Above the atmosphere the solar constant is fixed: Gsc ≈ 1361 W/m². A geostationary solar-power satellite (SPS) sees this flux essentially continuously — its panels track the Sun and it passes through Earth's shadow (eclipse) only briefly near the equinoxes, for a small fraction of the year.
Orbital flux: F_orbit = G_sc · cos(θ_sun) (θ_sun ≈ 0 with active tracking)
Ground flux: F_ground = G_sc · e^(−k·AM) · sin(elevation) · (1 − cloud_loss)
Air mass: AM ≈ 1 / sin(elevation) (Kasten–Young approx., clipped near horizon)
A terrestrial array loses energy to three things an orbital array does not: (1) the day/night cycle removes ~half the day entirely, (2) low sun elevation at dawn/dusk forces sunlight through many more atmospheric path-lengths (air mass), scattering and absorbing it, and (3) clouds and haze scatter/absorb further. The simulator integrates both fluxes over a simulated day to show the resulting energy-per-area gap.
To deliver the harvested power to users, an SPS converts it to a microwave beam (~2.45 or 5.8 GHz, chosen because the atmosphere is nearly transparent at those frequencies) and beams it down to a large ground receiving antenna (a rectenna), which rectifies the microwaves back to DC/AC power. This sidesteps the need to physically transport energy from orbit.
- Time scale — speeds up the orbit so a full day/night and eclipse cycle can be observed quickly.
- Sun-tracking — toggles whether the orbital panel actively re-orients to face the Sun (realistic for an SPS) versus staying fixed, which lets the cos(θ) loss show up.
- Latitude / cloud cover — control how much air mass and scattering the ground array must fight through.
- Beam power — animates the microwave downlink from satellite to rectenna.
Real-world relevance: this is the core argument behind proposed orbital solar programs (JAXA, ESA SOLARIS, Caltech SSPP) — near-continuous, weather-independent collection can offset the cost and complexity of launching and beaming power down.