著者

山田 武史 所 寿洋 中島 忠司 中村 勇人 山野 健治 長井 孝之 笹川 雄司 一色 正男

出版者

一般社団法人 エネルギー・資源学会

雑誌

エネルギー・資源学会論文誌 (ISSN:24330531)

巻号頁・発行日

vol.44, no.1, pp.39-46, 2023-01-10 (Released:2023-01-10)

参考文献数

10

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In order to expand the use of renewable energy, a shift from "selling" to "self-consuming" of surplus electric energy generated by photovoltaic power generation (PV) is necessary. As for the means of the self-consumption, water heater with a hot water tank, which can store energy at relatively low cost as hot water, is attracting attention. Hybrid water heater, that has both an electric heat pump and a gas heat source, stores hot water to a relatively small tank compared to a simple electric heat pump water heater at less electric energy. Since it also has a gas heat source, there is no need to worry about running out of hot water even with a small tank. By combining a hybrid water heater and a storage battery system, an improvement of self power consumption ratio of PV energy is expected compared to the stand-alone usage of a hybrid water heater. This article reports the improvement result in an actual house. The self-consumption of PV energy used at the hybrid water heater was improved by 11.6 % in winter, 23.8 % in mid seasons, and 4.9 % in summer. Then the CO2 emission is reduced by 33 % a year.