Yemen Geothermal Resources

GRC Transactions, Vol. 30, 2006 Yemen Geothermal Resources Anis Abdallah Kamra UNEP Geothermal Consultant ABSTRACT to 2500-2000 m (a.s.l) in the central part, and to 2000-1000 m (a.s.l) in the southern part, Yemen presents a number of high, medium and low III.) Hadramawt-Mahra Uplands (well dissected plateau enthalpy geothermal zones of interest. Some low enthalpy and highlands): highest elevation in this province ranges from resources are exploited by the private sector in tourism activi- about 1500 m (a.s.l) in the west to 1000 m (a.s.l) in the east, ties: hotels, recreation and therapeutic applications. The present and study is clearly high enthalpy geothermal energy, with a view IV.a,) and IVb.) Rub Al-Khali and Ramlat Al-Saba’tayn to electricity generation, in response to the priority accorded (desert and sand seas): elevations in these inland desert areas to establishing whether geothermal power generation in Ye- range from about 900-500 m. men would be feasible. The evaluation of the high enthalpy geothermal resources of the country and the selection of a site of prime interest were the main objectives of the study carried Energy Context out recently by the author as a consultant of UNEP, comple- Yemen’s state-owned Public Electricity Corporation (PEC), mented by field work for the Yemeni authorities. The present under the Ministry of Electricity and Water, operates an esti- article integrates all pertinent geothermal information available and new scientific data recently collected and shows that Yemen represents a good prospect for geothermal resource exploration and feasibility and selects Dhamar area as a high geothermal target. Geographical Setting Yemen is located at the South-west- ern edge of the Arabian Peninsula. The country is bordered by Saudi Arabia in the North, Oman in the East, the Arabian Sea and the Gulf of Aden in the south, and the Red Sea in the West (Figure 1). We can distinguish four principal physiographic provinces as listed below (Figure 2, overleaf). I) Coastal Plains of the Red Sea (Tihama) and Gulf of Aden, II.a) and IIb). Yemen Highlands and High Plateaus (highly and poorly dissected mountainous area and uplands): they may attain 3666 m (a.s.l) in the north Figure 1. Location, urban centres, and communication. 637 Abdallah less than 5 MW, and the sale of generators of 5 MW-20 MW through public offerings. However, plans to privatize the power actions have been delayed indefinitely. Currently, Yemen’s two largest power plants are the 165-MW power station at Ra’s Kanatib, near Al Hudaydah, and the 160-MW station in Al Mukha, south of Al Hudaydah. Long term development of Yemen’s power sector includes a reduction in oil dependence, thus maximizing oil for export. Yemen’s plans include the con- struction of several gas-fired power stations, expansion of the national power grid, and the introduction of renewable energy, such as geothermal energy and solar energy. In the immediate term, the government is promoting large-scale IPPs in order to increase generation capacity by an additional 1,400 MW in near future. Figure 2. Simplified physiographic Map. Geothermal Energy Resources A series of preliminary geothermal investigations have mated 80% of the country’s generating capacity as part of the been carried out over the past three decades both in the national grid. The remainder of Yemen’s electricity is generated Southern and Northern part of the country. National and by small off-grid suppliers and privately-owned generators International groups contributed in these activities. This in rural areas. The PEC distributes electricity in the national led to the definition of preliminary working hypotheses, to grid through two 132Kv transmission systems, one serving the the selection of one or more preferential areas, and to the northern region of Sanaa -Hudaydah -Aden, the other serv- proposal of work programs of surface explorations and fea- ing Mukalla and Hadramawt region (Figure 1). Coverage is sibility studies. All studies presented geological descriptions, reportedly sporadic and inefficient. In 2003, the Government geochemical and hydrological data of the regions concerned. of Yemen estimated that 25% of electricity capacity is lost in The division of the country in two parts in the past did not generation. According to the World Bank, Yemen’s electricity allow the professionals to coordinate their conclusions and shortage is one of the major restraints on economic growth recommendations. In that context, different authors tried, - limiting industrial production and depressing standards of separately, to conclude by a selection of one or more areas living. Traditionally, consumer electricity in Yemen has been as a high priority geothermal zones. highly subsidized. In accordance with IMF reforms, the government of Yemen has recently increased electricity tariffs. The General Geological 2002 reduction in subsidization allowed the PEC to break even Setting for the