谷關

Guguan Power Plant is located along the Dajia River in Heping District, Taichung City. It is one link in the Dajia River hydroelectric cascade, operating together with the Techi, Tianlun, Ma'an, and Qingshan plants in a series of stepped hydro facilities.

Guguan Power Plant broke ground in 1957; its first two units were completed in 1961, with the remaining two following in 1966. Typhoon Aere and the July 2004 flood severely damaged its underground powerhouse, and it took roughly four years of repair before all four units returned to service in October 2008.

谷關 (Hydro) currently reports a net generation of 21.2 MW across 4 unit(s), against an installed capacity of 217.6 MW (9.7% 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.