Fig. 3: Relationship between hourly electricity spot market price and hourly electricity demand in Chubu, Chugoku, Hokuriku, Kansai, Hokkaido, Kyushu, Shikoku, Tohoku, and Tokyo.
From: The impacts of carbon pricing on the electricity market in Japan

The scatterplot and smooth line capture the non-linear relationships between electricity price and demand in nine regions.