Geothermal has been part of Contact Energy’s DNA since it was established back in the late 1990s – but its roots go much deeper than that.
Initially a State Owned Enterprise (SOE), Contact Energy was born from the original Electricity Corporation of New Zealand (ECNZ) and in 1998 was the first of the electricity SOE’s to be privatised.
When established as an SOE it was blessed with a number of assets including the original Wairakei Geothermal Power Plant on the Wairakei geothermal system.
The first of its kind anywhere in the world, Wairakei Geothermal Power Plant was built in 1958 and has just let off steam celebrating its 60th birthday.
So, for many staff who switched across from the old ECNZ to Contact Energy, there is a strong feeling that geothermal DNA stems right back to the early pioneering days of Wairakei.
Mike Dunstall, Contact Energy’s General Manager of Geothermal Resources says that much of Wairakei’s technology didn’t exist before Wairakei and had to be pioneered through good old-fashioned Kiwi ingenuity.
“New Zealand has a reputation for pushing the frontiers of this kind of stuff. That technology has now been copied and used around the world in other geothermal plants.”
Mike reckons that while necessity may have been the mother of invention once upon a time – Kiwi’s are still doing it – even though necessity may no longer exist.
“That culture of invention feeds on itself and if the next generation sees it going on around them they come to expect to do it themselves.”
There are now five geothermal stations in Contact’s fleet within the Central North Island – Te Mihi, Wairakei, Poihipi Road—all on the Wairakei geothermal system, Ohaahi on the Ohaaki field and Te Huka, which is on the Tauhara geothermal system.
The Wairakei Geothermal Power Plant was the first of its kind when built in 1958.
Mike explains that Contact Energy has geothermal capacity for about 430 megawatts. “Last financial year we produced 3323 gigawatt hours of power which is probably enough for 500,000 typical kiwi homes.”
Most of the heat energy produced from the geothermal wells gets turned into electricity in Contact’s power stations, then channelled into the national grid where it can be distributed better to customers right around the country.
“We can run geothermal 24/7 365 days a year. Geothermal energy is what’s called baseload in the total energy mix – so we run all the time,” says Mike.
“The hydro energy is quite good at going on and off to meet the peak times of the day when people have more demand. So geothermal sits at the bottom and keeps running your TV when its on standby and your deep freeze while you’re asleep in bed – then hydro will come on when you want to cook your dinner.”
Mike says that some steam from the geothermal system is supplied directly to industrial customers.
Tenon Ltd, a wood processing mill in Taupo switched from natural gas in their timber drying kilns to geothermal in 2006 and is currently Contact’s biggest user of direct use geothermal energy.
“There’s tremendous potential for industry to use geothermal as direct heat, particularly in wood and forestry products but industry really needs to be close to the energy source in central North Island as it doesn’t transport well over long distances.”
Mike explains that geothermal is also quite unique in that it creates the opportunity for other side-stream industries to co-exist working along side the power plants.
“That’s one aspect that’s been under-emphasised in my view and we’re working hard on promoting more of that. At Wairakei there’s an
aquaculture operation growing Malaysian fresh water prawns. The prawns would freeze to death in New Zealand but the water in the Waikato River is warmed using our geothermal fluid and the prawns live there quite happily.”
Reflecting on the future of geothermal as an energy source in New Zealand, Mike has no doubt that it will continue to grow.
“I think that geothermal is one of the cheapest renewable energy options developable in New Zealand. There’s still a lot of geothermal that can be developed—even on the existing fields.”
He says there are some geothermal areas that you will never want to develop—places where there are beautiful surface features that have enormous scientifi c and tourism benefits. “But there’s a tremendous amount of potential without going near those areas.”
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