The parameters on the Parasitics page describe parasitic electrical loads and other losses in the power tower system.

Page numbers relevant to this section from the Wagner (2008) and Kistler B (1986) references are:

The parasitic loss variables are factors that Solar Advisor uses to calculate the estimated total parasitic loss and hourly parasitic losses, which are described in more detail below.

Solar Advisor calculates two types parasitic loss values. The first is an estimate of the total parasitic losses used to calculate the power block design thermal input, and the second are the hourly values calculated during simulation of the system's performance.

Note. Parasitic losses from components that do not exist in the system should be set to zero.

Parasitic Energy Consumption

Startup Energy of a Single Heliostat (kWe-hr)

The electric energy in kilowatt-hours required to move each heliostat into position. Applies during hours when the heliostat is starting up.

Tracking Power for a Single Heliostat (kWe)

The electric power in kilowatts required by the tracking mechanism of each heliostat in the field during hours of operation.

Receiver HTF Pump Efficiency

The electro-mechanical efficiency of the receiver heat transfer fluid pump.

Storage Pump Power (MWe/MWt)

The ratio of the electric power in kilowatts required by the storage pumps to the thermal power passing through the storage system.

Balance of Plant Power (MWe/MWe)

Losses as a fraction of the power block nameplate capacity that apply in hours when the power block operates.

Cooling Tower Parasitic Power (MWe/MWe)

The cooling tower parasitic losses as a fraction of power block nameplate capacity are electrical losses that occur when the power block operates at part or full load.

Piping Loss Coefficient (Wt/m)

Thermal loss per meter of piping. Includes piping throughout the system.

Total Piping Length (m)

Length of piping throughout the system: From the receiver to power block, power block to process heat, etc. The piping loss varies with output produced by turbine.

The estimated total parasitic losses value used to calculate the power block design thermal input displayed on the Power Cycle page is based on the estimated total parasitic loss factor, which depends following variables and values:

The estimated total parasitic loss factor total_par in MWe of losses per MWe of power block nameplate capacity is given by:

total_par = stor_pump_par × stor_hours × 0.20 + 0.03 + bop_par + cool_par

Where,

The total estimated parasitic losses in MWe is then:

total parasitic loss estimate = total_par × Nameplate Capacity

Where Nameplate Capacity is the power cycle electric capacity from the Power Cycle page.

Solar Advisor reports the hourly parasitic losses described in the tables below in the hourly results.

Table 27. Parasitic loss variable names used in hourly performance data.

The parasitic loss variables are calculated from the parasitic loss factors on the Parasitics page and variables from the hourly simulation.

Table 28. Equations used to calculate parasitic loss quantities in the hourly performance data.

The total parasitic load Par_total is the sum of the following parasitic losses: