The Otahuhu power station was a power station site located in
Otara, Auckland, New Zealand. Two plants operated on the site: Otahuhu A (initially open cycle gas turbines, then synchronous compensation) and Otahuhu B (a 404 MW combined cycle). A proposed third station, Otahuhu C, was never built. The stations were owned by
Contact Energy
Contact Energy Limited is a New Zealand electricity generator, a wholesaler of natural gas, and a retailer of electricity, natural gas, broadband and LPG.
It is the second-largest electricity generator in New Zealand (after Meridian Energy), g ...
.
The site was sold by Contact in 2016.
Otahuhu A (OTG)
The first generating units at
Otahuhu were open cycle gas turbine Stal-Laval units, commissioned in 1968. The plant comprised four 45 MW
gas turbine
A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directio ...
units.
In 1978, a further two generating units were added, twin pack units using
Rolls-Royce Olympus
The Rolls-Royce Olympus (originally the Bristol B.E.10 Olympus) was the world's second two- spool axial-flow turbojet aircraft engine design, first run in May 1950 and preceded only by the Pratt & Whitney J57, first-run in January 1950. It is ...
gas turbines.
The Otahuhu A gas turbines were retired from electricity generation in the late 1990s, however they remained in continuous service providing
reactive power to
Transpower NZ, owner of the national grid. In November 2013, the generators were retired from service and decommissioned.
Otahuhu B (OTC)
The
combined cycle plant was commissioned in January 2000.
This
natural gas
Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbo ...
fired plant comprises a
Siemens V94.3A(2)
gas turbine
A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directio ...
in single shaft configuration. The
HRSG
A heat recovery steam generator (''HRSG'') is an energy recovery heat exchanger that recovers heat from a hot gas stream, such as a combustion turbine or other waste gas stream. It produces steam that can be used in a process (cogeneration) or us ...
is unfired triple pressure with reheat. Steam cycle cooling is by a hybrid wet - dry
cooling tower
A cooling tower is a device that rejects waste heat to the atmosphere through the cooling of a coolant stream, usually a water stream to a lower temperature. Cooling towers may either use the evaporation of water to remove process heat an ...
, using sea water makeup.
At commissioning, the plant capacity was 385 MW. In 2005, upgrades to plant components (including the gas turbine compressor) resulted in an increase of plant capacity to approximately 404 MW.
The combined cycle power station ceased generation at the end of September 2015.
Otahuhu C
The Otahuhu C power station was a proposal for a 400 MW combined cycle power station.
Resource consents were granted by Auckland Regional Council for the plant in 2001, but construction never commenced.
In 2002, the
Environmental Defence Society (EDS) appealed the resource consents. EDS argued that the predicted annual emissions of 1.2 million tonnes of carbon dioxide would contribute to climate change via the
greenhouse effect
The greenhouse effect is a process that occurs when energy from a planet's host star goes through the planet's atmosphere and heats the planet's surface, but greenhouse gases in the atmosphere prevent some of the heat from returning directly ...
and that the consent conditions should require complete carbon offsetting by planting of new forests. The
Environment Court
The Environment Court of New Zealand ( mi, Te Kōti Taiao o Aotearoa) is a specialist court for plans, resource consents and environmental issues. It mainly deals with issues arising under the Resource Management Act, meaning that it covers a ...
agreed with the scientific consensus on anthropogenic climate change and concluded that the proposed CO
2 emissions would be an "adverse effect of some consequence". The court declined to impose the forest offsetting condition due to concerns over its "efficacy, appropriateness and reasonableness".
In December 2002, Contact announced it was postponing the construction of the Otahuhu-C plant because of possible future insecurities of gas supply related to the expected depletion of the
Maui gas field. In 2007, Contact said it would still be deferring a decision on the project as it was giving priority to renewable generation. CEO David Baldwin indicated that new generation growth would come primarily from new geothermal capacity. Also the Otahuhu C proposal should wait for the Government's intentions to adopt a market-based
carbon pricing
Carbon pricing (or pricing), also known as cap and trade (CAT) or emissions trading scheme (ETS), is a method for nations to reduce global warming. The cost is applied to greenhouse gas emissions in order to encourage polluters to reduce the co ...
system to become clear. Baldwin still considered the Otahuhu C proposal was the most efficient gas-fired proposal in New Zealand and that it could help reduce emissions if it replaced less efficient coal generation.
The proposed site was sold by Contact in 2016.
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See also
* List of power stations in New Zealand
This is a list of power stations in New Zealand.
The list is not exhaustive – only power stations over 0.5 MW and significant power stations below 0.5 MW are listed.
Power plants in New Zealand have different generating roles ...
References
{{Reflist
External links
Contact Energy website
Natural gas-fired power stations in New Zealand
Buildings and structures in Auckland