Geothermal Renewable Energy in Vietnam: A Current Status Overview and Proposing Solutions for Development45242

Geothermal Renewable Energy in Vietnam: A Current Status Overview and Proposing Solutions for Development Van Hiep Hoang(1),(*), Van Tich Vu(1), Trong Thang Tran(2), Xuan Anh Pham(3), Thanh Tung Phan(1) (1) VNU University of Science, Vietnam National University, Hanoi, Vietnam Vietnam Institute of Geosciences and Mineral Resources, Hanoi, Vietnam (3) Vietnam Oil and Gas Group (Petrovietnam), Hanoi, Vietnam * Correspondence: hiephv@hus.edu.vn (2) Abstract: Climate change and energy are two of the biggest challenges in the world and Vietnam today To resolve the mentioned above problem, especially the energy shortage, studying renewable energy systems is becoming necessary This paper investigates the current status of renewable geothermal energy in Vietnam This study focuses on determining the heat source based on geothermometric calculations of K+ - Na+ cations from thermal water in the most 18 potential geothermal sources (in the northern part of Vietnam) in combination with the assessment of groundwater potential by the hydrogeological survey With the deep temperatures of reservoirs are varied from 136oC to 170oC, these geothermal resources can be developed for electricity generation of the capacities from 4.2 MWe to 17.4 MWe Total electric generation capacity from 18 geothermal prospects is estimated to be about 170 MWe Furthermore, the comparison of the policy towards renewable energy and people’s feedback is illustrated Keywords: geothermal energy, renewable energy, Natural resources, Vietnam, development barriers Introduction Geothermal energy - clean and renewable energy comes from the natural heat of the Earth, primarily due to the decay of the naturally radioactive isotopes of uranium, thorium, and potassium (sometimes caused by geological processes or geological phenomenon) On average, the temperature of the Earth increases with depth, about 25oC - 30oC/km above the surface ambient temperature, and the temperature of the earth at 10 km would be over 300°C In the bottom of the continental crust, it is proved that temperatures are to range from 200oC to 1000oC, and the heat is transferred towards the surface mostly by conduction In some areas, the heat flows more easily to the surface, due among others, to intrusion of molten magma from depth, to high surface heat flow due to a thin crust, or to the ascent of groundwater that has been heated Generally, geothermal resources gained above 150oC are produced on electric power generation, the resources have temperature below 150oC are usually used directly in heating and cooling Temperatures from 5oC to 30oC can be used for heat pumps purpose provided both heating and cooling The thermal energy is the immense amount in the world, but only a fraction of it can be utilized in areas where geological conditions permit a carrier (such as water), to ‘transfer’ the heat from deep hot zones to or near the surface, thus creating geothermal resources Geothermal production wells are commonly more than km deep, but rarely much more than km, and most geothermal exploration targets focus on the area where the resource temperature is higher than the average of 300oC, where drilling is shallower and less costly (Vo 1987) Geothermal resources are usually classified in various categories (dry vapor or hot water) depending on the mean annual ambient temperature which they could provide Geothermal being a renewable resource does not emit any greenhouse gas emission and particularly the binary technology which is most suitable for geothermal power development in Vietnam is one of the most environmentally benign energy production technologies Further geothermal power provides baseload electricity at 90 % or above load factor and thus adds to the stability of the electricity grid Renewable energy in Vietnam has been officially studied for several decades, with significant research on assessment of geothermal energy potential being funded by the state budget The study from 1983 by the Geological Department produced a map of national hot water resources, with their respective geothermal potential, allowing the identification and prioritization of the regions which warrant further investigation The study from 1993 by RIGMR was also supported by international organizations (from New Zealand, Italy, and the USA) and identified locations of geothermal potential (Bang, Tu Bong, Hoi Van, Danh Thanh, Mo Duc, Nghia