FAQ – Power Generation

The studies say that the power station will operate for 8000 hrs per year, but dry season flow could be low, so how can there be such a high plant utilisation?
Why not use XPK as the HPP site?

DSHPP generation has been modelled using the long term flow record modified to account for the storage impact (benefit to generation) of the large Chinese dams upstream. The studies demonstrate that DSHPP will have a utilisation factor of 89% of its maximum capacity. This high utilisation factor (compared to most hydros) is because DSH has been optimised to have a relatively consistent generation profile through both dry and wet seasons. The hydrological studies show that mean dry season flow for generation will be in excess of 1,000 cumecs on average. The net head for generation is highest during the dry season, which means power output (in MW) is also high.

The Hou Xang Pheuak spans several hundred metres in width over several different sub-channels, and has always been considered impractical to develop for hydropower since the first major study carried out for the Mekong Secretariat in 1994. Issues include that the area of inundation would be substantially higher due to the topography and the overall channel width, that the backwater effect would potentially impact Don Det and other more populated areas (which Don Sahong does not), and that water levels downstream at the Hou Sahong inlet would be lower and problematical to resolve.

What other hydro developments are there likely to be on other branches near the site?
Will the Don Sahong Project operate as a peaking hydropower station?

Other hydro schemes have been considered in the past in other branches of the Mekong near the project site. However there is a finite amount of water available through the area as a whole, and it would not be economically viable to build more than one hydro station in the Siphandone area. The previously considered Thakho scheme (near the Phapheng Falls) was discounted for this reason, and similarly there are no proposals for other hydro stations on other branches in this part of the Mekong River.

No. The station is run-of-river. There is insufficient water storage for the station to operate in peaking mode.