THPC plans to expand the 210-MW Theun-Hinboun hydroelectric project in Khammouan Province, which was completed in 1998. The expansion project includes a 220-MW addition to the Theun-Hinboun power station, plus a 60-MW power plant, a six-kilometer headrace tunnel by tunnel boring machine, and a new 70-meter-tall roller-compacted-concrete dam on the Nam Gnouang River, a tributary of the Nam Theun. (HNN 3/18/08)
Under a 5 million euro (USS$7.3 million) contract, Sweco is to provide design review, contract management, and construction supervision of the project. In June 2006, Sweco was chosen to perform a feasibility study and develop tender documents for the expansion.
The new dam, 20 kilometers upstream from the existing Theun-Hinboun Dam, is to create a reservoir to regulate river flows into the Theun-Hinboun headpond, increasing power output in the dry season. The expansion also includes a 900-meter penstock and transmission line.
The Lao government is the largest investor in the US$500 million plant with a 60 percent stake in THPC, which is developing the project. GMS Power, a subsidiary of Thailand's M.D.X. Co. Ltd., has a 20 percent stake and Nordic Hydropower, a partnership of Swedish and Norwegian state-owned utilities Vattenfall and Statkraft, owns the rest.
Electricity Generating Authority of Thailand (EGAT) signed a memorandum of understanding with THPC for supply of power from 2012. State-owned EGAT is to pay an average price of 1.82 baht (5 US cents) per unit for 30 years from 2012.