Status of desalination in Saudi Arabia

Write about the status of desalination in Saudi Arabia such as type, total capacity and number of plants.
-Estimate the size of photovoltaic plant (solar panel) required to supply the energy for water supply to Riyadh for municipal purposes. What would be the price of water per liter based on installation cost of solar panels.
-What do you think about the future of desalination plants in Saudi Arabia and which technology will dominate?