Mothballed Marsden B Plant May Provide Back-up

For Immediate release

24 April, 2003

Mothballed Marsden B Plant May Provide Dry-year Back-up

Electricity generator and retailer Mighty River Power is investigating re-commissioning the Marsden B oil-fired plant as a possible dry-year, back-up generation facility.

The plant has been mothballed since its completion in the late 1970's, as a consequence of the Maui gas development, but current doubts about future supply of domestic fuel, particularly gas, for electricity generation have prompted Mighty River Power to look at using the facility to provide additional capacity when hydro conditions are poor - the original purpose for building Marsden B.

"As a short-term measure to meet the gap created in fuel supply by the run-down of Maui gas, it makes sense to re-look at Marsden B," says Mighty River Power Chief Executive Doug Heffernan. "It's additional capacity that may be able to be brought on-stream by the winter of 2004 so as to provide further security of supply in a dry-year scenario.

"The plant could provide contingency generation capacity even after new gas fields are brought on-stream and new hydro or geothermal projects are available."

Engineering teams have been on-site this week to assess the work required and the time taken to recommission the 250-megawatt oil fired Marsden B power station.

"Initial assessments carried out when we were first given the news earlier this year about the extent of Maui gas run-out indicated that it would take a minimum of 12 months to have the plant fully operational," says Dr Heffernan.

"Clearly that meant it was not a viable option for the current year but we believe it can provide additional dry-year, reserve capacity. Under that scenario we believe it may be economic, and more importantly of national benefit, to fire-up Marsden B."

Assessment of the steps required to recommission the plant will include a review of the condition of the current equipment, what new equipment might be required, a review of the fuel logistics and any resource consent issues. That technical assessment is expected to be completed within six to eight weeks.

"At the end of the process we will know if the oil-fired generation at Marsden B can provide a dry-weather back-up by next winter."

Mighty River Power's decision to investigate firing up Marsden B follows on from its announcement last week of an agreement to assess and develop the geothermal field near Kawerau in partnership with the Putauaki Trust. Initial assessment of that field indicates there may be up to 100 MW available for electricity generation.

Marsden B Technical Description

* 250MW heavy fuel oil fired, conventional thermal power station
* Single steam generator/steam turbine-alternator unit.
* Designed by Mitsubishi Heavy Industries of Japan
* Design commenced 1975
* Mitsubishi Heavy Industries also supplied the major drive train components
* Built by Bechtel
* Marsden B committed to in the early 1970's
* Planned hydro firming role - providing reserve generation for contingency against low rainfall and low lake levels
* Late 1970's oil shock completely altered the economic viability of the station at full output uses 60 tonnes of oil per hour
* Government approval mothballing the station in June 1979
* Mothball process intended to maintain the station in a state ready for commissioning at a later date
* The station remains in this state today

© Scoop Media