New Plymouth Power Station
Encyclopedia
The New Plymouth Power Station (NPPS) was a 600 MW thermal power station
at New Plymouth
. Located at Port Taranaki
, it was dual fuelled on natural gas
and fuel oil
.
. Initially, fuel for this power station was to be coal, barged up from the West Coast
, and the Port Taranaki
site was chosen ahead of one at Wanganui
. During early stages of the project, the Maui gas field
was discovered off Taranaki. The plant design was changed to be dual fuel on either natural gas or heavy fuel oil.
The first unit was commissioned in February 1974, with the fifth unit coming on line in 1976. For the first few years, the plant ran on raw Kapuni
gas, converting to Maui gas in 1979.
The fuel oil capability was decommissioned in 1991, and reinstated in 2003.
Plant operation generally decreased from 1999, after the more efficient Otahuhu
combined cycle
power station was commissioned. However, the New Zealand power system derives over 60% of its electricity supply from hydro power stations and depends heavily on rainfall. NPPS has often played a vital role in dry years (such as 2001 and 2003), when hydro lake inflows were insufficient to meet demand.
Discovery of asbestos
, not in an asbestos register, in thermal insulation during 2007 led to the decision by Contact Energy
to close the power station.
In May 2008, one 100 MW unit (unit 3) was temporarily recommissioned. This was in response to a nation-wide electricity generation shortfall resulting from low hydro lake levels. This unit was shut down for decommissioning in December 2008.
The plant has been owned and operated (in turn) by NZED, NZE, ECNZ
and Contact Energy
.
of Newcastle, UK.
The boilers are balanced draught with tilting burners mounted in the corners of the furnace. Each boiler produces 376 tonnes/hour of steam at 120 bar and 538°C, with one stage of reheat to 538°C.
The steam turbines are 3000 rpm single-shaft, three-cylinder (HP, IP and LP) design, with six stages of feed heating. Condenser is a two-pass tubed design, using seawater as the coolant. The generators are two-poled, hydrogen cooled.
Condenser cooling is seawater, with a flow of 12,000 tonnes/hour for each unit.
The chimney is 198 m high, and contains five flues.
Thermal power station
A thermal power station is a power plant in which the prime mover is steam driven. Water is heated, turns into steam and spins a steam turbine which drives an electrical generator. After it passes through the turbine, the steam is condensed in a condenser and recycled to where it was heated; this...
at New Plymouth
New Plymouth
New Plymouth is the major city of the Taranaki Region on the west coast of the North Island of New Zealand. It is named after Plymouth, Devon, England, from where the first English settlers migrated....
. Located at Port Taranaki
Port Taranaki
Port Taranaki is located at New Plymouth, New Zealand. It is the only deep water port on the west coast of New Zealand, and is owned by the Taranaki Regional Council...
, it was dual fuelled on natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...
and fuel oil
Fuel oil
Fuel oil is a fraction obtained from petroleum distillation, either as a distillate or a residue. Broadly speaking, fuel oil is any liquid petroleum product that is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, except oils having a flash...
.
History
The power station project commenced in the 1960s, to meet rising electricity demand in New ZealandNew Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
. Initially, fuel for this power station was to be coal, barged up from the West Coast
West Coast, New Zealand
The West Coast is one of the administrative regions of New Zealand, located on the west coast of the South Island, and is one of the more remote and most sparsely populated areas of the country. It is made up of three districts: Buller, Grey and Westland...
, and the Port Taranaki
Port Taranaki
Port Taranaki is located at New Plymouth, New Zealand. It is the only deep water port on the west coast of New Zealand, and is owned by the Taranaki Regional Council...
site was chosen ahead of one at Wanganui
Wanganui
Whanganui , also spelled Wanganui, is an urban area and district on the west coast of the North Island of New Zealand. It is part of the Manawatu-Wanganui region....
