Grid the key to green power, says energy boss

Keith Turner

Meridian Energy chief executive Keith Turner, whose company runs New Zealand's biggest windfarm, supports the plan. He argues that if people want clean, green sources of electricity, they have to be prepared to upgrade the grid to carry that power to homes and businesses.

New Zealand's electricity grid is so overworked that some lines cannot be taken out of action for servicing, says an industry expert.

"That is unheard of in the Western developed world," says Meridian Energy chief executive Keith Turner, a 30-year veteran of the energy sector and one of its experts on transmission and the national grid.

While other generators continue to burn fossil fuels in power stations and draw up plans for new coal-fired stations, Dr Turner has said Meridian will pursue only renewable electricity generation options - hydro and wind in particular.

The company runs power stations on the Waitaki River and the country's biggest windfarm near Palmerston North. It also owns the Manapouri hydro station, New Zealand's biggest at 585 megawatts.

Dr Turner earned his PhD in "high-voltage direct current integrated with AC transmission", so the national transmission grid is a subject close to his heart.

And the planned new line through the Waikato has his support.

"New Zealand needs a very strong transmission grid. We are a long, stringy country ... and the nature of our electricity supply - two-thirds comes from hydro, some from geothermal and some from fossil fuel thermal - means our grid is called upon to perform functions that you don't normally find in other thermal-based systems."

Dr Turner says the grid needs to transfer power in two directions, coping with a wide range of conditions affecting the wind generators and hydro stations, and also meet the growing northern population.

Everyone in Auckland wants continuous electricity - the city experienced the alternative in the 1998 cable failures - but this depends on transmission.

"There is a wide call from people affected by transmission lines to say: put the generation next to the load. It sounds like an incredibly logical thing to do, but developing Huntly is putting generation close to the load. Yet you still can't supply Auckland if you don't strengthen the transmission through Huntly."

Dr Turner agrees with Transpower's argument that building power stations next to the big cities does not avoid the need for new transmission lines.

The trick is to build both, so no one becomes too reliant on any one part of it. Power stations close to town operate alongside electricity brought up from remote windfarms and hydro stations.

"You still need to develop transmission to operate in an integrated system ... you can't escape transmission."

New Zealand is lucky to have access to cheap electricity generated from hydro dams - which cannot be shifted close to Auckland.

"You can't shift the wind, you can't shift the hydro, which is the cheapest form of energy.

"You can with coal [but] does Auckland want to be rained on by sulphur dioxide? I doubt if it will.

"You can shift gas, but only to a certain extent. I suspect Auckland would not like a dirty big LNG [liquefied natural gas] terminal in the middle of the city.

"While it sounds nice, the argument for shifting generation closer to the load is made by those affected by transmission - electricity is one of those things, unfortunately, where everybody wants it but nobody wants the implications of its supply."

Dr Turner's enthusiasm for renewable energy means that a good transmission grid is needed.

He says it is time to think about what the national grid really is - not a profit-making enterprise for a company, but infrastructure.

He compares it to roads, built by the taxpayer for the common good of all New Zealanders. "The grid is like the road. The grid has to be a good strong inter-connected system to get the very best out of New Zealand indigenous energy resources."