Wairakei Powerstation Discharges
Annual Conference
❄
Contact Energy’s geothermal power station at Wairakei, located 10km north east of Taupo, has resource consent to extract up to 245,000 tonnes per day of geothermal fluid from the Wairakei geothermal fields. Disposal of this fluid after processing for power generation and heat extraction has potential to create a number of environmental effects.
The first generating station was constructed in the early 1950’s. At that time all geothermal fluid was discharged either directly (steam condensate from the turbines) or indirectly (separated geothermal water from separators) via local hot streams to the Waikato River. As a result of the environmental and reservoir management impacts this practice became unacceptable. Over a number of years, processes to mitigate operational impact on the river have been continually investigated, developed and implemented. These processes include physical management techniques, such as disposal through reinjection, and water treatment, such as use of a tubular biofilm reactor that uses chemolithoautorophic microbes to reduce sulphide concentrations.
By combining these processes Contact Energy has significantly reduced the impact that operations at Wairakei have on the Waikato River.