Mecca city in the Hejaz, is going to become first green city of oil kingdom. Mecca features an extremely arid climate. Unlike other Saudi Arabian cities, Mecca retains its warm temperature in winter, which can range from 20 °C (68 °F) at midnight to 40 °C (104 °F) in the afternoon. Summer temperatures are considered extremely hot and break the 50 °C (122 °F) mark in the afternoon dropping to 30 °C (86 °F) in the evening. Rain usually falls in Mecca in small amounts between November and January.

Solar power is the conversion of sunlight into electricity, either directly using photovoltaic (PV), or indirectly using concentrated solar power (CSP).

Mecca proposes to build USD 640 million solar energy project. The city on January 5th, plans to select from a group of at least 20 bidders competing to build and operate facilities producing 385 gigawatt hours per year of power including 100 megawatts of solar capacity, said Mayor Osama al-Bar. “No city in Saudi Arabia owns power-generation assets, and we want to be first city that owns Power plans. The project will be established on an area of about 2m sqm. About 20 international consortiums consisting of about 100 companies will compete for the execution of the project.”
 
The Saudi Arabian government has said that it will invest $109 billion to establish a strong solar industry across the nation. The King Abdullah City for Atomic and Renewable Energy program is the jewel in this crown, and aims to develop 41 gigawatts of solar capacity over the next 20 years. 25 gigawatts will be installed in the form of solar thermal plants, and the remaining 16 gigawatts will be supplied by photovoltaic panels.
 
The heavily oil-dependent monarchy has a population of fewer than 30 million, yet covers an area about half the size of Europe and enjoys twice its sun exposure. The combination makes the solar power project both feasible and useful, despite its ambition.

Saudi Arabia is carrying out a significant industrial plan and, according to the most recent assessment by the United Nations Carbon Dioxide Information Analysis Center, ranks 10th in the world for its carbon dioxide emissions. Demography and development are causing an environmentally devastating rise in energy demand of 7% annually.

According to Saudi daily Al Eqtisadiah, the development is intended to meet growing energy requirements in the municipality and shave about SAR 2.2 billion off the holy city’s electricity bill.
 
A report published by Citi group last month said that Saudi Arabia, the world’s largest exporter of crude oil, could become a net importer of oil by 2030 if domestic energy consumption continues to grow at its current rate.  It said that depending on its success other municipalities in the Gulf’s most populous nation could develop their own solar energy strategy which could save the kingdom up to 8m barrels of oil per day by 2030.

Oil demand for use in domestic electricity consumption is currently rising by about 8% annually with a quarter of total output currently serving national energy requirements. All of Saudi Arabia’s natural gas, the kingdom's other natural resource is currently allocated for domestic consumption.

The city will need 385 gigawatt-hours of power each year and the whole project should be finished by 2018.