up to 20 panels depending on the size of the home and the power requirements.
His costings echoed others - from $6000 to $12,000 and depending on how much power was used the quicker the payback became - around seven years.
"Yes it is very definitely on the rise here and we are following a worldwide trend."
The International Energy Agency expects that by 2030, 11 per cent of the world's power will be generated by solar PV systems.
