Energy Yield
Solar energy yield is the total amount of electricity generated by a solar PV system over a defined period, typically one year. It's the fundamental output metric that determines a project's energy value and economic return.
Energy yield is most often expressed as:
- kWh/year: Total annual production (e.g., "this 10 kW system produces 18,000 kWh/year")
- kWh/kWp/year (Specific Yield): Production per kilowatt of installed capacity, allowing comparison across different system sizes
Specific yield is particularly useful for comparing the solar resource quality at different locations:
- 1,800 kWh/kWp/year → excellent resource (Southwest US)
- 1,400 kWh/kWp/year → good resource (Southeast, Mountain West)
- 1,100 kWh/kWp/year → moderate resource (Northeast, Pacific Northwest)
Factors Affecting Energy Yield
- Solar irradiance: The most important factor — more sun equals more production
- System size (kWp): Directly proportional to yield
- Performance ratio: System losses reduce yield from theoretical maximum
- Temperature: Hot climates reduce panel efficiency, partially offsetting high irradiance
- Degradation: Annual yield decreases by ~0.5%/year as panels age
- Shading: Nearby obstructions reduce yield significantly
Calculating Energy Yield in SolarScope
SolarScope estimates energy yield based on:
- NASA POWER irradiance data for your location
- Your system size and configuration
- Default or custom performance ratio
The analysis provides both monthly and annual yield estimates in the project dashboard. Year-over-year yield with degradation can be modeled using the AI assistant.