The study describes a methodological approach that evaluates the comparative efficiency of construction of export-oriented power plants and transmission lines taking into account the development of power industry in the region and uncertainty (ambiguity) of initial information. At the first stage the authors determine socio-economic effects of each project of construction of export-oriented power plants. With the help of optimization models they choose options that can guarantee the balanced and cost-effective development of the regional electric power system. Then using a simulation model the researchers assess commercial viability of previously selected projects. The article applies this approach for selecting the preferred option of electricity export from Eastern Siberia to China. This study shows that the project of CPP based on Kovykta natural gas with electricity transmission line to Chinese border (near Zabaikalsk) is more preferable one in comparison with other projects (CPP based on Kansk-Achinsk coal in Krasnoyarsky krai; CPP based on coal in the Republic of Buryatia and Zabaikalsky krai (Olon-Shibirskaya CPP; New Kharanorskaya CPP); CPP based on Mugunsky coal in Irkutskaya oblast)