Ngawha Geothermal Power Station Upgrade - Top Energy

Top Energy expanded their Ngawha Geothermal Power Station, which included contracting Ormat to install a new Ormat Energy Converter (OEC) system and a 20 MVA generator. Ergo’s role was to provide an upgrade to accommodate this increase in capacity.

There were some unique challenges with this installation due to the hydrogen sulphide being a harsh, corrosive environment which would affect the new equipment. Consequently protective measures were put in place.

“This has been an extensive job,” comments Kritesh. “It involved a lot of engineering and design to complete the job, as well as interacting with many different parties to ensure the whole job went well.”

Installation details:

• Existing switch room extended
• New 11kV and 33kV indoor gas insulated switchgear (GIS) installed
• Outdoor 33kV circuit breaker removed
• Protection on the existing transformer 11/33kV transformer upgraded
• A second 11/33kV transformer installed in the switchyard
• New earthing transformer installed for the new transformer
• Control cabling tinned to suit the hydrogen sulphide environment
• Two DC panels, two TMS panels and a SCADA panel designed and installed