Each day of the field trip, a series of video clips are taken which record the experiences that the LEARNZ Teacher is having on your behalf. During the field trip, links to video clips will appear on this page. Each link will have a caption to guide students to look carefully at the video. Teacher notes will be available in the Teacher Share section of the website.

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w01-four-new-wairakei-field-wells.wmv (1.9mb) You are with Donald talking with Sam Pook about four new steam wells at the Wairakei Steam Field.

  • What are the names of these wells?
  • How deep are they?
  • How far apart sideways are these wells where they connect with the steam underground?

w02-steam-pipes.wmv (1.2mb) New pipes are sitting waiting to be welded together to make up the steam pipes.

  • What are the pipes made from?
  • How does the magnetite layer deposited on the inside by the steam help the pipes?

w03-well-head-to-flash-plant.wmv (1.9mb) Well 244 is shiny clean and almost ready for action. Sam describes the parts that make up the well head.

  • What is the pressure of water and steam coming up through the bore?
  • How much water and steam comes up per hour?
  • What is the purpose of the valve on top of the well head?
  • What percentage of water is there?
  • What is the temperature of the water when it comes up through the well head?

w04-flash-plant-number-twelve.wmv (1.3mb) This flash plant is just down from the well head.

  • What is the pressure of water and steam when it enters the Flash Plant?
  • What is the pressure inside the larger vessel?
  • What happens to the steam?
  • What happens to the water? (see next video)

w05-silencer-for-flash-plant-twelve.wmv (2.3mb) This silencer is an impressive site and plays an important part in the management of high pressure waste and steam on the steam field.

  • What pressure does water have entering the silencer?
  • What pressure does the water drop down to?
  • Why is the silencer so necessary?

w06-audioconference-location-wairakei-field.wmv (1.0mb) Sam Pook answered questions today at a site overlooking steam, pipes and well heads.

  • What is Sam’s job with Contact Energy?
  • Where is the audioconference being held?

w07-drill-rig-city.wmv (1.9mb) Meet Eddie manager of this drilling project for Contact Energy. This drill rig is part of a temporary small town.

  • How many truck loads were required to transport the rig to this site?
  • How many people are working on this site?

w08-tour-of-wk248.wmv (3.2mb) After a 10 minute induction, Eddie takes you on a tour of the drill site.

  • What’s the name of this site?
  • How far down has the drilling gone?
  • How far down do they expect to drill?
  • What is the name given to the ‘pipe’ that is drilled down into the ground?
  • What travels down the inside of the hollow drill string?
  • What’s the purpose of the drilling mud?
  • How much would a larger PDC (Poly Diamond Crystal) drill bit cost?
  • What is the purpose of the drilling mud system?

w09-tightening-joins-on-the-drill-string.wmv (2.3mb) You are on the drilling platform of the rig. The driller has asked for the joins in the drill string to be checked. Stand back!

  • What is the name of the device that holds the drill string firm while the joints are tightened?
  • What grips the drill above and below the joint?
  • What is used to tighten the joints?


t01-intro-to-the-wairakei-power-station.wmv (2.4mb) Chris Morris is a mechanical engineer at Wairakei and is responsible for steam turbines at the Power Station. Chris takes you on a quick tour of the power station from the outside.

  • The steam pipe has a loop that goes up in the air before it heads into the power station. What is the loop called?
  • How many turbines in Station A and how many Mega Watts (MW) does each produce?

t02-tour-through-station-a.wmv (2.3mb) Chris Morris takes Donald for a tour of the first power station to be built at Wairakei.

  • What does the red represent on the turbine?
  • What does the green represent?

t03-generator-rotor.wmv (1.6mb) Chris shows Donald a generator rotor taken out for maintenance.

  • Where does the DC power come from?
  • What do the windings in the rotor produce?

t04-turbine-g11-under-maintenance.wmv (1.4mb) From high up on the side of the station you get a good look down into machine G11 with its casing taken off for maintenance. Mechanical Engineer Chris Morris talks you through the components.

  • How long is this machine in length?
  • How much is the rotating mass?

t05-turbine-g11-under-maintenance-2.wmv (1.6mb) Also from high up on the station wall Chris follows the path of high pressure steam as it enters and leaves this mixed pressure turbine. Steam enters the turbine in the middle of its length.

  • What does the steam do as it travels through the diaphragms towards the front of the turbine?
  • What sits between each set of diaphragms?
  • How many stages of diaphragms and turbine blades does the second steam input (through the back set of pipes) have to travel through?

t06-turbine-g11-under-maintenance-3.wmv (0.2mb) The rotor has been taken out of the G11 turbine and is being serviced by two mechanics. (Updated: 6 March, 2006)

  • How many stages of blades are in the front section of the rotor?
  • How many in the rear section?
  • Within the turbine the steam undergoes a pressure drop and a velocity drop.
    • Where does the velocity drop?
    • Where does the pressure drop?

t07-turbine-g11-under-maintenance-4.wmv (1.5mb) Chris gets right inside the turbine.