Thang) In 1995, ORMAT, along with PECC1, conducted pre-feasibility studies to select locations for geothermal power plants in the Central region The total capacity was 112.7 MW, consisting of power plants and with a capacity of 55.2 MW planned for the first stage However, due to several difficulties, the research was not continued The study in 2004 by RIGMR concluded that the geothermal energy potential in Vietnam was 340 MW, but that the price of electricity generated was not competitive compared to other sources of energy Because of all these factors, many countries despite having modest geothermal resources like Vietnam strive in harnessing this highly valuable and sustainable source of energy In this paper, group authors going to show an overview observation about the characteristics of geothermal resources in Vietnam, especially in the Northern part of our country Furthermore, we also propose some solutions for potential geothermal power development and management Methodology 2.1 Study potential geothermal sources (in the Northern part of Vietnam) Active fault zones commonly have great effects on fluid transportation in geothermal reservoirs in the northern part of Vietnam During fault movement, all the pores and small fractures that meet with the fault plane become interconnected so that the inner part of the fault, the fault core, consisting of breccia or gouge, may suddenly develop a very high permeability This is evidenced, for example by networks of mineral veins in deeply eroded fault zones in geothermal fields Inactive faults, however, may have low permeability and even act as flow barriers In geothermal reservoirs, the orientation of fault zones in relation to the current stress field and their internal structure needs to be known as accurately as possible One reason is that the activity of the fault zone depends on its angle to the principal stress directions Another reason is that the outer part of a fault zone, the deformation zone, comprises numerous fractures of various sizes Here we present field examples of faults, and associated joints in geothermal fields, and potential host rocks for geothermal reservoirs, respectively We studied several localities of different stratigraphy, lithology and tectonic settings: fault zones in outcrops from some basins Geothermal activity in some basins has long been associated with transport and deposition of sediments, hot mineral springs appearance, making the zone become an important setting for investigating thermal processes Most studies have focused on fluid chemistry, the applicability of geothermal fluid (Cao 2004, Tran et al 2016) Epithermal deposits nonetheless form in zones of high permeability in relatively shallow parts of geothermal systems, along steeply dipping faults, fractures that were clear channels of strongly focused hydrothermal fluid flow (Nguyen et al 2005) 2.2 Analysis of the inquiry result on barriers There are nineteen questionnaires given out to the respondents Among nineteen respondents, eleven ones are working on geology and the best ones are working in energy sectors So, the group can relatively divide the respondents into two groups: geology and non-geology In eleven respondents of the geology group, there are two engineers working for the companies of mining exploration, six researchers working at the research institutes and researchers and teachers at the university Of the eleven geological respondents, there are three people hardly know about geothermal but eight people who have had time to the research related to geothermal from to 20 years Out of eight people with two people who have ever worked with geothermal development in Vietnam Among eight respondents of the non-geology group, there are four respondents working for the institute of renewable energy and other four respondents working for the renewable power company All non-geology respondents are not experienced in geothermal research as well as development The respondents have expertise in geology or energy and have known more or less about geothermal or geothermal energy development so their answers are acceptable The answers to the barriers are classified into categories, so the total percentage of individual barriers in a group is assumed to be a barrier percentage for that category The answers of 19 respondents were aggregated by means of the mean and considered as the result of the survey Results 3.1 Current status of Geothermal energy potential in Vietnam According to the result of