negative and zero values

Hello,

The power tower system generates no electricity at night after energy is depleted from storage. During those hours, the cycle gross output is zero, and the net output is negative to represent the electricity required to meet parasitic loads.

On the Parasitics page, the "Fraction of rated gross power consumed at all times" accounts for the negative values you see. That represents the electricity requirement of the facility and is not dependent on the system's electrical output.

Also, be aware of any losses specified on the Power Cycle page under "Availability and Curtailment." The default power tower case assumes a 4% loss, which is reflected in the system's electrical output.

Best regards,
Paul.