  • What is the pressure and temperature of the steam when it first arrives in the turbine?
  • What does the curved blade on the diaphragm do to the steam?
  • What is the pressure of the steam at the end of the first eight stages?

t08-turbine-g11-under-maintenance-4b.wmv (2.1mb) Chris is still inside turbine G11 and continues following the path of the geothermal steam. (IP stands for Intermediate Pressure)

  • What happens to the water produced?
  • How many stages are there in the final section?
  • What is the final pressure of steam that exits the turbine?

t09-turbine-g11-under-maintenance-5.wmv (1.1mb) You’re at the front of G11 to see where the machine is controlled.

  • What does the fly weight governor control?
  • How much oil is circulated per minute?
  • What is the purpose of the oil?

t10-turbine-g11-under-maintenance-6.wmv (1.5mb) You’re now looking at a large green box called the condenser that sits underneath G11 and the other Mixed Pressure Turbines.

  • What is condensed into what?
  • How much cooling water is used?

t11-binary-plant-intro.wmv (1.5mb) You’re at the binary plant – called binary because two liquids are used – water and pentane. Here electricity is created from waste hot water from the steam field.

  • How many turbines are there?
  • How many generators?
  • How much electricity is produced?

t12-binary-plant-water-in-water-out.wmv (1.2mb) Pipes bring hot water from the geothermal field and cooler waste water is taken away.

  • What is the temperature of water arriving and leaving at the plant?

t13-binary-plant-water-and-pentane.wmv (1.6mb) Chris explains why pentane is used in the binary plant.

  • Why use pentane?
  • The turbines need high pressure and low temperature. What pressure is the pentane in the heat exchanger unit?

t14-binary-plant-turbines-and-condensers.wmv (2.0mb) Chris shows you the double ended generators – with turbines at each end. A key part of the binary plant is the condenser which returns pentane gas to a liquid.

  • What power is produced by each turbine?
  • For each 8MW of electricity how much heat has to be given off as low grade heat?
  • What temperature is the pentane when it comes out of the turbine (on the way to the condenser)

t15-binary-plant-condensers-and-power-production.wmv (1.8mb) Underneath the condenser structure you get a clear look at the kilometers of tubing that carries the pentane to be cooled.

  • What draws the air up through the tubes?
  • What is the output of the plant on a warm day?
  • What is the output of the plant on a cold day?

t16-binary-plant-reusing-pentane.wmv (1.2mb) The binary plant uses a closed circuit of pentane.

  • What does the 300kW pump do? Returns the pentane to about 12 bar pressure.
  • How much pentane is used in the circuit?

t17-audio-location-thursday-afternoon.wmv (1.8mb) Join Chris, Elizabeth and Donald after the audioconference.

  • What does Chris Morris do here at Wairakei?
  • What does Elizabeth do here at Wairakei?


f01-power-from-power-station-to-grid.wmv (3.2mb) You are on the outside of the fence surrounding the switchyard at the Wairakei Power Station. Electrical Engineer Murray Hill takes you through the power flow from the Power Station supply (at 11,000 volts) to the National Grid (at 220,000 volts).

  • What are the five devices that the power flows through as it comes out of the generator in the Power Station on its way to the national grid?

f02-monitoring-and-controlling-g1.wmv (3.7mb) You are in the control room of Station A at the Wairakei Power Station. Electrical Engineer Murray Hill describes the controls and meters for Generator 1 (G1).

  • What (real) power is being generated at the moment?
  • What current is being generated at the moment?
  • The side panel describes the magnetism that is being produced for the generator in the excitor (a small generator attached to G1).
    • What current is being used in the excitor?
    • What voltage is being used in the excitor?
    • What are the two main components in the generator that must be controlled and how are they controlled?

f03-recreating-pink-and-white-terraces.wmv (2.1mb) You are at a tourist destination near Taupo called the Wairakei Terraces. Geochemist Ed Mroczek talks to Donald about the artificial geyser behind them and what it can tell us about the chemistry of this area.

  • What depth does this water come from?
  • What temperature is the water at that depth?
  • What pressure is the water at that depth?
  • What does the water have in it because of these high temperatures and pressures?
  • When the water comes to the surface the steam is flashed off and the remaining cooler water exceeds the solubility of the dissolved minerals.
    • What is the mineral that is deposited here on these terraces?
    • Why is silica a problem for geothermal power production?

f04-meet-Ed-a-geochemist.wmv (1.4mb) Ed Mroczek is a geochemist with GNS Science. Here he talks to Donald about his role with geothermal power production.

  • What can Ed find out by looking at the composition of the geothermal fluids and gases?

f05-reinjection-of-hot-water.wmv (1.2mb) You’re standing beside a re-injection well where waste hot geothermal water is put back into the ground.

  • What are the two problems that have to be considered when re-injecting waste water back into the ground?

f06-bioremediation-bugs-at-work.wmv (2.4mb) The Wairakei Power Station was built in 1950s by the Waikato River so the river water could be used in the condenser. You are beside the station outlet with Ed Mroczek talking about using bacteria to help purify the water.

  • Which dissolved gas in the water from the power station (the condensate), is Contact Energy trying to reduce?
  • How much of this gas does the condensate have in it now?
  • Where do the bacteria used in the bio reactor come from?
  • What do the bacteria do?
  • How much of this gas does the condensate have in it when it leaves the bioreactor?

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