Future Scenarios and Assessment of Gradual Diffusion of Renewable Energy Technologies towards 2050: Case Study of a Japanese Municipality

Abstract

In order to design pathways toward carbon neutrality, it is indispensable to evaluate the effects of introducing promising renewable energy, which plays an important role in reducing greenhouse gases. In this study, we developed a methodology for multidimensionally assessing the effects and impacts of gradual diffusion of three promising renewable energy technologies for the consumer market—Photovoltaics (PVs), electric vehicles(EVs), and Vehicle to Home (V2H)—in terms of five indicators, comprising CO2 emission reduction, cost saving, self-consumption, energy sufficiency, and self-sufficiency, using System Advisor Model (SAM). In the assessment, we assumed that the penetration of these technologies and products gradually increases up to 2050 while taking into account their life cycles. For assessment, we conducted a case study in Suita City, Osaka Prefecture (Japan), as an example of an urban area where their diffusion is likely to have a substantial impact. The results of our analysis showed that a 60% reduction in CO2 emissions can be expected by 2050 in the accelerated deployment scenario. In the same scenario, cost savings of more than 25% can be expected by 2050, although some initial investment is required, indicating significant long-term benefits. We found that from around 2035 onward, the deployment of three technologies, PVs, EVs, and V2H, yields greater benefits than the adoption of PVs alone, demonstrating the importance of evaluating the impact of gradual technology diffusion over a long timeframe. We argue that the method to evaluate the effects of gradual diffusion of technologies could be of use for design policy measures towards carbon neutrality by 2050.

Keywords: renewable energy technologies, future scenarios, gradual diffusion of technology, Techno-economic analysis, multidimensional assessment