surveying a total of 269 water sources covered all the regions of Vietnam carried out by RIGMR in 2005 (Table 1), there are 140 warm spring (52.1 %) and 84 hot spring (31.2%), 41 very hot (15.2 %) and are extremely hot (1.5 %) The geothermal resources have been distributed following the geographic areas in Vietnam territory (Nguyen et al 2006) The distribution of hot springs as follows: 39.8 % in the northern part, 39.5 % in the central part and 19.7 % in the southern part of Vietnam Table 1: Hot springs classification according to the temperatures and potential areas (Nguyen et al 2006) Temperature grades Areas Northwest Northeast North North- South- plain central central % South Summated by temp grades Warm 35 11 27 52 140 52.1 (30-40 °C) Moderate 38 3 19 20 84 31.2 (41-60 °C) Very hot 2 11 20 41 15.2 (61-100 °C) So hot 0 0 1.5 (>100 °C) Summated by area 79 11 17 42 67 53 269 % 29.4 4.1 6.3 15.6 24.9 19.7 100 The geothermal utilization in Vietnam has been studied and applied in the year of '80s of the end of the last century for agricultural heating (tea, coconut-palm, manioc…) in My Lam (Tuyen Quang province) and Hoi Van (Binh Dinh province) geothermal fields with the satisfactory result However, they are the first pilots in the geothermal utilization and are carried out in a difficult situation of economy and techniques in Vietnam, so there is still much limitation Besides, there are some research and applied projects of geothermal resources in order to maintain the crayfish throughout the winter Up to now, almost all geothermal sources in Vietnam today are only used for direct utilization such as spa, bathing, hot water swimming pools, tourism such as: in My Lam, Quang Hanh, Binh Chau, Hoi Van geothermal resources etc and recently people in Quynh Phu and Hung Ha districts of Thai Binh province have used hot water for warming the fish breeding ponds and warming the chickens and pigs farm in the winter According to the authors' prediction (topographic conditions, economic development potential, investment capacities), geothermal energy in Vietnam can develop for Geothermal power plan (GPP) direction which will be presented in the next section (in the Northern part of Vietnam) 3.2 The most potential geothermal sources in the Northern part of Vietnam Although only the reservoir temperature data is computed by the geothermometers through geochemical surveys for geothermal fields Parameters of geothermal reservoirs are estimated relatively based on geological maps, tectonic structures, and international references The thickness of each reservoir is estimated to be m and the reservoir areas are 2.5 km2 Applying the computing methods for the potential of geothermal energy (Metcalfe 1986) Among 100 geothermal resources, there are 18 ones that can be directly applied to energy applications and can be also developed for electric generation (Figure and Figure 2) The surface temperature and flow rate of geothermal water in the hot spring are used to calculate the natural thermal power that is waste heat if is not applied to human uses The results show that it is 8,960 tons of waste heat annually (Table 2) With the deep temperatures of reservoirs are varied from 136oC to 170oC, these geothermal resources can be developed for electricity generation of the capacities from 4.2 MWe to 17.4 MWe The total electric generation capacity from 18 geothermal prospects is estimated to be about 170 MWe (Figure 2) Figure Location map of geothermal manifestation Numbers in the green cycle symbolizes the sources: 1- Pe Luong, 2-Na Hai, 3- Uva, 4-Pa Thom, 5-Pa Bat, 6-Pac Ma, 7-La Si, 8-Sin Chai, 9-Nam Cai, 10-Lang Sang, 11-Nam Pam, 12-Lung Po, 13-Bo Duot, 14-Quang Ngan, 15-Quang Nguyen, 16My Lam, 17-Nam Ron, 18-Kim Da (Tran et al 2016) This map was modified from the Geological map of Vietnam Scale 1/1.000.000 (Tran 1973) Figure Location map of potential geothermal sources related to the surface geothermal field (Numbers in the green cycle symbolize the sources refer to Figure 1) (Tran et al 2016) This map was modified from the Geological map of Vietnam Scale 1/1.000.000 (Tran 1973) Table Characteristics of potential geothermal sources in the Northern part of Vietnam (Tran 2014) No 10 11 12 13 14 15 16 17 18 Name Pe Luong Pa Thom Uva Na Hai Pa Bat Pac Ma La Si Sin Chai Nam Cai Lang Sang Nam Pam Lung Po Bo Duot Quang Ngan Quang Nguyen My Lam Nam Ron Kim Da Location Surface T(*) Deep T Flow rate Waste heat Achievement temperature with 30oC - output T Criterion energy