Environmental Accounting of Hydropower Construction in Upper Mekong River: An emergy Perspective

To meet surging energy demand, many countries have embarked on hydropower program to achieve renewable electricity production. However, environmental impacts of dam construction, such as landform changes and uneven sediments deposition, have made hydroelectric project a controversial issue. In this study, the long term ecological cost was taken into consideration for hydropower construction evaluation based on emergy method. Mekong River, as an international river, has attracted growing concern for the large-scale hydropower development on it. In this paper, Manwan dam, located in fragile region of upper Mekong River, is taken as a case study. The material and energy flows of hydropower system are evaluated on a common basis from a thermodynamic perspective. Emergy-based indicators are used to figure out beneficial contribution of hydropower and environmental pressure of dam construction. Compared with other traditional energy suppliers, the results show that Manwan hydropower exerts small stress on local ecosystem with a high efficiency of power generation.