| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot water storage type water heater capable of performing boiling of water in a hot water storage tank by electric energy by avoiding a power generation time zone of a photovoltaic power generation device, by predicting the power generation time zone of the photovoltaic power generation, with a simple constitution.SOLUTION: An initial limit time zone setting unit 122 sets an initial limit time zone TWR according to an input operation of a user. A time difference calculation unit 123 calculates a start time difference ΔST which is a difference between sunrise time of the day when the initial limit time zone TWR is set and start time of the initial limit time zone, and a finish time difference ΔET which is a difference between sunset time of the day when the initial limit time zone is set and the finish time of the initial limit time zone. A present day limit time zone setting unit 124 sets a boiling limit time zone WG2 on the execution day of the boiling operation by making the time in which the sunrise time is shifted by the start time difference ΔST as the start time RST, and by making the time in which the sunset time is shifted by the finish time difference ΔET as the finish time RET.SELECTED DRAWING: Figure 6 |
