Huntly Power Station facts for kids
Quick facts for kids Huntly Power Station |
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Huntly Power Station in 2005, with the four steam turbine units (two operational as of 2017).
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| Country | New Zealand |
| Location | Huntly, Waikato |
| Coordinates | 37°32′38″S 175°9′10″E / 37.54389°S 175.15278°E |
| Status | Operational |
| Commission date | 1983 |
| Owner(s) | Genesis Energy Limited |
The Huntly Power Station is the largest thermal power station in New Zealand. It is found in the town of Huntly in the Waikato region. Genesis Energy Limited runs the station. This company is partly owned by the New Zealand Government.
The station has five units that make electricity. Three units use coal and gas to power steam turbines. One unit is a smaller gas plant, and another is a large combined cycle gas turbine (CCGT) plant. Huntly Power Station also helps keep the electricity stable in the Northland, Auckland, and Waikato areas.
Contents
How Huntly Power Station Works
Generating Electricity
The power station started operating in stages between 1973 and 1985. It originally had four large units. Each of these units could make 250 Megawatts (MW) of electricity. This meant the station could produce 1000 MW in total.
The chimneys at Huntly are very tall, reaching 150 metres high. Each chimney has two pipes inside, which are 7 metres wide. The plant uses special steam turbines and boilers to create power.
In 2004, the station added a new 50 MW gas turbine plant. Then, in 2007, a bigger combined cycle gas turbine (CCGT) plant was built. This new plant added 403 MW to Huntly's power output. This upgrade cost NZ$520 million. It brought the station's total power capacity to 1453 MW.
In 2007, Huntly Power Station ran at 85% of its full power. It provided a lot of the basic electricity needed for the northern North Island. At that time, it mostly used gas for fuel. However, a dry winter in 2008 meant it had to use more coal.
Over time, some older units were put into storage or stopped working. In 2012, one 250 MW unit was stored. Another 250 MW coal-fired unit was permanently stopped in 2015. In February 2021, a third 250 MW unit was brought back online. This was to help with power needs during a dry period and gas shortages.
What Fuels the Station and How It's Cooled
The four original 250 MW units were built to use two types of fuel. They could burn natural gas from Taranaki or coal from the nearby Rotowaro coal mine. A 10-kilometre long conveyor belt was built to carry coal directly from the mine to the power station.
Before using coal, Huntly mainly used gas from gas fields. But in the 1990s, they switched to coal more often. This was because gas supplies were becoming less available.
The natural gas for the newer units (units 5 and 6) comes from gas fields in Taranaki. A long pipeline, called the Maui gas pipeline, carries the gas 307 kilometres to the station. This pipeline was built in 1979 just to supply Huntly.
The station uses water from the Waikato River to cool its systems. To protect fish and other river life, there are rules about this. The station can only take a certain amount of water. Also, the water returned to the river cannot be warmer than 25°C. These rules mean that on very hot days, the station might not be able to run at full power. Sometimes, it even has to shut down. A new cooling tower was built to help with this. It allows one 250 MW unit to run fully even on hot days.
Sending Power to Homes and Businesses
Most of the electricity made at Huntly Power Station goes to Auckland. Auckland is New Zealand's biggest city, located about 95 kilometres north of Huntly.
Huntly is connected to the national electricity grid through a large substation. From here, six 220 kilovolt (kV) power lines carry the electricity. These lines are:
- A double line that goes to Stratford in Taranaki.
- A double line that goes to Otahuhu substation in Auckland.
- A double line that connects to the Ohinewai switching station.
The Huntly substation also sends power to the local electricity network in the Huntly area.
The Future of Huntly Power Station
Huntly Power Station is the biggest producer of carbon dioxide in New Zealand's electricity sector. It creates more than half of the country's greenhouse gases from making electricity. Because of this, environmental groups have often protested against it.
In 2006, a government report suggested that the plant might need to close by 2015. This was part of plans to reduce climate change. However, the plant still had about 10 years of its planned life left. It was also noted that replacing Huntly's power would be hard. This is because New Zealand's need for electricity grows every year, especially around Auckland. Closing it would also be very expensive.
In May 2012, the Waikato Regional Council allowed the gas and coal units to keep running for another 25 years.
In April 2016, Genesis Energy announced that two of Huntly's coal/gas units would continue to operate until December 2022. The two gas turbine generators would keep running for longer.
The company's chief executive, Marc England, has said that by 2025, Genesis will only use coal in its power units in unusual market conditions. He also stated their goal is to stop using coal completely by 2030.
