For low-power portable electronics, like calculators or small fans, a photovoltaic array may be a reasonable energy source rather than a battery. Although using photovoltaics lowers the cost (over time) of the device to the user-who will never need to buy batteries-the cost of manufacturing devices with photovoltaic arrays is generally higher than the cost of manufacturing devices to which batteries must be added. Therefore, the initial cost of photovoltaic devices is often higher than battery-operated devices.
In other situations, such as solar battery chargers, watches, and flashlights, the photovoltaic array is used to generate electricity that is then stored in batteries for use later.
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