There are more than 4,000 hot spring operators on the island of Taiwan, implying the potential for large geothermal resources. Geothermal exploration can be traced back to the 1970s and there has been the development of two pilot geothermal power plants in Taiwan in the 1980s, with capacities of 280 kWe and 3 MWe, respectively. The former was decommissioned due to funding cut and the latter was abandoned due to a decline in steam production in 1993. Since then, there have been no geothermal power plants in operation. Recently, there has been renewed interested in geothermal energy in Taiwan with the aim of developing renewable energy and reducing the dependence on imported fuels.
Geologically, Taiwan is located in the Pacific Ring of Fire on a convergent and compression boundary between the Philippine Sea and Eurasian Plates. The collision of these two tectonic plates results in frequent earthquakes (30,000/yr), structural complexity and explains the presence of numerous volcanoes and geothermal areas. From west to east, Taiwan can be divided structurally into the Coastal Plain, the Western Foothills and the Hsuehshan Range, West Central Range/Backbone Range, East Central Range/Tananao Schist complex, the Longitudinal Valley and the Coastal Range. The difficulty of geothermal exploration and development is heightened in Taiwan as the geothermal areas are generally found in low permeability metamorphic rocks and in the steep and rugged terrain of eastern Taiwan.
Major geological units of the Island of Taiwan. CR: Coastal Range; LV: Longitudinal Valley; ECR: East Central Range or Tananao Schist complex; WCR: West Central Range or Backbone Range; HSR: Hsueshan Range; WF: Western Foothills; CP: Coastal Plain. From the Central Geological Survey of Taiwan-MOEA
Geothermal Areas of Interest
The Chingshui geothermal field once hosted the first geothermal power plant in Taiwan from 1981 to 1993. After a long period of inactivity, this field is attracting renewed interest with the development of the National Energy Policy (Phase II). It is located in the valley of the Chingshui River, northeast Taiwan. The area has a number of faults, the most important being the Tashi, Hsiaonanao and Hanhsi faults, and Chingshuishi. There are numerous hot springs and fumaroles along the river within the geothermal field. Geothermal production at Chingshui is largely from a fracture zone in the steeply dipping Jentse Member.
The brine is characterized by a high concentration of HCO3− (up to 2768 ppm) and low Cl− (lower than 40 ppm) with pH values between 8.5 and 9.0, and the non-condensable gases are predominantly composed of CO2 (up to 98%).
The geothermal field at the Hongchailin area in Sanshin Township: The area of Hongchailin in Sanshin Township is situated at around the apex of the Ilan Plain south of the Lanyang River. While it’s geothermal gradient was not the most impressive, Hongchailin was chosen as the first geothermal field because of the following reasons:
Unfortunately, details of the subsurface structure poorly known. In order to improve their understanding, nine seismic reflection surveys were conducted. Properties of the rocks reduce the quality of the seismic images in the area. Regardless, they were able to identify that the main fault of the fault system trends W-E and dips to the north, and minor faults were developed at both sides of the major fault
Jinlun geothermal region: The Jinlun geothermal field is located in the southeastern part of Taiwan, which belongs to the southern part of the Backbone Range. The exploration of the Jinlun geothermal region began in the 1980s. High temperature (98 °C) hot springs are widespread upstream and downstream of the Jinlun river suggesting a high geothermal potential. Between 1982–1984, a total of 11 geothermal exploration boreholes were drilled by Industrial Technology Research Institute (ITRI) and Chinese Petroleum Company (CPC). Temperature measurements, surface and borehole geology study, borehole flow tests, and geochemical analyses were carried out. The highest formation temperature recorded was ~190 °C @ 2000 m.
Tatun Geothermal system:
The Tatun geothermal system is located in the northern part of Taiwan is a promising target for geothermal exploration due to the abundance of hot springs and fumaroles associated with young volcanic rocks. The Mineral Research and Service Organization (MRSO) and the Chinese Petroleum Corporation (CPC) conducted extensive exploration efforts at Tatun from the late 1960s until the early 1980s. This work included geologic mapping, geochemical sampling, geophysical surveys, and the drilling of more than 20 exploration wells (> 500m deep) and a large number of shallow (< 500 m) temperature gradient wells drilled by MRSO. The encountered temperatures of 200–300 °C in the Matsao area but the geothermal fluid very acidic. Following the work conducted by MRSO, the CPC drilled three deep exploration wells detailed in the table below.
|CPC-MT-1T||Matsao area||1717m||~ 200 °C||alteration assemblage of epidote, actinolite, and chlorite below 1100 m) indicate temperatures that were reached∼300 °C|
|CPC-SHP-1T||Szehuangtzeping||2 km||~ 160 °C|
|CPC-CSN-1T||Chinshan||2001m||∼103 °C (@300m ∼150 °C total depth|
Shallow geothermal potential
Due to its geological makeup and location, Taiwan is also home to low-high temperature shallow geothermal resources. Recent studies on the application of shallow geothermal include the Investigation of a Liquid Desiccant Dehumidification System in New Taipei City.