with 30oC - output T Geothermal energy potential for exploration Electric generation capacity estimation (District, Province) (oC) (oC) (l/s) (KJ/s) (KJ/s) (ton/yr) (1014 KJ) (MW) Thanh Luong, Dien Bien Pa Thom, Dien Bien Dien Bien, Dien Bien Sam Mun, Dien Bien Muong Luan, Dien Bien Muong Te, Lai Chau Muong Te, Lai Chau Phong Tho, Lai Chau Sin Ho, Lai Chau Mu Cang Chai, Yen Bai 53.80 57.00 74.00 78.00 61.50 62.50 54.00 74.00 62.00 53.00 151.00 146.00 161.00 170.00 143.00 147.00 152.00 151.00 162.00 139.00 1.70 0.40 2.53 3.00 0.10 1.20 25.00 5.00 3.00 0.70 205.14 53.63 164.25 666.21 21.41 188.55 3,037.75 1,026.55 465.09 82.12 169.53 45.25 147.49 603.36 18.48 163.41 2,514.00 921.80 402.24 67.46 182.28 48.66 158.58 648.74 19.87 175.70 2,703.09 991.13 432.49 72.53 1.50 2.23 2.36 4.10 2.05 2.88 4.23 2.21 1.72 4.23 4.20 6.20 6.60 11.40 5.70 8.00 11.80 6.20 4.80 11.80 Muong La, Son La 55.50 139.00 0.80 102.24 85.48 91.90 4.10 11.40 Bat Xat, Lao Cai Vi Xuyen, Ha Giang Vi Xuyen, Ha Giang 53.00 71.00 62.00 136.00 181.00 170.00 3.00 1.00 5.00 351.96 192.70 775.20 289.11 171.80 670.40 310.85 207.80 810.90 1.63 2.10 1.80 4.50 17.40 15.30 Xin Man, Ha Giang 56.00 144.00 5.00 649.50 544.70 658.90 1.20 10.40 Yen Son, Tuyen Quang Tan Ky, Nghe An 65.50 57.00 143.00 138.00 6.30 1.00 1,065.70 134.08 934.10 113.13 1,129.90 121.64 1.20 5.40 9.70 9.00 Tuong Duong, Nghe An Total 73.50 163.00 1.00 203.22 9,385.30 182.27 8,044.01 195.97 8,960.93 8.30 51.01 13.80 168.10 T(*): Temperature (Degrees Celsius-C) Direct uses of geothermal energy have been applied in Vietnam where geothermal resources exist (Figure 2) The direct uses take the form of rudimentary traditional systems where communities living in the Northern part of Vietnam have used geothermal energy for various uses These various uses can help local inhabitants in tourism development like bathing, drying of crops, condensation of the steam to harvest potable water and boiling of eggs, to complex systems like district heating, greenhouse heating, and refrigeration In the Northern part of Vietnam, traditional systems are evidenced at Uva, My Lam, Thanh Thuy, Kim Quang Ngan where the local community has been tapping the steam for bathing, spas, ecotourism development A large number of mountain areas in the Northern part of Vietnam include geothermal areas, usually with close links to volcanic activity Annual visitor numbers are considerable, but consist mainly of domestic travelers who visit the geothermal centers on their ‘hot spring pilgrimage’ Many Vietnamese ‘collect’ onsen and travel extensively to discover and experience as many hot springs in their country as possible With the calculated temperature in the Northern part of Vietnam, the exploitation of regional energy for power generation purposes, we should use the Binary Cycle technology to ensure the exploitation of energy from these sources The heat has a low source temperature, but at the same time protects the environment by not discharging hot water 3.2 The inquiry result on barriers 3.2.1 Geothermal power plan (GPP) According to our survey results, both groups (geology and non-geology) agreed that policy and technique issues are the two biggest categories of the barrier For the non-geology group, the biggest category of the barrier is technical issues while for the geology group the biggest one is the policy issues In policy issues, the two groups agreed that national energy policy is the most important, then to the lack of incentives and the lack of investment in research and development Similarly, the technical category of barriers that stand up, the two groups agreed that the biggest barriers are lack of information or experience (general), then the data exploration technology, integration or interpretation (Table and Figure 3) While the geology group responded that the financial issues are major barriers accounted for 21%, the non-geology group responded that they are only accounted for 14% For the legal issues, the geology group’s response is the smallest barrier (13%) but the nongeology group’s response is not the smallest barrier (15%) In general, both groups’ responses are not so different and can serve together by taking the average values Table shows the order of the categories of barriers that stand for geothermal development are technical problems (25%), policy issues (24%), social issues (20), financial issues (18%) and finally to the legal issues (13%) Water 2019, 11, x; doi: FOR PEER REVIEW www.mdpi.com/journal/water From the survey