Jan 10 - Press, The; Christchurch, New Zealand

TrustPower is planning what is believed to be the first big New Zealand wind farm sited by a working hydro power station.

The listed power generator and retailer has announced plans to build a wind farm of up to 300 megawatts (MW) at Lake Mahinerangi, about 40km west of Dunedin.

The farm site is near TrustPower's multi-station Waipori hydro scheme, which uses Lake Mahinerangi's water to generate about 80MW of electricity.

The firm says a 300MW farm would create a $500 million investment in the region. The farm would be built in 100MW stages, each enough to power more than 50,000 average households.

TrustPower spokesman Graeme Purches told BusinessDay yesterday that the synergies between wind and hydro made the project an exciting one.

"It's the first wind farm proposal that is going to be right beside an existing hydro scheme. When you have both, you have great peaking capacity.

"They work hand-in-hand beautifully. This one to us makes so much sense because of the existing scheme, we've got everything up there already -- transmission lines, existing office up there, staff on site," he said.

Resource consents would be applied for later this year, subject to satisfactory engineering, environmental and wind monitoring results, and the farm could be working within two years.

Monitoring had shown the area could be a world-class installation like TrustPower's Tararua wind farm, now regarded as the best- performing commercial scale wind farm in the world, Purches said.

Chief executive Keith Tempest said the farm would provide improved security of supply for Dunedin and other local power consumers during winter and other peak demand periods.

"The ability to retain water when the wind is blowing for use when it is not, plus the availability of added peaking capacity provided when both resources are available, would give the best of both worlds in terms of sustainable generation."