SUN MAKING WATER IN THE SAHARA

Is CSP the solution to water poverty in MENA?
Heba Hashem, 24 January 2011 (CSP Today)

"…Countries in the MENA region are facing serious water deficits that are expected to worsen unless major investments are pumped into more sea desalination projects…[T]he UAE risks depleting groundwater within 50 years at current consumption rates. [The water deficit in the United Arab Emirates (UAE) is projected at 0.84bn m³ by 2030…[T]he country spends almost $3.2bn per year on the production of desalinated water, accounting for about 14% of the world’s total output]…

"Although rich with oil and gas resources, the GCC states are the poorest in water, relying heavily on desalination projects, which supply 70% of their water needs and drain their budgets…Saudi Arabia’s water consumption is forecast to reach 7.32 bn m³ in 2030. The kingdom, which considered transporting icebergs from the South Pole in 1977, has pumped nearly 26% of the world’s total water desalination production over the past few years. In the next 17 years, the Saudi government plans to build 16 water desalination facilities worth $14bn, with a combined capacity of 2.1mn m³/d."

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"A MED-CSD project recently carried out studies of combined CSP and desalination plants in the south and eastern Mediterranean region, in which it assessed the water demand and deficit as well as of electricity demand…[It] found that all CSP technologies can be combined with thermal desalination systems…[P]arabolic dish systems and central receivers were excluded. ..[and] two options of combining CSP with seawater desalination were investigated: reverse osmosis [RO] power by electricity from a CSP plant and MED using heat and power from a CSP plant…CSP plants were found to save more fossil fuel and replace more conventional power capacity compared to other renewable energy sources like PV and wind power, especially if applied for desalination services…

"…[T]he more profitable [hybrid CSP water desalination] technologies were found to be Linear Fresnel mirrors for the solar field technology, and reverse osmosis for the desalination technology…Of the 72 different studied configurations, only considering the CAPEX for desalination, RO desalination was found to have a lower initial investment cost than MED. However, this cost excluded the maintenance cost over the years, especially the replacement cost for the RO modules every 5 years…The MED-CSD study stressed that a direct comparison for the desalination unit alone is misleading as the MED unit replaces the heat rejection section of the power plant (cooling tower) as well as expensive condensing stages of the steam turbine…MED is also gaining increasing market shares due to lower power consumption for pumps and for requiring less heat exchange surface…"

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"Currently, the use of desalinated seawater in the MENA countries relies mostly on fossil fuels, which are neither sustainable nor economically feasible - especially considering that oil and gas prices have increased by 300% since 2000…The region also relies on the over-exploitation of groundwater resources, which results in falling groundwater levels, intrusion of salt water into the groundwater reservoirs and desertification…

"Egypt…installed a solar sea water desalination system based on a thermal evaporation method…Libya…conducts research programs in both PV and solar thermal technology…[T]he King Abdulaziz City for Science and Technology (KACST) launched the National Initiative for Solar Water Desalination (NISWD)…[T]he desalination process will hinge on a nanomembrane that filters out salts as well as potentially harmful toxins in water while using less energy than other forms of water purification…Abu Dhabi launched a pilot project for the world’s largest underground reservoir…[and is] testing a new system to desalinate sea water using solar energy…"