results may be temporarily assessed that the biggest category of barriers that stand with the development of geothermal energy in Vietnam is still technical issues in which the lack of information and experience are the most dominant factor (Table and Figure 4) This is understandable because there has never been any geothermal resource exploration as well as any geothermal power generation in Vietnam so that can allow people to get complete information on the geothermal source and geothermal power plants The policy issues are the 2nd important factor hindering the development of geothermal power In more particular, national energy policy and economic incentives are the most important The 3rd biggest category of barriers that stand on social issues with special emphasis on the lack of specialists The fourth biggest category of barriers is financial and the category of legal barriers is evaluated as the smallest In terms of barriers, here we see the barrier to exploration costs being the biggest (11.5%) The second biggest barriers are the lack of experts (9.8%) and the incentive policy (9.7%) to geothermal development From a total of 28 barriers that stand investigated, there are 15 barriers that stand noteworthy because of a much higher percentage than any of the rest barriers that stand almost negligible Some barriers stand very low, to 0%, suggest that interviewees may not be aware of it The change in the barrier rate from 0% to 11.5% indicates a fairly uniform assessment without focusing on certain barriers This further confirms that there is no geothermal power plant in Vietnam so it is impossible to have a clearer assessment of the certain barriers (Table and Figure 4) Table Degrees of barriers hindering the geothermal power generation development in Vietnam Category of % in all Barriers % in all Policy 24 National Energy Policy 9.4 Lack of Economic Incentives 9.7 Social Legal Fiscal 20 13 18 Lack of R&D Funding 4.8 Domestic Business Protection 0.0 Other policy matters 0.0 Lack of Expert 9.8 Lack of Awareness 3.1 Lack of Knowledge 2.2 Lack of Business Model 3.8 Other Land Uses 1.2 Public Acceptance (PA) 0.1 Other social matters 0.0 Environmental Matters 1.7 Legislation/Business Mechanism 4.1 Lack of Legal Incentives 7.3 Red tape in government 0.9 Other legal matters 0.0 High Exploration Cost 11.5 Low Selling Price 5.0 Technical TOTAL (%) 25 100 No Loan nor Support 0.8 Other fiscal matters 0.6 Lack of Information/Experience 9.1 Exploration Technology 5.3 Data integration or interpretation 5.0 Drilling 2.6 Scaling, Erosion, Corrosion 0.3 Reservoir Management 1.5 Other technical matters 0.1 100 Figure Categories of the barrier to geothermal power generation development in Vietnam Figure Barriers to geothermal power generation development in Vietnam 3.2.2 The ground source heat pump (GSHP) Since there is no GSHP application in Vietnam, almost everyone just understands this system Therefore, the technical category of barriers is considered the largest, accounting for 27%, of which 12% belongs to lack of installation experience The financial category of barriers, though accounting for only 18%, of which installation cost is accounted for 14.7%, is the highest among the barriers Similar to GPP, the social issues here are also considered to be the second-largest category of barriers in which the barrier due to national energy policy accounted for 10.6% In general, as with GPP, there are many barriers to the development of GSHP This reflects that there is no GSHP application in Vietnam until now If there were some available GSHP application, the evaluation of respondents maybe another review Table Degrees of barriers hindering the ground source heat pump installation in Vietnam Category of % in all Barriers % in all Policy 24 National Energy Policy 10.6 Lack of Economic Incentives 6.6 Lack of R&D Funding 4.4 Others 2.5 Lack of Expert 4.8 Lack of Awareness 1.8 Lack of Knowledge 3.6 Social 20 Legal Fiscal Technical 13 18 25 Lack of Business Model 6.8 Others 0.3 Environmental Matters 4.3 Legislation/Business Mechanism 3.1 Lack of Legal Incentives 4.8 Others 0.3 High installation Cost 14.7 No Loan nor Support 3.3 Others 0.3 Lack of Information/Experience 12.2 Lack of hydrogeological info 4.4 Lack of installation technology 7.2 Lack of heat pump makers 4.0 Others TOTAL (%) 100 0.0 100 Figure Categories of barriers to ground source heat pump installation in Vietnam Figure Barriers to ground source heat pump installation in Vietnam 3.2.3 Innovative ideas