Geothermal energy resources of Jizan, SW Saudi Arabia

• Jizan geothermal site characterized by high heat flow (200 mW/m2).
• This investigation indicates a high temperature geothermal system.
• Both conduction from mantle and radiogenic heat from the granites are driving forces.
• Seismic and resistivity survey indicate presence of two thermal reservoirs.
• Minimum of 134 × 106 kW h electricity that is available from this site.

Jizan geothermal province has evolved over an oceanic ridge slice which is under plated a thin continental crust. The area is characterized by high heat flow and high geothermal gradient and hosts several thermal and warm springs whose chemistry indicates a high temperature reservoir within the granites. The geophysical data indicated that the thermal fluids are fault controlled. The residence time of the fluids, estimated based on 14C, is about 33 kilo years. Oxygen isotope shift suggests that the reservoir temperature is around 220 °C. It is estimated that the province can generate electricity of the order of 134 × 106 kW h which can be effectively utilized to meet future fresh water demand and save CO2 emissions by decreasing the domestic oil and gas consumption.