The cost of the solar power plant project is $ 200 billion. However, costs may increase because of the result of the difficult operation of the object. Saudi Arabia and SoftBank Group have signed an agreement on the construction of 200-billion-dollar solar power plants worth $ 200 billion. Saudi Arabia’s solar energy development projects are truly impressive, even under the rapid development of this trend. Obviously, the authorities of that country have made a strategic decision to transmit electricity to the Middle East through traditional hydrocarbon fuels and renewable sources instead of natural gas. The solar power plant area with a capacity of 200 GB is 1000-1500 km2. 

Source: Here.