Storyline: Innovative design enlarges storage capacity of world's first dual-tower solar thermal plant [Voice_over] In the vast Gobi Desert in northwest China's Gansu Province, a shimmering solar project has just started trial operations. Billed as the world's first dual-tower single unit concentrated solar power, or CSP, plant, the facility uses 27,000 heliostats to track the sun like a field of high-tech sunflowers. They're made of ultra-clear glass with 94-percent reflectivity and need to be cleaned often. The energy they capture is stored in two massive tanks containing molten salt with a storage capacity of 600,000 kWh of electricity. Compared with traditional single-tower CSP plants, the dual-tower allows for greater energy capacity, and storage capabilities. The solar thermal power plant is a central part of a larger clean energy project in the region that's expected to generate 1.8 billion kilowatt-hours of clean energy annually. [Restrictions : No access Chinese mainland]