石門

Shihmen Power Plant is attached to the Shihmen Reservoir in Daxi District, Taoyuan City. It is the hydroelectric component of Taiwan's first major multi-purpose reservoir, which also serves irrigation, water supply, flood control, and tourism functions.

Shihmen Power Plant broke ground in 1954 and was completed in 1964, with two 45,000-kW vertical Francis turbines making up its 90 MW capacity. It was originally run by Taipower on behalf of the Water Resources Agency and only formally transferred to Taipower's own management in 2002. Reservoir silting later forced an 11-year shutdown, and the plant resumed generation only in 2015 after a desilting upgrade was completed.

石門 (Hydro) currently reports a net generation of 23.3 MW across 2 unit(s), against an installed capacity of 90 MW (25.9% utilization).

Hydro plants can start or stop within seconds to minutes, making them one of the grid's fastest tools for frequency regulation and peak-shaving. The pumped-storage plants around Sun Moon Lake (Mingtan, Daguan) pump water uphill using off-peak electricity and release it to generate during peak demand, effectively acting as large-scale energy storage. Output is highly dependent on rainfall and reservoir levels.

Hydropower was Taiwan's earliest form of electricity generation, with several plants dating back to the Japanese colonial era. Because most viable river sites have already been developed, hydro capacity has grown little in recent decades and its share has been diluted by the rapid expansion of gas and solar. Its low-carbon, fast-dispatch characteristics nonetheless keep it strategically important for grid stability as variable renewables expand.