Phase I of Taiwan’s National Energy Program (NEP-I) established four directions for future energy programs: energy efficiency, energy usage & energy sustainability, renewable energy development & utilization, and formulation & evaluation of energy technology development strategies. Currently in Phase II there are are a number of focal points including the development of energy policy guidelines and development of the renewable energy industry and accompanying measures. Geothermal energy has been paired with gas hydrates with three main focus areas:
The Taiwan Power Company (Taipower, a state-own organization) aims to increase the installed capacity for renewable generation (including hydropower) to 5,400 MW. This will consist of 1,800 MW of offshore wind power, 1,000 MW of solar power, 600 MW of inland wind power, 100 MW of geothermal power and 1,900 MW of hydropower by 2030.
To achieve these goals, Phase I of the National Energy Program (NEP-I) was established in 2009. Based on the foundational research in NEP-I, the main development goals of NEP-II (started in 2014) includes the development of clean geothermal energy resources.
This concludes our #GeothermalCountryOverview on Taiwan. The first of 10 countries our followers on LinkedIn, Facebook, Instagram, and Twitter chose. Click here to read about the previous 13 countries published.
Guest Author: Jason Fisher
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Sources/ Further Reading
Lu, Y.C., Song, S.R., Wang, P.L., Wu, C.C., Mii, H.S., MacDonald, J., Shen, C.C. and John, C.M., 2017. Magmatic-like fluid source of the Chingshui geothermal field, NE Taiwan evidenced by carbonate clumped-isotope paleothermometry. Journal of Asian Earth Sciences, 149, pp.124-133.
Guo, T.R., Tong, L.T. and Huang, Y.T., 2018. Metamorphic geothermal reservoir characterisation—A case study in the Jinlun geothermal area, Taitung, Taiwan. Geothermics, 74, pp.35-44.
Lu, Y.C., Song, S.R., Taguchi, S., Wang, P.L., Yeh, E.C., Lin, Y.J., MacDonald, J. and John, C.M., 2018. Evolution of hot fluids in the Chingshui geothermal field inferred from crystal morphology and geochemical vein data. Geothermics, 74, pp.305-318.
Dobson, P., Gasperikova, E., Spycher, N., Lindsey, N.J., Guo, T.R., Chen, W.S., Liu, C.H., Wang, C.J., Chen, S.N. and Fowler, A.P., 2018. Conceptual model of the Tatun geothermal system, Taiwan. Geothermics, 74, pp.273-297.
Shih, R.C., Wang, C.Y., Chen, W.S., Wang, Y.K., Kuo, H.Y., Yen, T.C., Huang, C.C., Chang, Y.C., Chung, C.T., Hunag, M.Z. and Chang, Y.F., 2018. Seismic reflection profiling of the first deep geothermal field in Taiwan. Geothermics, 74, pp.255-272
Fan, K.C., Kuo, M.T., Liang, K.F., Lee, C.S. and Chiang, S.C., 2005. Interpretation of a well interference test at the Chingshui geothermal field, Taiwan. Geothermics, 34(1), pp.99-118.
Liang, J.D., Huang, B.H., Chiang, Y.C. and Chen, S.L., 2019. Experimental Investigation of a Liquid Desiccant Dehumidification System Integrated with Shallow Geothermal Energy. Energy, p.116452.
Taiwan Geothermal Association on the geothermal potential of Taiwan http://www.thinkgeoenergy.com/taiwan-geothermal-association-on-the-geothermal-potential-of-taiwan/
Tsanyao, F.Y., 2015. Introduction to the geothermal energy program in Taiwan. In Proceedings World Geothermal Congress (Vol. 2015, pp. 19-24). https://pangea.stanford.edu/ERE/db/WGC/papers/WGC/2015/01066.pdf
Present Status and Future Plans of the Geothermal Energy Master Program of NEP-II in Taiwan. http://pubs.geothermal-library.org/lib/grc/1032306.pdf
Generally geology and Geologic provinces of Taiwan https://www.moeacgs.gov.tw/english2/twgeol/twgeol_generalgeol.jsp
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