to remove barriers Preliminary assessment shows that geothermal potential in Vietnam could allow the development Although the intention to build a geothermal power plant has been in place since 1995, so far there have been no factories Why? The barriers that are pointed out in the above investigation may be the answer to this question Because geothermal energy is still quite new, the community and business don’t pay much interest in it, so the government should issue the priority for it first But in order to make the policymaker to understand geothermal and the benefit from the geothermal application, the role of scientists and specialist are very big In order to so, the geothermal projects should be funded because based on that the scientists and specialists will have proof to prove for the effectiveness of the geothermal energy development Emphasizing that geothermal research must work in partnership with scientists from the countries with geothermal development in the world, otherwise investing in geothermal will not be effective and may waste money Encourage brave companies to invest in geothermal energy development, especially for pioneering companies Priority policy must be documented in detail and this policy must be applied effectively through the management levels from central to a local level Parallel with the preferential policies, the government must pay attention to the training of human resources In the immediate future, it is possible to put selected subjects into the teaching program for undergraduate students in geology and in techniques The electricity pricing policy for geothermal energy should also be issued early to make it as a basis for the investors to determine their investment in geothermal energy At the same time, the government also needs to prioritize the purchase of geothermal power by its inherent benefits in comparison with other types of energy including other renewable energy If geothermal law cannot be enacted in the current period, geothermal resources need to be included in the mineral law soon, with the same regulations as for other minerals Of course, it is necessary to refer to geothermal law in countries that already have a geothermal law to make detailed provisions to match geothermal minerals Try to integrate geothermal programs into other socioeconomic research programs if possible Prioritize to allocate the favored capital and credit from the development fund, ODA fund and other bilateral lending funds for geothermal as well as reinforce the human capacity The law on renewable energy needs to be issued soon Because this is a breakthrough step and will make favorable conditions to push up the development and utilization of renewable energy as well as creating the market for renewable energy in general and geothermal in particular to develop Reinforce the manpower by scientific and technological training for geothermal energy through the cooperation projects Push up the international cooperation in science and technology on geothermal energy Conclusions and Discussion The geothermal utilization in Vietnam has been studied and applied in the year of ’80s of the end of the last century for agricultural heating in My Lam (Tuyen Quang province) and Hoi Van (Binh Dinh province) geothermal fields with the satisfactory result However, they are the first pilots in the geothermal utilization and are carried out in a difficult situation of economy and techniques in Vietnam, so there is still much limitation Up to now, almost all geothermal sources in Vietnam today are only used for direct utilization such as spa, bathing, hot water swimming pools, tourism such as: My Lam, Quang Hanh, Binh Chau, Hoi Van geothermal resources etc and recently people in Quynh Phu and Hung Ha districts of Thai Binh province have used hot water for warming the fish breeding ponds and warming the chickens and pigs farm in the winter The total generation capacity of the 18 geothermal sources potential in the Northern part of Vietnam is 170 MWe calculated by the method of calculating the generating capacity on the basis of duality technology The lowest capacity geothermal sources are 4.2 MWe (Pe Luong) and the highest capacity geothermal source is 17.4 MWe (Bo Duot) However, in order to conduct visits due to the exploitation and construction of geothermal power plants, it is necessary to assess the ability according to the geological, technical, and technological design and installation conditions associated with the location of