Project showcases 'green electricity' path of 'black gold'

As the country is fostering a sound environment for the development of green and low-carbon industries, a key photovoltaic project has been put into operation in North China's Inner Mongolia autonomous region.

The 14.9988 megawatt distributed photovoltaic power station under Buliangou Coal Mine, located in Ordos, is a shining example of a transformation from "black gold" to "green electricity". A photovoltaic system with an installed capacity of 1 MW theoretically means it can generate 1 million watts of electricity per second — enough to meet the daily electricity needs of a large number of households and industrial facilities.

The Government Work Report, delivered at the annual national legislative session in Beijing in March, called for fostering a sound environment for the development of green and low-carbon industries, and the construction of new energy bases in desert areas, the Gobi and other arid areas, to help boost the nation's dual-carbon goals — achieving carbon peak before 2030 and carbon neutrality before 2060.

The project, partially built by China Railway No 4 Engineering Group, is the largest installed capacity photovoltaic project in the whole group of Huadian Coal Industry — a branch of China Huadian Corp established on Dec 29, 2002.

Installing 25,636 panels of 585-Wpeak high-efficiency monocrystalline silicon double-sided double-glass photovoltaic modules, the project can generate an annual average of 23.1 million kilowatt-hours of power as it is combined with intelligent string inverters, able to meet some of the electricity needs in the mining area.

"Compared to traditional energy sources, this project can help save approximately 7,040 metric tons of standard coal each year, slash carbon dioxide emissions by over 18,300 tons and let the coal mine save more than 20 million yuan ($2.8 million) in electricity expenses each year," said Zhai Tengfei, technical leader the CREC4 department for building the project.

Covering an area of 18.7 hectares, it has made use of the land in the waste dump area of the colliery's railway loop in Juungar Banner, and innovatively adopts a mode of pointed storage shed roof installation.

"By installing photovoltaic modules in the north-south direction, the absorption time of sunlight is maximized, and the number of photovoltaic panels installed has doubled the number on the similar land area, creating a new model of 'photovoltaic + coal mine' industrial integration," said Zhai, who is from CREC4 Electrical Engineering Co Ltd.

The construction has met with a series of harsh challenges, such as large temperature differences between day and night, as well as frequent sandstorms in the local area.

"By maximizing our technology, the back of the double-sided power generation components can absorb reflected light from the sand, which can not only help increase power generation efficiency and solidify the robustness of the power generation components themselves, but also better ensure the stable operation of the photovoltaic system under harsh weather conditions," said Jia Yating, manager of the CREC4 department for building the project.

In response to the special requirements of the pointed-installation scheme, the CREC4 construction workers also innovated the component disassembly and installation process in a bid to achieve fast work, which is convenient for later operations and maintenance.

"The power station is equipped with an advanced photovoltaic power-generation monitoring system, which can monitor the real-time power generation status of each group of photovoltaic panels, accurately optimize power generation efficiency, and raise the fault diagnosis and maintenance efficiency," noted Jia.

"Moreover, it will also introduce a photovoltaic robot cleaning system, so as to further enhance the intelligent operation and maintenance level of the power station," added Jia.

The project is expected to be officially connected to the grid for power generation at the end of September, bringing significant economic and environmental benefits to Huadian Coal Industry Group. In addition, it has taken a pioneering path for the green and low-carbon development of traditional coal enterprises in Inner Mongolia.