Semiconductor History | 中寮超高壓開閉所, 南投 — The Switchyard Seven Kilometres From the Epicentre

Taiwan generates much of its electricity in the south and consumes much of it in the north, and in 1999 nearly all of that power crossed the middle of the island through one set of busbars in the hills of 中寮鄉, 南投縣.

The 車籠埔 fault ruptured at 01:47 on 21 September 1999, about seven kilometres from them.

台電 calls the site 中寮超高壓開閉所, a switchyard rather than a substation, though contemporary press and Wikipedia both often print 變電所 instead. The distinction matters less than the function: this is where 南電北送, the southward-generated power sent north, actually turned the corner.

The Ministry of Economic Affairs' own twentieth-anniversary account of that night records 622 transmission towers and 17 substations damaged across the island.

Among the casualties was tower 203 on the 345 kV 中寮–龍潭 line, and the switchyard itself.

6.49 million households lost power, which the Ministry describes as the most severe outage in the country's history.

The reason this belongs in a chip history is that 新竹科學園區 lies 105 kilometres north of the epicentre.

Its fabs barely shook. They stopped anyway, because a wafer fab is a building that draws power at industrial scale and cannot be paused politely.

Rationing ran into weeks rather than days. 台電's deputy general manager 蔡志孟 recalled in 2024 that island-wide restrictions were not lifted for two to three weeks.

What the utility did afterwards is visible only if you know where to look.

The steelwork above ground had mostly held; the foundations under it had not, so new mountain towers were rebuilt on deep foundations excavated past fifteen metres and seated at least two metres into firm ground, against the three to six metres that had been normal.

Site investigation went from one borehole per tower to three.

A third 345 kV trunk was run between 嘉民 and 龍崎 and completed in 2002, so that the north–south link stopped being a single argument that the island could lose all at once.

There is nothing here to visit. The switchyard is closed infrastructure on a hillside, and no freely licensed photograph of it exists.

The photograph instead shows 中寮鄉公所, the township hall roughly a kilometre and a half away, sharing its block with the township library and council: the nearest public building to the point where the grid came apart.

Photo: Shxpeng, CC BY-SA 3.0, via Wikimedia Commons; USGS, public domain, via Wikimedia Commons.