The CGN Delingha 50MW Solar Thermal Demonstration Project, the first large commercial solar thermal demo power station in the country, came into service on Oct 10, making China the eighth country in the world to seize such technology.
It was also China’s first power station that received a preferential loan from the Asian Development Bank.
The project, located in the Gobi desert at Delingha, Qinghai province, covers an area of 2.46 square kilometers, which is equivalent to more than 360 standard football fields. It adopts parabolic-trough concentrated solar power (CSP) technology, supplemented by nine-hour molten salt heat storage.
It consists of four parts including a solar island, a heat transfer and steam generation system, a heat storage island, and an electricity generation island.
The heat collector on the solar island is comprised of 250,000 retroreflectors totaling 620,000 square meters, evacuated tube collectors of 110,000 meters, tracking and actuating devices. They act like sunflowers, tracking the sun's rotation and collecting the heat.
The molten salt storage tank on heat storage island, with a diameter of 42 meters, is the largest of its kind in Asia. The whole set of low-cost, non-polluting, large energy storage systems enables stable and continuous power generation for 24 hours even with insufficient sunlight, which will significantly improve the stability of the regional power grid.
The Delingha project saw the construction of its major structure commence in Aug 2015, and the units connected to the grid on June 30. The team has been exploring different operation modes, optimizing control strategy and increasing operation efficiency from July to September to make all system parameters reach the ideal value before the plant was put into use, said Wang Zhigang, president of CGN New Energy Delingha Co.
The plant can generate nearly 200 million kWh of electricity annually, slashing standard coal use by 60,000 tons, reducing emissions of carbon dioxide by 100,000 tons, which is equivalent to the effect of planting trees across an area of 4,200 mu (280 hectares).
According to Wang, the project lies on the Qinghai-Tibet Plateau, 3,000 meters above sea level. In addition to technical difficulties, it is faced with terrible natural conditions, including bitter cold in winter, mosquitoes in summer, and an oxygen content 30 percent lower than plain areas.
Compared with photovoltaic power, solar thermal energy features the continuous and steady generation of electricity, enjoying greater development potential. China had a late start in this sector and it remains a new industry.
With no experience to draw from, the Delingha team mapped out the course of the solar thermal project in a high-altitude cold area, pioneering the practice of injecting oil into a low-temperature environment in winter.
The operation of the project signifies that CGN can seize on its core capabilities to integrate a large solar thermal power station system, establish China’s solar thermal industrial chain, set up industrial technology and create a standardization system. CGN received approval to build a national research center for solar and thermal energy thanks to the project.
According to CGN spokesman Yuan Changhong, the project helps the country accumulate construction, operation, maintenance and management experience in the solar thermal industry, and lay a solid foundation for building large solar thermal power stations more safely and economically.
Prior to the Delingha project, CGN had 10 years experiences in developing solar energy. It won the contract for the 10MW grid-connected PV plant in Dunhuang, Gansu province, also known as China’s first PV concession bidding demo project; and the 300MW PV plant in the coal-mining subsidence areas of Datong in Shanxi province.
To date, CGN New Energy Holdings’ solar power projects have been spread across 29 domestic provinces and regions. It ranks third in the country with an installed capacity of more than 2.58 GW.
China Solar Thermal Power Generation Standardization Technical Committee approved the Solar Thermal Power Generation Technology Standard System compiled by the company on Sept 18, said Li Yilun, president of CGN New Energy Holdings.
At the 2018 China International CSP Station Conference, the Delingha project was recognized by the CSPPLAZA Awards for its contribution to boosting China’s solar and thermal industrial growth.
In addition to solar power, CGN also leads the wind power industry with projects such as the 100MW Shanghai Donghai Bridge Offshore Wind Farm, China’s first large offshore wind power project; the 150MW Rudong Offshore Wind Farm, the first of its kind in the country that lives up to the national “double ten” standard; the 300MW offshore wind power project in Pingtan, Fujian province, the most difficult of its kind in the country; the 400MW Nanpeng Island Offshore Wind Farm in Yangjiang, China’s largest single offshore wind power project; and the 24MW floating wind power project in the sea off the island of Groix, France and even Europe’s first offshore floating wind power demo project.