1. Photoelectric conversion efficiency of solar panels
• Definition: The efficiency with which a solar panel converts sunlight into electricity.
• Common value: The photoelectric conversion efficiency of solar panels commonly available on the market is between 15% and 22%. The conversion efficiency of high-efficiency monocrystalline silicon solar panels can reach more than 22%, while the conversion efficiency of polycrystalline silicon solar panels is usually between 16% and 18%.

2. Inverter conversion efficiency
• Definition: The efficiency with which an inverter converts direct current (DC) to alternating current (AC).
• Common values: A high-quality inverter conversion efficiency is usually between 95% and 98%.

3. Charge and discharge efficiency of the energy storage system
• Definition: Energy loss of an energy storage system during charging and discharging.
• Common values: The charge and discharge efficiency of lithium-ion batteries is usually between 90% and 95%.

4. Overall system efficiency
• Definition: The total efficiency of the entire process from the absorption of sunlight by a solar panel to the use of electrical energy by the end user.
• Calculation method: Overall system efficiency = photoelectric conversion efficiency × inverter conversion efficiency × energy storage system charging and discharging efficiency
Consider a typical system configuration as follows:
• Photovoltaic conversion efficiency of solar panels: 18%
Inverter conversion efficiency: 96%
• Charge and discharge efficiency of energy storage system: 92%
The overall efficiency of the system is: [\text{overall efficiency of the system} = 18% \times 96% \times 92% = 15.7%]

Influencing factor
• Weather conditions: Cloudy or rainy days can reduce the efficiency of solar panels.
• Installation Angle and orientation: The optimal installation Angle and orientation of the solar panel maximizes light reception.
• Cleanliness: Dirt and obstructions on the surface of the panel can reduce the photoelectric conversion efficiency.
• Temperature: High temperatures can reduce the efficiency of solar panels.