2. Why ?
1. Terrestial Energy shortage/queues
2. Solar power efficiency
Space offers near-continuous solar power at roughly 1,361 W/m² at the top of atmosphere — 5x to 10x more usable flux than the best terrestrial sites — along with free radiative cooling and zero water consumption.
Philip Johnston: Most orbits aren’t suitable because satellites spend roughly half their time behind Earth’s shadow, which would require batteries, similar to the challenge of harnessing solar power on Earth.
We use a specific orbit called a dawn–dusk sun-synchronous orbit. In this approach, the satellite essentially follows the Earth’s terminator line and remains in continuous sunlight. That eliminates the need for large-scale energy storage and creates a highly stable power environment, arguably more stable than on Earth, since you don’t have weather, humidity, or other environmental variability.
So if a sun-synchronous orbit is configured properly, the satellite would theoretically never enter Earth's shadow, and batteries wouldn't be necessary to compensate for darkness during half the orbit—which is exactly your point.
The skeptics' argument about needing batteries for the "no sunlight half" of the orbit doesn't actually apply to sun-synchronous orbits in the way it would for a standard circular orbit around Earth's equator. A sun-synchronous orbit solves that specific problem.