It's big, very big and it crawls by night

The transformer makes slow progress on its five-day trip from the Ports of Auckland south to Huntly.

A crucial part of the country's newest power station has begun its slow, nocturnal crawl from Auckland to Huntly.

For the past two nights, a 255-tonne transformer destined for Genesis Energy's gas-fired power station at Huntly has been making laborious progress from the Ports of Auckland, where it was unloaded last week.

The Australian-built transformer is the first of 16 heavy loads due to arrive in Auckland over the next two months, ready to be put together in a 385MW station being built alongside the existing 1000MW Huntly power station.

State-owned power company Genesis is calling its new station "e3p" - the Huntly Energy Efficiency Enhancement Project. Known as a combined cycle gas turbine, the gas-fired station is about 50 per cent more efficient than the existing Huntly station, which burns either gas or coal.

While the existing station uses a steam turbine to generate electricity, the Huntly e3p uses a gas turbine first and then also converts what would otherwise be waste heat to electricity using a steam turbine.

The transformer's crawl south on its 13-axle, 208-wheel flat deck truck is expected to take five days in total.

The heaviest load is due to arrive next month, when the 377-tonne gas turbine arrives in Auckland.

Genesis has strengthened 27 structures along the route to take the heavy loads, with its biggest job at the Tainui Bridge across the Waikato River at Huntly.

Gas to fuel the new station is due to come from the newly developed Pohokura field in Taranaki and the yet-to-be developed Kupe field.

The new station is due to be commissioned in December next year, meaning it will be useful for providing electricity for the winter of 2007.