Full steam ahead for power station

Shutting down a geothermal power station is not as simple as flicking a switch.

Taupo¯ has been hosting an extra 230 contractors for the scheduled maintenance shut down at Mercury’s Nga Awa Purua Station on Rapids Road.

The power station was shut down on October 27 and all the working parts checked and replaced, if worn. It was back up and running again on November 10.

About $2million was spent on the maintenance work, in addition to lost revenue of up to $250,000 for every day it was out of action.

Contractors poured in from Kawarau, Rotorua, Tokoroa, Hamilton. Specialists from Australia and Japan were also brought in.

‘‘A lot of resources have come from out of Taupo¯ which has been great for the area,’’ Rotokawa Geothermal Field Manager, Mike Stevens said.

Shutting down Nga Awa Purua is necessary to make sure all the equipment was running the way it should be.

Stevens said the next planned shut will be in two years time so all the equipment needs to be safe to operate 24 hours a day, seven days a week for the next two years.

The power station cost $430million to build and boasts the largest single-shaft geothermal turbine in the world. It was completed in 2010.

The shutdown of such a large piece of machinery is complicated. The project started a year ago because replacement components needed to be ordered and built. Planning for the shutdown then took about 30 weeks.

While a shut down of the power station usually takes 20 days, this time it only took 15 days, although no short cuts were taken.

‘‘We know we need to be reliable for the next two years, so while the shut has come in under time, everything has been completed as it should,’’ Stevens said.

‘‘Maintenance on site has been running 24/7 on certain equipment for the last week and a half.’’

The power station is losing a lot of money every minute it is not generating power, but budgeted for.

Stevens said geothermal energy generation is a harsh environment to work in but he believes Nga Awa Purua is the premier geothermal plant in New Zealand. it is