Dear William,
The Net Plant Power Output variable is the value calculated by the Linear Fresnel performance model. SAM applies additional performance adjustment factors based on the input values you specify on the
Performance Adjustment
page. For example, the default value of "Percent of annual output" is 96%, which would cause the Hourly Energy value to be 96% of the Net plant power output value.
The performance adjustment factors are intended to represent the impact of system outages and down time for maintenance, due to curtailment, or for other reasons.
Best regards,
Paul.