Powerful plans to boost energy flow

By CHRIS DANIELS

Low hydro lakes and warnings of power shortages have brought New Zealand's need for more power stations sharply into focus.

But despite record prices for wholesale electricity and demand expected to rise by 2 per cent a year, electricity companies are not rushing to build big stations, preferring to concentrate on replacing older, more inefficient stations.

There is enough generation capacity around, Mighty River Power chief executive Doug Heffernan says.

He says this was demonstrated by the big thermal stations not even running at full throttle until late last month. If these stations had been run harder there would have been more water left in the lakes.

The big four power generators have the capacity now to produce 6971 megawatts of power. Here are their plans.

Genesis

Environment Waikato has just given approval for the SOE to start a $400 million extension to its Huntly power station. The new station will generate 400 megawatts of electricity, alongside the existing gas and coal plant producing 1400 megawatts.

Due for completion in 2005, Genesis says the plant will be 50 per cent more efficient and less polluting. Wind power and "mini-hydro"schemes are also planned.

Meridian

The SOE has spent $200 million building a new "tailrace" tunnel at its Manapouri hydro station.

New Zealand's largest generator, Meridian has the capacity to produce 2323 megawatts of power.

When commissioned in April next year, the tunnel will help generate a further 170 megawatts of electricity - enough to power 64,000 homes, or a city the size of Dunedin.

Meridian likens the project to "putting a turbocharger" on the power station, as the extra power will be generated from the same amount of water.

Further down the track, but much more exciting to Meridian, is Project Aqua, its dramatic plan for the Waitaki River.

Water not now used by the eight power stations on the Waitaki River would race along canals, feeding into a sequence of six small power stations, each with a single turbine.

These stations would supply as much power as the Clyde Dam - around 8 per cent of New Zealand's entire energy needs.

At 570 megawatts, this is the biggest single-generation project planned for the next few years.

Meridian is touting Project Aqua as clean hydro production without the environmental destruction caused by the building of huge dams.

Contact

The only one of the big four generators that is not an SOE, Contact Energy wants to build a gas-fired power station known as Otahuhu C beside its existing plant. This would generate a further 400 megawatts, or 9 per cent of electricity demand.

Contact is also planning to build another small gas-fired power station at Whirinaki, Hawkes Bay, designed to provide between 80 and 100 megawatts.

Mighty River Power

The smallest of the big four generators, with 1148 megawatts of capacity, the owner of hydro stations on the Waikato River has no plans for big expansion in the next five years, Mr Heffernan says. "We are looking at smaller things."

"We are not in the position of wanting to build fossil fuel plants."

Geothermal, wind and small-scale hydro schemes were planned.

TrustPower

New Zealand's smallest generator owns 33 small hydro electric generators around the country. It also owns the largest windfarm, in Manawatu.

A 60-megawatt capacity hydro station, at Dobson on the South Island's West Coast, is TrustPower's only planned expansion project.

Feature: Electricity

Energy Efficiency and Conservation Authority