Target temperature exceeded at Dongshan No. 1 geothermal well in Yilan, Taiwan
Yilan, Taiwan (source: flickr/ Emilie Chen, creative common)
Carlo Cariaga
28 Apr 2026
Drilling of Dongshan No. 1 in Yilan County, Taiwan has been completed, with downhole temperatures exceeding the threshold for geothermal power generation.
CPC Taiwan has announced that measurements made at the Dongshan No. 1 geothermal well in Yilan indicate a resource temperature of 180 °C at a depth of 3350 meters. The agency considers the well a success, particularly in the context of the 150 °C target threshold for geothermal power generation.
Drilling of the Dongshan No. 1 well commenced shortly after completion of the Yuanshan No. 1 geothermal well, also located in Yilan County. The Yuanshan well was not quite as successful, only hitting a temperature 150 °C at the 4000-meter target depth. CPC Taiwan decided to no longer deepen the well, as it was considered too costly and risky. However, a rapid increase in temperate near bottomhole was interpreted as indicative of the existence of a nearby upwelling heat source.
Yilan County already hosts three operational geothermal power plants – in Tuchang, Renze, and Qingshui. Both the Renze and Qingshui geothermal fields tap into temperatures of around 180 °C, albeit at much shallower depths (1500 meters for Renze, 2100 meters for Qinghsui).
Whether there is a commercial case for power generation using the Dongshan No. 1 well remains to be seen. It does, however, indicate some maturation in the exploration and prospecting methods employed by CPC Taiwan and Academia Sinica, particularly in light of the results of the Yuanshan No. 1 well. The Government of Taiwan appears to remain resolute in developing its local installed geothermal power capacity, setting a target of 200 MW by 2030 and 2 GW by 2040.
Source: Upmedia
