The characteristics of a 20W polycrystalline solar panel can vary slightly based on the specific manufacturer and the design of the panel. However, some general characteristics of a typical 20W polycrystalline solar panel might include:

1. Power Output: The power output of the panel is approximately 20 watts. This rating indicates the maximum power that the panel can produce under standard test conditions, which include a specific temperature, solar irradiance, and other factors.
2. Efficiency: Polycrystalline solar panels typically have a slightly lower efficiency compared to monocrystalline panels. A 20W polycrystalline solar panel might have an efficiency ranging from 13% to 16%, meaning it can convert 13% to 16% of the sunlight that strikes it into electricity.
3. Dimensions: The dimensions of a 20W polycrystalline solar panel can vary, but a typical panel might measure around 13 to 15 inches in width and 20 to 25 inches in height, with a thickness of about 1 to 1.5 inches. These dimensions can vary depending on the specific model and manufacturer.
4. Material: Polycrystalline solar panels are made from multiple silicon crystals. The manufacturing process for polycrystalline panels is simpler and more cost-effective, but it can result in a slightly lower efficiency compared to monocrystalline panels.
5. Durability: Polycrystalline solar panels are designed to be durable and long-lasting. They can withstand various weather conditions, making them suitable for use in different climates.
6. Warranty: Similar to monocrystalline panels, most polycrystalline solar panels come with a warranty that covers their performance over a specific period. A typical warranty for a 20W polycrystalline solar panel might include a product warranty of 5 to 10 years and a performance warranty of 25 years, guaranteeing a certain level of power output over the panel’s lifetime.
7. Application: 20W polycrystalline solar panels are commonly used in small-scale applications, such as powering small electronic devices, charging batteries, or as part of small off-grid solar systems for applications like outdoor lighting, small pumps, or ventilation systems.

It’s important to note that specific specifications and characteristics might differ depending on the manufacturer and the specific product line. For precise technical details and performance characteristics of a particular 20W polycrystalline solar panel, it is advisable to refer to the datasheet provided by the manufacturer.