The Tina River Hydro Development Project (TRHDP) is a National project of Solomon Islands, managed by a dedicated Project Office under the Ministry of Mines, Energy and Rural Electrification, MMERE.
The proposed development is situated on the Tina River, a tributary of the Ngalimbiu River on north Guadalcanal. The Ngalimbiu flows to the Iron Bottom Sound about 15 kilo metres east of the capital Honiara.
The TRHDP is part of a broader initiative called Solomon Islands Sustainable Energy Project, SISEP, and has as its objective the provision of electricity for Honiara from indigenous renewable energy sources(hydro) to provide more affordable and reliable energy options to the capital.
Electricity for Honiara is currently produced solely from diesel-fired thermal generation plant, is unreliable because of the age and limited capacity of the plant, and is the most expensive in the Pacific. Diesel for generation currently costs just over SBD1 million per day.
The TRHDP started with a feasibility study in 2010. After a series of optimisations and two significant geotechnical studies, the current preferred option was identified and confirmed in November 2013.
The proposal is for a single power station with three Francis turbines, each with a capacity of 5 – 8MW. The optimisation of the scheme will be finalised in the first quarter of 2014. Water will be captured by a Roller Compact Concrete, RCC dam, between 35 and 50 metres high, and fed through a 3.5m diameter headrace tunnel, a distance of 3.5 kilo metres to the power house.
Power will be conveyed to the Lungga substation, on the eastern outskirts of Honiara (a distance of approximately 22 kilo metres by twin 33kV transmission lines.
The power station is expected to produce just over 80 GWh in an average hydrological year, which is about the equivalent of Honiara’s current demand. Because of the significant variation between inflows during the wet and dry seasons, there will still be the need for back up thermal generation.
The proposal is for the power scheme to be developed by a private investor either as an Independent Power Producer, IPP/Build Own Operate Transfer, BOOT, project or a PPP with some public equity.
An ESIA is currently in progress. An interim report has identified no significant unforeseen issues, and a draft report for public feedback will be issued in April 2014.
Land owner identification has been completed, and negotiations commenced with the tribal owners of the land required for the project. The local community is very supportive of the project and land acquisition is expected to be completed by the time bids are due.
The International Finance Corporation, IFC, is the Transaction Advisor for Solomon Islands Government. IFC is proposing to issue a Request for Proposal for the BBOT contract in the second quarter of 2014. It is likely that the Power Purchase Agreement will be supported by a World Bank Partial Risk Guarantee, PRG.