Saudi Arabia, the world's leading oil producer, has completed its biggest solar power plant as the Persian Gulf petro-powers increasingly turn to solar energy and other renewables.

Riyadh wants to generate one-third of the kingdom's electricity needs by 2032 to save 523,000 barrels of oil per day, currently used to fuel power stations, for export, particularly with oil prices at more than $100 a barrel.

The Saudis aim to have 41,000 megawatts of solar capacity in the next two decades, says Maher al-Odan of the King Abdallah City for Atomic and Renewable Energy.

The newly inaugurated 3.5MW photovoltaic plant may be the kingdom's biggest but it's small fry in terms of global solar projects, even compared to the world's largest single-unit solar power plant, a 100MW project known as Shams-1.

That's nearing completion in oil-rich Abu Dhabi in the United Arab Emirates, Saudi Arabia's eastern neighbor.

But the kingdom plans to spend at least $109 billion over the next 20 years on a solar power network as it moves toward a post-oil future.

The Arab monarchies of the Persian Gulf, which sit on around one-fifth of the planet's oil reserves, are embarking on a green revolution that will transform their economies by freeing oil for export rather than for domestic consumption to fuel power stations.

This is taking place as an ambitious $560 billion project to supply Europe with vast amounts of solar thermal energy from North Africa seems to be running out of steam as industrial backers get cold feet and a key pilot project in Morocco is stuck in the Saharan sand.

The Saudis' new solar plant "represents an important milestone in the development of the solar industry in the Kingdom of Saudi Arabia," said Ron Shen, vice president of China's Suntech Power Holdings that provided the 12,694 ground-mounted photovoltaic panels for the project.

The move toward solar power "follows years of growth in Saudi Arabia and others in the gulf that mean countries are now burning so much of their own oil and gas resources that they could become net fuel importers within 20 years unless they find new sources of energy," the Financial Times observed.

Eventually, solar energy advocates see the Gulf Cooperation Council states -- Saudi Arabia, the United Arab Emirates, Kuwait, Qatar, Oman and Bahrain -- providing electricity to Egypt and the region, and even Europe, eager to cut its dependence on Russian gas supplies.

The leading solar effort in the gulf is the Shams 1 project in Abu Dhabi, the economic powerhouse of the Emirates which sits on 8 percent of the world's proven oil reserves.

Shams 1 will have an electricity generation capacity of 100 megawatts when it's completed in the next few months.

"This could be the world's next renewable energy center," Mark Robson of the Oliver Wyman energy consultancy in Dubai, the Emirates' financial hub, observed during a recent U.N. global climate change conference in Qatar, the leading exporter of liquefied natural gas.

Built by solar power giant Masdar, the project is designed to provide 20,000 homes with electricity. Follow-on projects Shams 2 and 3 are expected to produce similar amounts of electricity.

"Once completed, Shams 1 will be one of the largest concentrated solar power plants in the world," and the largest of its kind in the Middle East, declared Yousef Al Ali, general manager of the Shams Power Co.

Eventually the solar project, initiated in 2006, will become low-carbon Madinat Masdar, Arabic for Source City, built by the Abu Dhabi Future Energy Co., a subsidiary of the state-owned Mudabala Development Co.

Fahd bin Mohammed Al-Attiya, director of Qatar's national food security program which is helping develop the country's solar power, says the tiny emirate is working to run some 1,800MW of solar energy into its power grid by 2018.

That's 16-18 percent of the emirate's electricity needs.

Attiyah said he saw the GCC "following in the footsteps of Desertec," the pioneering Moroccan project launched three years ago with plans for massive solar-energy farms across North Africa supplying power for the Middle East and Europe.

But that ambitious German-led project, with an envisaged Mediterranean supergrid, has recently run into problems after Siemens and Bosch, two of the main industrial supporters, backed out and the German government lost interest.