Effects of renewable energy expansion on fossil-fuel consumption: A case study in Miyakojima, Japan

2019 Fiscal Year Final Research Report

• Project/Area Number: 15K00644
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Design and evaluation of sustainable and environmental conscious system
• Research Institution: Doshisha University
• Principal Investigator: Ishida Hazuki 同志社大学, 経済学部, 教授 (20302309)
• Project Period (FY): 2015-04-01 – 2020-03-31
• Keywords: 再生可能エネルギー / 化石燃料

Outline of Final Research Achievements

The present study assessed the extent to which increasing the share of variable renewable energy (VRE) in Miyakojima decreased fuel consumption in thermal-power generation. The detailed time-series data on the load factor and fuel consumption of thermal-power plants often remain undisclosed, and Miyakojima is no exception. Consequently, this study was conducted based on published energy-related data and an interview survey conducted in Miyakojima. It was found that increasing the share of VRE did not lower the thermal efficiency of thermal-power generation. However, further expansion of VRE share could degrade the thermal efficiency.

Free Research Field

エネルギー経済

Academic Significance and Societal Importance of the Research Achievements

本研究の社会的意義は，低炭素社会の担い手としてとりわけ期待されている再生可能エネルギー（なかでも風力・太陽光発電）が，本当に期待通りの効果をあげているのかを追求したことにある。風力・太陽光発電が増えれば火力発電の負荷率が低下し，熱機関の特性から，火力発電の熱効率の低下が懸念される。その程度が大きければ，火力発電量の低減による化石燃料消費の削減効果が相当に失われてしまうことになる。こうした視点からの実証分析は，宮古島市に限らず，国内外において極めて少ないのが現状である。