Any solar panel’s efficiency is affected by the below-mentioned factors:

The efficiency of the photovoltaic (PV) cells: which is determined by the cell design and silicon type
The overall efficiency of the panel: which is determined by its panel layout, size, and configuration.
Sunlight intensity: When the sun is at its strongest in the afternoon, a solar panel’s output may increase since that is when it can collect the most solar energy.
Installation: For solar panels to capture the most sunlight, the installation must be done properly. A panel’s angle and how much light it receives are two key components of maximizing efficiency.
Shading: Shadows will reduce the current through the solar panel if even a small portion of it is shaded. The amount and type of shading may impact the efficiency of energy delivery and lead to lower outputs and power losses.
Building of heat: Warm climate regions usually risk heat buildup in solar panels since they cannot function efficiently at higher temperatures.
Maintenance: Solar panels usually have long warranties of 15-25 years. However, they need to be cleaned and maintained regularly in order to maximize their efficiency.

By considering the above factors, one can find the key to how to increase solar panel efficiency.