Comprehensive Evaluation of Photovoltaic Solar Plants vs. Natural Ecosystems in Green Conflict Situations

This study aims to develop a comprehensive method for evaluating the environmental cost/benefits of photovoltaic (PV) solar plant installation versus conserving natural ecosystems. First, the positive and negative impacts of installing PV solar plants in regions with natural ecosystems are reviewed. For focus and quantification, climate change mitigation and economic benefit were considered as benefits, and the loss of carbon sinks and biodiversity as well as disaster risk were considered as negatives. These items were also integrated as external costs using a life-cycle assessment method, and a ratio of positive versus negative impacts (P/N ratio) was developed, as part of our evaluation. The method was applied to a case study in Hyogo Prefecture, Japan, where 361 large PV solar plants have been installed in areas that previously supported natural ecosystems. Prior to the PV installation, 25.5% of the plants were cleared from the natural ecosystem. Consequently, the annualized benefits (costs) for these Hyogo plants were estimated to be 101.16 (73.88) million USD, which yielded a P/N ratio of 1.37, indicating that their benefits outweighed their costs. An economic benefit was found to be one of the parameters that significantly influenced the P/N ratio.