Doug Heffernan can remember the exact date of his first day on the job.
It was December 15, 1998, and the 45-year-old had just been given the reins of, well, not much actually.
A clean sheet of paper, he calls it; Heffernan had been charged with constructing a new company from the carcass of the Electricity Corporation, and ahead of him lay an unknown landscape - New Zealand's newly privatised electricity industry. Sixteen years later and the landscape has shifted again, but this time Heffernan is bowing out. His time at the helm of Mighty River Power will conclude 16 years, eight months and 16 days after he took the job on.
Under his steady Southland hand (Heffernan is an "economic refugee" from just outside Gore), Mighty River Power has gone from providing 10 per cent of New Zealand's energy to 17 per cent. It is now ranked among the top 15 companies worldwide in geothermal power generation, racking up 15 stations in the 2000s.
Most recently, it stumbled its way onto the New Zealand stock exchange as part of the government's partial sale of state-owned assets - although the shares remain below the issue price. Heffernan says the court battles and political posturing that surrounded the listing were the low point of the last three or four years.
"If I was a benign dictator, would I have done it exactly as [the government did]? . . . Probably not. I would have done it slightly differently, but it doesn't really matter, because I'm just an employee," he says.
"I think we've done a bloody good job of that, despite all the noise and distractions going on outside."
Ironically, as troubled as the listing was, it was part of what has kept him in the job for more than a decade. Change has kept things interesting, he says.
"If the job was the same as it was when I joined in December 1998, then I wouldn't have stayed."
"The first phase [of business] was actually putting together the Waikato hydro with the Mercury Energy retail business and putting together a management team." The new company had a lot of debt, but "once we had that under control, the focus was on growth, for most of the rest of the 2000s it was the geothermal growth story".
The geothermal projects, which have seen the company partner with local iwi, are among his proudest achievements. The partnerships see a joint venture set up between iwi and company, with subsequent responsibility for managing the resource shared, along with any revenue generated. Not only has it launched "security of supply" to a standard Heffernan says exceeds anything he has seen in 40 years in the industry, it's also benefiting local communities.
"There's thousands of people in those tribes and trusts who are benefiting from the way in which New Zealand is using those great taonga," he says.
"I feel really good about that."
The geothermal phase has also been a journey into renewable energy for the company, and it happened without the help of subsidies relied on so heavily elsewhere in the world.
"As Kiwis we probably don't celebrate the fact that our electricity supply is very highly renewable, 75 per cent, and actually has been growing quickly, most countries in the world are nowhere near that."
In stark contrast to the highs was the death of school-teacher Folole Muliaga in 2007. Muliaga died after Mighty River Power's retail arm Mercury Energy cut the power supply to her home because of overdue bills. She had been on an oxygen machine.
"I made a commitment to Mr Muliaga. I said, ‘we're going to put this right, we're going to do everything possible to make this right'," says Heffernan. "This was me at the time, ‘We gotta find a better way to deal with that', and we have come up with a better way."
When it comes to what to watch out for in the future, Heffernan believes it is the electrification of transport.
"Ngatamariki, that produces enough energy in a year to fuel 350,000 motor vehicles and their transport needs. The cost of filling up a tank is less than 20 per cent of your pump cost."
"Electricity in New Zealand, compared to petrol, is really, really cheap and we have got a lot of it that's renewable."
Heffernan has seen a lot of change in 40 years, "but I think in the next 40 years we'll see even more".
- The Press