Comparative impacts of fixed vs. flexible photovoltaic supports on near-surface features in karst landforms

Fixed supports (rigid structures) and flexible supports (tensioned cable systems) are two main methods used in constructing photovoltaic power plants, and their construction technology has significant differences. This comparative study assessed their environmental impacts on near-surface characteristics during constructing photovoltaic power plants in karst mountainous regions. Our findings revealed significant but different surface disturbances between these installation approaches. While both systems caused terrain modifications through foundation works and access road construction, the fixed support completely disturbed 100% of the construction area compared to < 30% disturbance from flexible supports. Compared with the original ground, fixed support caused approximately 22% increase in bedrock exposure rate, while decreased 5% for the flexible support. Additionally, only 17% of the original vegetation coverage remained for the fixed support after construction, compared to 53% for the flexible support. The lower bedrock exposure rate and higher vegetation coverage of flexible support indicated that it had less surface disturbance area than fixed support. These results suggested that in ecologically sensitive karst terrains characterized by severe rocky desertification, challenging revegetation conditions, and low land productivity, flexible support photovoltaic technology represented a significantly less disruptive technology for minimizing surface disturbance and preserving fragile mountain ecosystems.