Chongqing Chengkou Mountain Solar Photovoltaic Case

Case of Mountain Solar PV in Chengkou County, Chongqing Municipality

I. Project Background and Site Selection

Chengkou County in Chongqing is located in the hinterland of the Daba Mountains, with an average altitude of over 2,000 meters and an annual sunshine duration of over 1,400 hours, which has the potential for high-quality photovoltaic development. As a typical demonstration project, CGNPC Xianyi PV Project Phase II (30MW) is located in Huanliu Village, Xianyi Town (coordinates: 108.40°E, 31.44°N), to realize energy transformation and enhance the synergistic development of rural revitalization through the development of mountainous solar photovoltaic.

Ⅱ.Second, the core of the technical program

1. Terrain optimization design

When constructing PV, it is necessary to conduct field investigation on the slope of the mountain, prioritize the south-facing slopes with slopes less than 25 degrees, and adopt tracked hydraulic piling machines to reduce the construction difficulty and enhance the stability of the stent.

The solar panels adopt square array layout, divide the area by 1:500 topographic map mapping, and adopt due south arrangement (inclination angle 25°-35°) to reduce shadow shading and improve the annual radiation receiving efficiency by 8%-12%.

2. Flexible support system

In terms of material selection for the stenting system, aluminum alloy + polymer composite flexible stenting can be used, reducing weight by 40%, adapting to the terrain undulation and strong wind environment, with wind speed greater than 15m/s.

Optimize the construction efficiency of solar equipment on site, modular installation to achieve single-day laying of 500 ㎡, shortening the duration by 30% compared with traditional rigid stenting.

3. Energy storage and grid-connected configuration

For the plan of energy storage capacity, lithium iron phosphate battery (3MWh) is rationed at 10% of the installed capacity to support the power supply of key loads of cold chain storage at night.

Grid connection standard for operation after installation, can be configured with bidirectional inverter and anti-reverse current device to meet the GB/T 19964-2022 standard, and the residual power feed-in subsidy of 0.35 yuan/kWh.

4.Program Composition

Mountain photovoltaic power generation, large-scale wind and solar complementary projects, complex geological conditions, high altitude, dynamic reactive power compensation device, computer and intelligent monitoring system.

III. Construction Challenges and Innovations

Difficulties	Solution	Technical Support
High altitude transportation	Manual backpacking + small-sized machinery transportation in sections to establish a temporary material transfer station.	Xianyi Project Construction Experience
Complex terrain	Flexible bracket layout across the ravine, reducing earth excavation by 50%.	Mountain PV Flexible Technology
Ecological protection	Avoid Chinese herbal medicine planting area and implement vegetation restoration project after construction.	EIA Special Requirements

The project adopts one-stop service and refined design, which greatly improves the land utilization rate and reduces the construction cost. It allows resources to be reused, improves the ecological environment and increases the income of local residents.

IV. Comprehensive Benefits

1. Economic benefits

The annual power generation is initially estimated to be 2.85 million kWh, with a self-consumption rate of 82%, which saves more than US$260,000/year in electricity costs.

2. Social Benefits

Due to the construction of photovoltaic facilities, it is necessary to build 20 kilometers of new roads to solve the problem of mass travel in three townships, and to promote local employment of 150 people.

At the same time, it reduces the use of diesel generators and lowers the cost of power supply in local mountainous areas by 40%.

3. Deserted Mountain Governance

Through the installation of solar photovoltaic equipment, and synchronize the treatment of barren mountain area of 698035m2, effectively improve the local soil erosion, and at the same time strengthen the mountain volcanic risk problems.

V. Implementation Suggestions

For the south-facing slopes with a slope of 10°-20°, avoiding the ecological red line and geologic disaster areas, it is a priority development area.
In the mountainous area, due to the factor of transportation, the UAV inspection + AI fault diagnosis system can be deployed, and the MTTR (Mean Time to Repair) is controlled within 2 hours to improve the O&M efficiency.