Utilization of geothermal energy in Jordan

Abstract

Jordan is a developing non-producing oil country; the major part of its needed energy is imported from the neighboring countries in the forms of oil and gas, for example, in year 2007 the demand for primary energy reached about 7438 million tons of oil equivalent, with a growth rate 3.5 % which is 1.2% more than the year before and is expected to be much more in the future due to the immigration from the neighboring countries because of the war crisis in the neighboring countries. The cost of this imported energy creates a heavy financial burden on the national economy which reflects on the development plans and the standard living of the people. Therefore it is of great necessity to look for utilizing other energy resources. Investigations and research work carried out by universities staff and the National Energy Research Center have shown evidence that Jordan has a potential geothermal source of energy which can be utilized in producing heat and electricity. In this paper Bouguer gravity data, obtained from a detailed gravity survey that was conducted at the Zarqa Main Zara geothermal field, east of the Dead Sea, are evaluated and combined with other previously obtained geophysical results including aeromagnetic, deep seismic soundings and seismicity. The observed gravity data clearly reflect the complex nature of the structural geology and tectonics of the study region. It revealed the presence of a number of local and regional Bouguer anomalies with different sizes, amplitudes and orientations. These anomalies are interpreted to have been caused by subsurface basic to ultrabasic igneous intrusions located within the uppermost part of the crust, mostly at depths 0.5km-1.5km or shallower. With a density 3.15 g/cm 3 -3.2 g/cm 3 , these have originated from the upper mantle. Travel times of P and S-waves propagating through the study region indicate that some of the subsurface bodies may be in a semi-solid state. The elevated temperature of the geothermal springs of the study area is suggested to be caused by deep water circulation that is facilitated by the permeability of the sedimentary and igneous rocks and both local and regional faults. The hot igneous intrusions remain the major source of heating, though normal geothermal gradient may add slightly to this heating process. The temperatures of the water springs in Zarqa Main- Zara thermal springs are below the boiling point; several applications are suggested to be utilized in the agricultural and industrial fields. Finally, the binary thermodynamic cycle is suggested to utilize this geothermal source in a power plant for generating electricity as the total flow of this thermal water is 25X 10^6 m3/year with an average temperature of 50 degrees centigrade. An approximate estimation of the output power is 3-4 Mega-Watt.