Wairakei Geothermal Power Station

"Distributed open client-server architecture is ideal for operating and managing our geothermal power plant installations."
Murray Hill, Generation Engineer - Contact Energy

Murray Hill, Generation Engineer at Contact Energy , discusses their decision to implement Catapult iPower...

"iFIX's distributed open client-server architecture is ideal for operating and managing our geothermal power plant installations, from the steam fields right through to the power station generators. We enhanced iFIX with iPower because of the purpose-built operator dialogs, automated configuration and other useful features like control tagging."

Geothermal Power Stations

Wairakei Geothermal Power Station

Commissioned in November 1958, the this geothermal power plant is situated above a large geothermal system containing water at temperatures up to 240°C. Currently, about 5,000 tonnes per hour of fluid is taken from the reservoir. This is separated into roughly 1,500 tonnes per hour of steam and 3,500 tonnes per hour of water at a temperature of about 130°C. Dry steam is also taken from shallow production wells (up to 500 m depth) and piped directly to the turbines. The steam is directed towards the turbines through the network of pipes around the Wairakei steam field.

Once steam has passed through the turbines it is condensed within 'direct contact' condensers. This cooling system uses water pumped from the adjacent river. After use, the cooling water and steam condensate is discharged back into the river. Gases found in the steam supply are pumped from the condenser and released to the air via gas stacks situated on the power station roof. The hot geothermal water is discharged into a system of drains leading to the river, or it is injected back into the ground.

Ohaaki Geothermal Power Station

Ohaaki geothermal power station was commissioned in 1989. Production wells at Ohaaki are, on average, 1.2 km deep and reach water at temperatures up to 280°C. The most distinctive feature of this station is the 105 meter high cooling tower. Using natural convection, the tower cools the water used to condense the steam as it exits the power turbines. Because little heat or mineralized separated geothermal fluid is discharged to natural waterways, Ohaaki has developed an environmentally friendly reputation.

Poihipi Road Geothermal Power Station

The Poihipi Road power station was commissioned in 1996 and was bought by Contact in January 2000. It is now operated as an integral part of the Wairakei facility and is supplied with steam from the Wairakei geothermal system. Poihipi currently generates around 200,000 megawatt hours (or 200 GWh) per year.

Customer Summary

Location

New Zealand

Customers

-

Total I/Os

8,000

Servers

8 servers distributed over three sites

Clients

8 operational clients plus 3 engineering clients distributed over three sites

LAN

Mixed wire, fiber and 100MB microwave LAN

Software

Windows NT/2000, iFIX 2.6, iPower 2.11

Additional Applications

Proficy Historian

Communications & Remotes

Protocols: modbus over ethernet, Dataterm (Catapult developed OPC driver), Abbey

Media: wire and fiber

Remotes: ABB PLCs, Abbey RTUs, Dataterm RTUs, Merlin Gerin Powermeters

Catapult Software provides leading-edge technology for power industry control systems (HMI/SCADA) and remote equipment communications (DNP3). Since 1991, we have enabled electricity, water, oil & gas utilities, industrial and manufacturing clients around the world to improve the management of essential services and equipment.

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