Longyangxia Dam

The Longyangxia Dam is a concrete arch-gravity dam at the entrance of the Longyangxia canyon on the Yellow River in Gonghe County, Qinghai Province, China. The dam is 178 m tall and was built for the purposes of hydroelectric power generation, irrigation, ice control and flood control. The dam supports a 1,280 MW power station with 4 x 320 MW generators that can operate at a maximum capacity of 1400 MW. Controlling ice, the dam controls downstream releases to reservoirs lower in the river, allowing them to generate more power instead of mitigating ice. Water in the dam's 24.7 billion m3 reservoir provides irrigation water for up to 1000000 ha of land.

The dam is composed of its main body and a gravity pier and secondary dam on both its left and right flank. The dam's service spillway contains two 12 m wide gates that discharge water into two 260 m and 280 m long chutes. Downstream discharges are also controlled by a similar single-chute middle outlet and the lower outlet works.

Photovoltaic power station
In 2013 a solar photovoltaic station was built with a nameplate capacity of 320 MWp (Phase I), covering 9 km2. An additional 530 MWp (Phase II) was completed in 2015, covering further 14 km2, making Longyangxia Dam Solar Park, with 850 MWp capacity, one of the largest photovoltaic power stations in the world.

The solar power station is integrated with the hydroelectric power station. The park is coupled to one of the hydroelectric turbines, which automatically regulate the output to balance the variable generation from solar before dispatching power to the grid. This limits the problems connected to variable solar generation while helping to conserve water.