An Analysis of the Decline in JEPX Day-Ahead Prices: Some Impacts of RES Supply and the COVID-19-Induced Demand Downturn

Author Name IKEDA Shin Suke (Otaru University of Commerce)
Creation Date/NO. October 2020 20-J-040
Research Project Policy Issues on the Electricity Market Reform after 2020
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I analyze data of equilibrium day-ahead prices, trading volumes, sell and buy order volumes at the Japan Electric Power Exchange (JEPX) from 30-March-2015 to 9-July-2020. A time-series analysis suggests that (a) the sell bid, buy bid and transaction volumes have followed a strong co-cycling trend since the beginning of the implicit auction of the transmission line right, and (b) the trading volume is stably related to 83% of the buy order volume. Additionally, I estimate the price elasticities of demand and supply from surveillance reports and show that (c) individual quarter transition is parallel to the price-trading volume ratio. A cross-sectional analysis suggests (d) the first and second quarter's day-time sell order volume is increasing over years, and (e) stronger pattern on weekends and holidays. Finally, I explore the implications of the above in terms of the effect of photovoltaic power generation on recent price decline during the COVID-19 pandemic, and on the form and location of the market demand curve.