Dynamics and regional heterogeneity in the generation efficiency of Japan's photovoltaic power plants focusing on new market entrants

The installation capacity of photovoltaic (PV) power generation systems in Japan in 2022 was 84 GW. Furthermore, 26.2 GW of PV power generation systems are expected to be newly installed by 2030, which indicates there will be several new entrants into the PV power generation market in the near future. We applied data envelopment analysis and the metafrontier global Malmquist index (MGMI) to Japan's PV power generation plant data (2016–2020) to investigate the static power generation efficiency and its growth considering new entrants and regional heterogeneity. The results demonstrated that the western region showed the highest static efficiency. Conversely, the eastern region experienced the largest increase in MGMI, with an average annual growth rate of 1.2 %. The decomposition analysis results of MGMI reveal that technological innovation within the same region is the primary driver of the growth in MGMI in all regions, while the catch-up effect has a negative effect. These results indicate that while advanced PV power plants in all regions contribute to advancing frontier technologies, others are insufficiently catching up. Policymakers should, therefore, encourage technology spillover between innovative power plants and others to promote the catch-up effect. We additionally identified innovative power plants that promote frontier technology, and the results demonstrated that plants that started operation before 2016 primarily contributed to technological innovation, indicating that the learning-by-doing effect of existing plants and the availability of favorable sites have a greater impact on power generation efficiency than introducing advanced facilities.