Power station gets official opening

Wairakei's new $623 million geothermal power station has been supplying power to thousands of homes since October but it will officially be opened by the Deputy Prime Minister, Bill English, today.

Construction on Contact Energy's Te Mihi began in February 2011 and its two steam turbines produce a total of 166 megawatts, enough to 160,000 homes.

Contact has five geothermal power stations in the Taupo region, accounting for around a third of the company's electricity output.

Te Mihi costs less to run and needs less maintenance than the company's older stations. The Wairakei power station is more than 50 years old.

Te Mihi also utilises modern technology to use the steam more efficiently, producing more electricity per tonne of geothermal steam.

It is also better for the environment, injecting water back into the geothermal reservoir rather than the Waikato River.

Water is reinjected near the edge of the reservoir to minimise cooling of the steamfield.

It also features a network of wells and pipes that can be redirected to certain parts of the power station.

This means the station can be partially shut down for maintenance.

Geothermal steam will be redirected to generation plants that are operating, and in theory the whole site should never have to be shut down at the same time.

Contact chief executive Dennis Barnes said New Zealand was a leader in renewable electricity generation. "Renewable assets on a scale as large as our Taupo steamfield operations are rare around the world. Besides the clear environmental benefits, these long-life assets offer strong cash flow for investors that can be sustained over the long-term."

The Wairakei geothermal resource is the seventh-largest geothermal field by capacity in the world.

"We have employed over 500 contractors, developed homegrown expertise and intellectual property, and contributed approximately $60 million to our New Zealand communities," Barnes said.

Waikato Times