The traditional method of sand control is to mobilize the masses to plant trees and grass, but this method has a large investment, low returns and long time. The establishment of a desert solar power station through large-scale mechanized operations is a new method for sand control. In recent years, PV system has spread everywhere inChina, and it has also been widely promoted and applied in the southern margin of the Tengger Desert.
1. Overview of the study area
Zhongwei Shapotou District is located in the central and western part of Ningxia Hui Autonomous Region, with a desert area of 3.67×104km2. Its distinctive feature is mainly mobile sand dunes, with a certain proportion of fixed and semi-fixed dunes. The annual sunshine time of the study area is 3000-3200h, and the total annual radiation is 140-160kJ/(cm2a-1), which provides a good natural condition for the development of solar photovoltaic industry.
2. Data source
The data of this study mainly comes from the landsat images of the period provided by the USGS website in the past 3 years, and the actual GPS data and field visit interview records were recorded in the field from July to August 2014. Using the arcgis platform, combined with field actual investigation, the distribution of solar photovoltaic panels in four periods was obtained. The changes and trends of the distribution of solar photovoltaic panels in the adjacent two-stage images were analyzed.
3. Results analysis
Temporal and spatial dynamic changes of solar photovoltaic panels
The geographical distribution of solar photovoltaic panels can reflect the characteristics of human activities and their impact on the desert. Through the information extraction, the classification results of remote sensing images of each phase of the study area are obtained.
Before September 2011, solar photovoltaic panels were erected along the road, reaching the goal of protecting solar photovoltaic panels to some extent. From September 2011 to June 2013, the erection of solar photovoltaic panels in the region deviated from the highway, and gradually changed from highway protection photovoltaic panels to photovoltaic panels for sand control. In June 2014, the industrialization and scale were initially realized, and the function of preventing wind and sand was basically realized. In summary, in the past three years, the erecting area of solar photovoltaic panels has been reduced from small to large, and the space has been shifted from south to north, achieving a close degree from fragmentation to concentration, functionally protecting roads from photovoltaic panels to utilizing photovoltaics. The board realizes the transformation of wind and sand control.
Solar photovoltaic panel morphology change
The new erection method realizes photovoltaic building integration, i.e. BIPV (Building Integrated PV, PV ie Photovolta-ic). Photovoltaic Building Integration (BIPV) technology is a technology that integrates solar power (photovoltaic) products into buildings. The solar greenhouse is built under the photovoltaic panel, and the resource can be more effectively utilized in a limited space. While saving space, the lower greenhouse can be used for vegetable planting, etc., and the land utilization per unit area is improved.
The new way of integrating photovoltaic buildings makes fuller use of land resources and can achieve greater benefits through the solar greenhouse. The new PV building integration model will be more utilized and promoted.