Power Source Components

Internal Power | Processed Power | Solar Array

Power source components model the method that a spacecraft uses to generate power. These components are implemented in engine models.

Power Source	Description
Internal Power	Power generated internally.
Processed Power	Power available from a power processing unit (PPU).
Solar Array Power	Power generated by a solar array.

Internal Power Source

The properties that define an internal power source are described in the following table.

Internal Power Source Properties

Attribute	Description
GeneratedPower	Power generated by the spacecraft from internal sources.
PercentDegradationPerYear	Degradation factor is (1 - x%/yr)^{timeSinceRefEpoch}
ReferenceEpoch	Date and time used as a reference epoch for degradation.

Processed Power Source

The properties that define a processed power source are described in the following table.

Processed Power Source Properties

Attribute	Description
Load	Power diverted from the power source and unavailable to the PPU.
Efficiency	Efficiency of the PPU unit.
InputPowerSource	Source of power available to the PPU.

Solar Array Power Source

The Solar Array Power Source calculates one parameter, Power:

Where F_th is the Thermal Model Factor, D is the degradation factor (measured from the reference epoch), CE% is CellEfficiencyPct, AE% is ArrayEfficiencyPct, and ISL is the angle InclinationToSunLine. Flux is defined as:

where F_au is the solar flux at 1 au (from the central body file), and R_s is the apparent distance to the sun.

The properties that define a solar array power source are described in the following table.

Solar Array Power Source Properties

Attribute	Description
Area	Solar array panel area.
Concentration	Solar array concentration factor.
CellEfficiencyPct	Cell efficiency in producing output power from incident sunlight.
ArrayEfficiencyPct	Array efficiency in producing output power from a collection of cells.
PercentDegradationPerYear	The degradation factor is (1 - x)ⁿ, where n is the time since epoch in years, and x is the percent degradation per year.
ReferenceEpoch	Date and time used as a reference epoch for degradation.
InclinationToSunLine	Angle from the panel normal vector to the apparent sun line.
ThermalModel.ApproximationFormula	Read-only string that reflects the formula given above.

Thermal Model Attributes

The Thermal factor is calculated as a function of the distance (in AU) to the Sun:

In this equation, r is the magnitude of the radius vector in AU. You can define the coefficients, ThermalModel.C₀ through ThermalModel.C₄.