Completed in May 2004, the run-of-river project was built around existing infrastructure that diverts water from Wainisavalu Creek to Lake Monasavu for use by the 80MW Wailoa hydroelectric station – initial construction of this infrastructure provided for the future addition of a micro hydroelectric station on the diversion pipeline. To better manage water flows, a 1.5m adjustable gate has been added to the existing diversion weir.
The powerhouse structure contains two horizontal Francis turbines, each generating enough power to supply around 10,000 Fijian homes. The value of this energy offsets diesel generation fuel costs of over FJ$3M per annum, equating to an emission saving of around 12,000 tonnes of CO2.
The scheme required an innovative approach to design and construction to overcome the challenges of a remote location, in particular the rough access roads, high rainfall and total lack of mains electricity, telephone and internet facilities.
MWH provided detailed design, equipment, procurement, construction supervision and commissioning services for the scheme, which now provides around 4% of Fiji’s energy needs.
In June 2005, the scheme negotiated the world’s first bank-intermediated carbon credit transaction, securing a deal with the Netherlands-based international bank ABN Amro for the purchase of 100% of the Certified Emission Reductions (CERs) created from the project.
Construction work
An extensive environmental impact report was carried out prior to construction of the project, and it was found that the scheme would have no forseeable negative impact on the environment, mainly due to the fact that the project utilises existing structures, existing water flows are not impacted, and the site’s remote location.
An extensive stakeholder consultation was also undertaken prior to construction. The project is built on acquired Native Land by the state, and although no landowners were involved, consultation was undertaken with the Native Land Trust Board, with positive results. Fijian protocol was also observed by presenting a traditional yaqona ceremony to the original owners of the land at Wainikasou and where the associated transmission line was constructed to use connect to the Fuji Electricity Authority grid.
For further information, visit www.pacifichydro.com.au
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