摘要 |
This invention relates to a method of controlling the light output of a solar-powered lighting device. The lighting device comprises a light source, a battery connected to the light source, a solar-power generator including a charger connected to the battery, and a control unit for performing the light output control. The method comprises:—charging the battery while solar-power is generated;—acquiring local day-light data;—repeatedly:—acquiring, at predetermined time intervals, local weather fore-cast data covering a predetermined time period, and determining a lighting output profile for the predetermined time period; and—driving the lighting device according to the lighting output profile, wherein said determining a lighting output profile comprises:—predicting a lighting demand for the predetermined time period on basis of first environment light data, which first environment light data comprises the local day-light data;—predicting a battery capacity for the predetermined time period on basis of a present energy storage level and second environment light data, which second environment light data comprises the weather forecast data and the local day-light data; and—determining the lighting output profile on basis of the lighting demand and the battery capacity under consideration of keeping the energy storage level above a predetermined minimum level during the predetermined time period.
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