. During early stages of the project, the Maui gas field
Maui gas field
The Maui natural gas field is the largest gas, natural gas condensate and oil field in New Zealand, producing nearly three-quarters of the country's hydrocarbons, as well as providing energy for electricity generation. It is located in the Tasman Sea, 35 km off the coast of Taranaki and to the...
was discovered off Taranaki. The plant design was changed to be dual fuel on either natural gas or heavy fuel oil.
The first unit was commissioned in February 1974, with the fifth unit coming on line in 1976. For the first few years, the plant ran on raw Kapuni
Kapuni
Kapuni is a small hydrocarbons field and drilling site in the North Island of New Zealand. It is located within a dairy farming area in Taranaki, south of New Plymouth....
gas, converting to Maui gas in 1979.
The fuel oil capability was decommissioned in 1991, and reinstated in 2003.
Plant operation generally decreased from 1999, after the more efficient Otahuhu
Otahuhu Power Station
The Otahuhu power station site holds two plants; Otahuhu A and Otahuhu B . The station is owned and operated by Contact Energy.- Otahuhu A :...
combined cycle
Combined cycle
In electric power generation a combined cycle is an assembly of heat engines that work in tandem off the same source of heat, converting it into mechanical energy, which in turn usually drives electrical generators...
power station was commissioned. However, the New Zealand power system derives over 60% of its electricity supply from hydro power stations and depends heavily on rainfall. NPPS has often played a vital role in dry years (such as 2001 and 2003), when hydro lake inflows were insufficient to meet demand.
Discovery of asbestos
Asbestos
Asbestos is a set of six naturally occurring silicate minerals used commercially for their desirable physical properties. They all have in common their eponymous, asbestiform habit: long, thin fibrous crystals...
, not in an asbestos register, in thermal insulation during 2007 led to the decision by Contact Energy
Contact Energy
Contact Energy Limited is a New Zealand electricity generator, natural gas wholesaler and electricity, natural gas, and LPG retailer.The company is the second-largest electricity generator in New Zealand , generating 24 percent of New Zealand's electricity in the year ending 31 December 2009, and...
to close the power station.
In May 2008, one 100 MW unit (unit 3) was temporarily recommissioned. This was in response to a nation-wide electricity generation shortfall resulting from low hydro lake levels. This unit was shut down for decommissioning in December 2008.
The plant has been owned and operated (in turn) by NZED, NZE, ECNZ
Electricity Corporation of New Zealand
The Electricity Corporation of New Zealand Ltd is a New Zealand state-owned enterprise formed on 1 April 1987, as a transition entity in the process of deregulating the New Zealand electricity market...
and Contact Energy
Contact Energy
Contact Energy Limited is a New Zealand electricity generator, natural gas wholesaler and electricity, natural gas, and LPG retailer.The company is the second-largest electricity generator in New Zealand , generating 24 percent of New Zealand's electricity in the year ending 31 December 2009, and...
.
Plant
The power station comprised five identical units, each rated at 120 MW. The boilers were provided by ICL of Derby UK, and the steam turbines were by C A ParsonsC. A. Parsons and Company
C. A. Parsons and Company was a British engineering firm which was once one of the largest employers on Tyneside.-History:The Company was founded by Charles Algernon Parsons in 1889 to produce turbo-generators, his own invention. At the beginning of the Twentieth Century, the company was producing...
of Newcastle, UK.
The boilers are balanced draught with tilting burners mounted in the corners of the furnace. Each boiler produces 376 tonnes/hour of steam at 120 bar and 538°C, with one stage of reheat to 538°C.
The steam turbines are 3000 rpm single-shaft, three-cylinder (HP, IP and LP) design, with six stages of feed heating. Condenser is a two-pass tubed design, using seawater as the coolant. The generators are two-poled, hydrogen cooled.
Condenser cooling is seawater, with a flow of 12,000 tonnes/hour for each unit.
The chimney is 198 m high, and contains five flues.