first time ever. The geology of Yemen Electricity Sector Republic is dominated by the major structures of the In 2002, Yemen’s oil-fired power plants generated 3.1 bil- region: the Red Sea and lion kilowatt-hours of electricity. According to Yemen’s Public the Gulf of Aden. In early Corporation for Electricity (PCE), the country’s generating Miocene times (30 to 25 mil- capacity (810 MW) and electricity distribution network is lions years) the Arabo-Afri- inadequate. Currently, it is estimated that less than one-third can continental crust made of households in Yemen have access to electricity from the of Precambrian crystalline national power grid. Even for those connected to the grid, basement, ruptured along electricity supply is intermittent, with rolling blackout sched- N.NW trending faults in ules maintained in most cities. According to the PCE, Yemen’s the Red Sea region and E-W generation capacity must increase by 1000 MW by 2010, in trending faults in the Gulf order to meet growing demand (up 4.8% over 2001) and to avert of Aden region. Contem- an energy crisis in the medium term. Over the past decade, the poraneously, the basement government has taken steps toward alleviating Yemen’s electric- was uplifted and basaltic ity shortage, including reform, expansion and integration of and rhyolitic intense activ- the country’s power sector through small-scale privatization ity took place building the and independent (private) power projects (IPPs). Plans to Ethiopian and Yemenite restructure the electricity sector were formally laid out in the plateaus (Figure 3). In the Figure 3. General Topographic 1997 Power Sector Strategy, which included a restructuring tertiary, the Red Sea graben Context Red-Sea, Gulf of Aden and of the PCE, planned for 2001. The reform package originally was formed with erosion Rift Valley Yemenite and Ethiopian including the privatization of generators having a capacity of terraces and evaporites and Plateaus. 638 Abdallah exact location and date of occurrence, tectonic effect, international studies based on regional observations suggest that three major seismic zones occur in Yemen: 1. The Red Sea coastal region, north of Ho- deida. 2. The axis Yarim-Dhamar-Sana’a 3. The Transverse structure with respect to Red Sea axis NW-SE to E-W trends. It hence appears that Yemen is far from being a stable continental zone, but is charac- terised by several signs of endogenous activities, with occurrence of both magmatic and thermal convective systems in relation with deep crustal fracturation. Selection of Potential Figure 4. General Geological Map of Yemen. Geothermal Sites coral reef deposition. The General Geological Map of Yemen The most favourable site should benefit of the superposi- (Figure 4) illustrates schematically the presence of Geological tion of all criteria: thermal, volcanic, seismic and tectonic Units. activities. In this report, three types of area (A, B, C) can be distinguished in Yemen: Present Activity Areas of Thermal Activity Only Quaternary (< one million year) and historic volcanic and Hot springs are observed in the basement, in the traps series sismo- tectonic activities occur in Yemen: at the favour of faults or at the contact of different geological formations. In this case, heat manifestation at the surface is Volcanic Activities simply linked with circulation of water towards the surface. Four major zones of recent volcanic activity are known in the country: 1. Sana’a – Amran 2. Dhamar – Rada’a / 3. Sirwah – Marib 4. Aden Volcanic series: Shuqra, Bir Ali, East of Mukalla Thermal Activities Hot springs are known to occur in the following sites: Is- bile, Ali Lissi, East of Dhamar, Hammam Ali, west Dhamar, Demt, Juban La Hammam and Ga’abada, to the south, Al Asurna and Belet Ata’am, east of Hodeida Hot springs are also reckoned to occur in Sukham (Tihama) and Beni Hawan (Sana’a). Seismic Activities Several earthquakes have been reported in Yemen in his- torical times. The most violent occurred in 1057 and partly destroyed towns from Aden to Sana’a. Other earthquakes occurred in 1064 and in 1878 in Dhamar. More recently, earthquakes have been reported in Al Amar (Sa’ada province), in 1975 in Beit Badr (Ibb province) and in Hodeida. In 1983, important seismic events took place in Dhamar area. Although no systematic research was performed in ancient text in order Figure 5. Sana'a Amran Volcanic Field (after Grolier and Overstreet, 1975 to precisely determine the intensity of seismic major events, and Landsat Imagery). 639 Abdallah Area of Recent Volcanic Activity Only In both volcanic districts of Sana’a – Amran and Dhamar – Marib, basaltic flows and scoria cones are observed. They have been enclosed through fissures of roughly E-W direction, and produced basaltic flows only, with no associated silicic prod- ucts. In Sana’a—Amran also called Harra of Arhab—(Figure 5), historic eruptions occurred in the period 400 to 600 A.D.

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