Realistic power and desalted water production costs in Qatar

Abstract

Water security in Qatar is of main concern. Low water pricing in Qatar does reflect the real value of water. The high cost of desalted seawater (DW) calculated in this paper calls for the use of more energy efficient desalting system such as the SWRO system in place of the multistage flash (MSF) and multieffect thermal vapor compression (METVC) methods presently used. Both MSF and METVC use thermal energy of about 270 kJ/m3 and pumping energy of 2–4 kWh/m3. In this paper, the mechanical energy equivalent to the thermal energy supplied to the MSF (or METVC) systems is calculated. When added to the pumping energy, it gives the specific consumed energy of more than 20 kWh/m3, compared to 4–5 kWh/m3 for SWRO system. Qatar’s ground water (GW) is overexploited, depleted, and quality deteriorated, and thus the demand for DW is on the rise, with the more financial burden. Moreover, DW productions mean more air and marine environment deterioration. The water subsidization by the government should be reviewed, and water demand management should be applied. Wastewater should be treated for reuse to decrease the demand on both GW and DW. The calculated costs of DW at different natural gas price are calculated, and compared with the underestimated cost reported by the government.