On October 14, the world's first ultra-high altitude photovoltaic demonstration base, the State Power Investment Corporation's Xingchuan Demonstration photovoltaic Power Station in Garze Prefecture, Sichuan Province, was put into operation.
The project is located in Dinggong Prairie, Zhengdou Township, Xiangcheng County, Garze Prefecture, Sichuan Province, with a total installed capacity of 600,000 kW and an annual average power generation of 1.268 billion KWH after the full capacity is connected to the grid, making it the largest single photovoltaic power generation project in Sichuan Province.
'Different from a pure photovoltaic power station, the photovoltaic demonstration base is like an 'encyclopedia' of the photovoltaic industry.' Zhou Qingjia, chairman of State Power Investment Sichuan, said the further value of the demonstration base is to explore the development of photovoltaic technology and improve the efficiency and cost performance of photovoltaic power generation.
Photovoltaic power generation equipment is composed of components, supports, inverters, etc., with dozens of forms and sizes, forming hundreds of technology combinations. Conventional power stations generally choose one or two technology combinations, but Xingchuan demonstration photovoltaic power station has built five demonstration comparison areas, including photovoltaic modules, inverters, supports, energy storage and comprehensive comparison, and designed about 130 kinds of demonstration test schemes. It will comprehensively carry out demonstration on the innovative application of photovoltaic equipment, photovoltaic technology routes, energy storage equipment, big data, Internet of things and other new equipment and technologies. It basically covers the mainstream products of photovoltaic and energy storage industries and innovative products with promotion and application.
At present, mountain PV has become the focus of innovation and attention in the industry, but the ultra-high altitude and mountain climate have an impact on the operating efficiency of equipment, equipment insulation performance and thermal insulation performance of energy storage equipment. The project adopts the '1+N' development model combining the integration of network, source, charge and storage, multi-energy complementarity and rural revitalization of Tibetan areas. It has three functions, namely, the demonstration of ultra-high altitude photovoltaic technology, the demonstration of 'photovoltaic + ecological restoration' and the demonstration of smart photovoltaic power station, filling the gap of China's photovoltaic demonstration base in ultra-high altitude and mid-latitude areas. This paper provides reference for the photovoltaic construction in the Sichuan-Tibet Plateau region and the similar scenes in the whole country.
The average altitude of the demonstration photovoltaic power station in Xingchuan is 4,000 meters. The construction of the project is faced with many difficulties, such as high altitude, harsh environment, great construction intensity and difficulty, and difficulties in the organization of materials and equipment.
In the face of the established construction period target, in order to complete the construction tasks on time, efficiently and with high quality, the State Power Investment Sichuan Company formed the 'Plateau Red Star' Party member commandos, which set off a boom in the project construction line. In half a year, they completed the 63-kilometer 220-kilovolt transmission line across the mountains, and completed the installation, commissioning and testing of the project's boost station equipment in only one month. At the same time, they actively and effectively dealt with the COVID-19 epidemic prevention and control and the impact of the September 5 Luding earthquake in Ganzi. At this time, it will be exactly 10 months before the launch of the demonstration base on December 14, 2021, which is two months ahead of the expected production date.
Tang Yan, assistant to the general manager of State Power Investment Sichuan Co., LTD., and person in charge of the project owner unit, introduced that the construction difficulties of ultra-high altitude mountain photovoltaic power station mainly come from its environmental factors: 'In terms of transportation, the road conditions for the approach to the project are complicated, and the material handling is difficult; Oxygen is thin, the temperature difference between day and night is large, personnel efficiency, mechanical efficiency are reduced.'
In terms of equipment, the air pressure is small, the same voltage, the air is easy to produce ionization phenomenon, there are also high requirements for equipment selection, especially in the selection of inverter must meet the requirements of high altitude area electrical technology. In addition, the low temperature environment in the high altitude area requires high thermal insulation performance of the energy storage system, especially the electrochemical energy storage battery.
In terms of environmental requirements, the project is located in the western Sichuan Plateau pastoral area, which is an important ecological barrier in the west of China. State Power Investment takes environmental protection as a necessary prerequisite in the construction process. During the construction period, it should protect the native vegetation in the project area and minimize the damage to vegetation. Vehicles, equipment and personnel will not destroy the original soil layer and surface plants after entering the project, and vegetation restoration will be carried out immediately after the construction. Through supporting water storage and irrigation systems, the project also adopts classified management measures for different degrees of degraded grassland, tailor-made photovoltaic ecosystem integrating 'power generation, water collection, water storage, irrigation and planting', and created a demonstration sample of 'photovoltaic + ecological governance'.
Author: Li Xin
Editor: Jiang Pengxin
Proofread: Xu Yan