When selecting the solar panel for a solar street light, the following key factors should be taken into consideration:
Types of solar panels: Solar panels are divided into monocrystalline and polycrystalline varieties. Monocrystalline silicon solar panels have a higher efficiency and lower light degradation, but are more expensive; polycrystalline silicon solar panels have a lower efficiency but are cheaper.
Open-circuit voltage and operating voltage: The open-circuit voltage and operating voltage of the solar panel must be compatible with the street light controller. If a PWM solar street light controller is used, the charging voltage is 12V, the open-circuit voltage of the solar panel is generally around 20V, and the operating voltage is generally around 17.5V. If the charging voltage is 24V, the open-circuit voltage and operating voltage of the solar panel are twice that of the 12V. If an MPPT solar controller is used, the open-circuit voltage of the solar panel must not exceed the maximum input voltage of the controller. 。
Dimensions: There are many sizes of solar panels available, and you must decide what size is appropriate for your light pole installation based on your environment. Generally speaking, a smaller size is more suitable in terms of power consumption when the same power is available.
Generation capacity: The generation capacity of solar panels is closely related to factors such as light intensity, ambient temperature, and installation angle. Any change in any of these factors will affect its generation efficiency.
Material and photovoltaic conversion efficiency: Monocrystalline silicon has a higher conversion efficiency, reaching 17%-23%, while polycrystalline silicon typically ranges from 14%-19%. Lithium-based batteries with high output voltage and large capacity are generally preferred for battery storage.
Installation Area: Choose the solar panels based on the climate conditions of the actual installation area. Monocrystalline silicon is suitable for use in areas with frequent overcast skies and relatively insufficient sunlight; polycrystalline silicon is suitable for use in areas with abundant sunlight.
Required output power: The output power of the solar panel also affects its size. The unit area output power of the solar panel is about 127 WP/square meter, and the larger the area, the greater the output power. Generally, the output power of the solar panel should be 3-5 times or more than the light source power.
Price and Budget: Compared to polycrystalline silicon solar cells, monocrystalline silicon solar cells have higher energy conversion efficiency and better photovoltaic conversion performance, but they are also more expensive. If the budget allows, it is recommended to choose monocrystalline silicon solar cells to improve the solar street lamp's power generation efficiency and lighting effect.
Taking all these factors into consideration, the appropriate solar panel can be chosen based on specific application scenarios, budget, and local climate conditions.
