Clutha Hydro Power the Following 25 Captioned Photos Are from Some Of

Clutha Hydro Power

The following 25 captioned photos are from some of the background pages for the LEARNZ Hydro Power Field Trip web site for Term 2, 2006.

Get much more about hydro power at the Clyde Dam, and the full range of LEARNZ virtual field trips at Next www.learnz.org.nz

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 The historic town of Clyde in Central Otago photographed from the Clyde Dam. Alexandra is under the hills in the middle distance. The Clutha which is NZ's largest river by volume, flows on the right - Image: Heurisko Ltd. Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 The Clyde Dam was built by the Electricity Corporation of NZ Ltd and the Ministry of Works but is now owned and operated by Contact Energy Ltd - Image: Heurisko Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 The construction of the Clyde dam was a continuous process from 1977 to 1989. It is the largest 'concrete gravity' dam in NZ containing 1 million cubic metres of concrete - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 The blasting of a diversion channel through rock was one of the first steps in dam construction - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 The diversion through which the Clutha River flowed during the dam's construction is now sealed off and the water sits quietly - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 The central part of the dam was last to be constructed which included the blocks above the penstocks - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 The progress of construction. See how the left and right abutments, spare penstocks above the river diversion, and dam block behind the new power station have been developed - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 With the Clutha confined to the diversion channel excavations into the bedrock could occur across the valley. The deeper hole near the centre is to expose the rocks along the River Channel Fault Plane - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 This image looks downstream and shows the creation of the diversion channel through, what will later be, the dam itself. The inlets on the left are two of four that will carry the river - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 Removing weathered or shattered rock to leave only solid bedrock in the dam foundations - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 Looking down a series of ladders that leads to the dam foundations. This allows constant monitoring of the dam - Image: Heurisko Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 Attaching the sides of the dam. Notice how all loose rock is removed and the concrete foundations follow the contours of the cliff. Note the hanging walkway and the pattern in the concrete to lock the blocks together - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 The Clyde dam is not a single mass of concrete but a series of separate blocks that are interlocked. The height of each block depends on its position in the dam wall. This view is of the rear wall during construction - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 Only when solid bedrock was reached was concrete poured. The men and machine are vibrating the concrete so it flows and settles, to ensure its maximum strength - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 Reinforcing steel is used to add extra strength to concrete. The amount used varies throughout the dam depending on the role that a block plays - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 Within the dam are walkways that allow inspection and monitoring of the dam. These steps lead up through the major blocks that tie the dam to the sides of the valley.

The stalagmites are from Calcium salts within the concrete. The green is due to algae living on the damp walls and using the lights for photosynthesis - Image: Heurisko Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 Pipes to carry cooling water are laid beneath a mass of concrete poured at foundation level in the left abutment. The concrete is being poured via bucket from an overhead cableway.

Excavators are being used to spread and compact the concrete - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 The pouring of a single block required careful management of the setting temperatures of the concrete, to ensure its strength - Image: Contact Energy Ltd.

Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 This modern switchgear is housed within the powerhouse of the Clyde Dam. The small space it occupies and absence of visible wires is possible because all circuits are insulated with sulfur hexafluoride in the pipe work. Notice also the three phases colour coded red, yellow and blue. Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 • The captioned images so far in this slide slow have come from the Introduction and Construction sections, below. There is much more in the background pages on the web site. Introduction • Why the Clyde Dam is important • Rotor Physics • Dam Data • Faraday's Law and Lenz's law Construction • Stator Physics • Building the Dam and diverting the Clutha • Keeping the Frequency the same River • Producing a Perfect Sine Wave • Excavating the foundations • In The Rotor • Pouring the concrete • In The Stator • Cooling the concrete • In The Turbine Parts of the Clyde Dam • Meeting the Demand for Electricity • The Slip Joint The Physics of Managing electricity • The Spillways, Stilling Pond and Flip Bucket • What is the National Grid? • Aeration Vents and The Dewatering Sluice • AC and DC Converting the Energy "From Water to Wire" • Transformers

• The Energy Laws • The Clyde Switch Room and SF6 Gas • Potential Energy • Switching High Voltages • Potential Energy to Kinetic Energy • Three Phases Electricity • Kinetic to Electrical Energy • Earthing the Power Station The Electricity Generation Equipment • The Penstocks • The Turbine • Scroll Case • Wicket Gates Next • Turbine Runner • The Generators Part of the LEARNZ programme www.learnz.org.nz provided by Heurisko Ltd © Crown Copyright 2006 As well as the preceding images, by the end of the Clutha Hydro Power virtual field trip to the Clyde Dam, the web site has over 100 photos and about 30 video clips.

There are also recordings of 3-6 audioconferences where students from New Zealand schools have their questions answered by electrical engineers and other specialists. A Web Board records further questions about hydro power at the Clyde Dam with answers provided by the experts. A diary is automatically sent from the field to enrolled classes, who also receive 5 newsletters.

There is much, much more . . . http://www.learnz.org.nz/trips06/hydro62.php