each geothermal source The results of this study open up opportunities for investors and managers on clean energy sources in the future, and it also opens opportunities for the application of geothermal power generation technology currently being popularized 3 Innovative Ideas to develop geothermal energy (Electricity production) base on policies current status: At present, the current energy policy framework in Vietnam does not provide adequate support for developing commercially viable geothermal power projects The unique risk profile of geothermal power plants requires the implementation of some special policy package In order to promote geothermal power plants in Vietnam, it is recommended to implement two policy instruments The first one is a hybrid scheme of capital subsidy and soft loans This scheme will help alleviate the early high-risk profile of the exploration stage of geothermal power development Certain fiscal benefits such as tax break, import duty exemption, land levy exemption of which geothermal power plants are already eligible are recommended being continued However, the effect of these policies will be minimal with respect to the overall economics of the geothermal power plant operation However, they will bring some additional benefits to the potential project developer In addition to the recommendation of the policy package, another important recommendation is to develop a detailed geothermal atlas of Vietnam This atlas when fully completed will be immensely valuable in overcoming the information barrier related to geothermal resources in Vietnam This, in turn, will greatly facilitate in raising the interest among the geothermal power developers around the world Finally, the most crucial aspect of realizing the potential of geothermal power in Vietnam is its effective implementation As Vietnam is now embarking on its journey towards geothermal power development, it is recommended approaching a gradual step by step approach to fully utilize the geothermal power potential Acknowledgments This work was supported by the Domestic Master/Ph.D Scholarship Programme of Vingroup Innovation Foundation and VNU University of Science (Hanoi) through project number KHCN-TB.01T/13-18 References Cao, D.G (2004) Final report of Project “Research and evaluation of the geothermal potential in the Northwestern Plain of Vietnam and It is a prospect for economic and social development” Hanoi: Institute of Geosciences and Mineral Resources, 1, 179 Metcalfe, I (1986) Late Palaeozoic paleogeography of Southeast Asia: some stratigraphical, palaeontological and palaeomagnetic constraints Bulletin of the Geological Society of Malaysia, 19, 153-164 Nguyen, T.M., Tsujimori, T., Itaya, T (2006) Honvang serpentinite body of the Song Ma fault zone, northern Vietnam: a remnant of oceanic lithosphere within the IndochinaSouth China suture Gondwana Research, 9(1-2), 225-230 Nguyen, T.C., Cao, D.G., Tran, T.T (2005) General Evaluation of the Geothermal Potential in Vietnam and the Prospect of Development in the Near Future Proceedings World Geothermal Congress 2005 Antalya, Turkey, 24-29 April 2005, 1-8 Tran, V.T (1973) Geological map of Vietnam Scale 1/1.000.000 General Department of Geology and Minerals of Vietnam Publication, Hanoi Tran, V.T (2014) Northern part of Vietnam Geology of Vietnam; Vietnam National University Press, Hanoi, 1, 908-918 Tran, T.T., Vu, V.T., Dang, M., Hoang, V.H., Pham, H.T., Pham, X.A (2016) Assessing the Power Generation Potential of Geothermal Prospects in the Midland and Mountain Areas of Northern Vietnam VNU Journal of Science: Earth and Environmental Sciences, 32(2S), 225-235 Vo, C.N (1987) Final report of Project “Evaluating geothermal sources serving as the basis for their exploitation and utilization for energy purposes in some prospective areas, Vietnam” Hanoi: Institute of Geosciences and Mineral Resources, 245 pages  ... renewable energy as well as creating the market for renewable energy in general and geothermal in particular to develop Reinforce the manpower by scientific and technological training for geothermal energy. .. Hanoi: Institute of Geosciences and Mineral Resources, 1, 179 Metcalfe, I (1986) Late Palaeozoic paleogeography of Southeast Asia: some stratigraphical, palaeontological and palaeomagnetic constraints... is necessary to refer to geothermal law in countries that already have a geothermal law to make detailed provisions to match geothermal minerals Try to integrate geothermal programs into other