水电站建设周期长,是当今水能资源开发速度缓慢的最主要原因之一。在这种情况下,虽然水电站的经济效益高,但是,在要求发电容量高速度投产的条件下,往往倾向于建设火电站,因为其工期要短得多。特别是近些年来,水电站建设的实际周期更大大拉长了,有好几个电站超过了设计规定周期的50～100%。如伏尔加水电站(伏尔加-列宁水电站和伏尔 The long construction period of hydropower stations is one of the most important reasons for the slow development of hydropower resources. In this case, although the economic benefits of the hydropower station are high, under the condition that the power generation capacity is required to be put into operation at a high speed, the thermal power station tends to be built because its construction period is much shorter. Especially in recent years, the actual period of the construction of hydropower stations has greatly lengthened, and several power plants have exceeded 50 to 100% of the design period. Such as Volga Hydropower Station (Volga-Lenin Hydropower Station and Voll