明潭

Mingtan Power Plant, located in Yuchi Township, Nantou County, is one of Taiwan's largest pumped-storage hydroelectric plants. Operating in conjunction with the Minghu Reservoir and Sun Moon Lake, it pumps water during off-peak hours and generates power at peak demand, serving as an important source of grid flexibility and reserve capacity.

Mingtan was built between 1987 and 1995, using Sun Moon Lake as its upper reservoir and the Mingtan Reservoir as its lower reservoir, with a head of about 380 meters across six pumped-storage units. It ranked among the world's largest pumped-storage plants when completed and remains within the global top ten today, as well as the largest of its kind in Southeast Asia.

明潭 (Energy Storage) currently reports a net generation of -775.5 MW across 12 unit(s), against an installed capacity of 1,602 MW (-48.4% utilization).

This category mainly reflects discharge from battery energy storage systems, which can respond to grid frequency changes within seconds to minutes. It is used for automatic frequency control (AFC) and peak shaving, making it a key tool for grid flexibility as intermittent wind and solar capacity grows. Charging (the mirror-image "storage load") is tracked separately and is not included in this subtotal.

As wind and solar penetration rises, the grid's need for fast-response frequency regulation grows in tandem, making energy storage one of the fastest-growing categories in recent years — typically deployed as containerized battery units near substations or existing power plants. Storage capacity remains far smaller than gas or coal, but its role in maintaining grid stability is becoming increasingly important.