Solar Array
Solar Arrays are attached to the outer hull of the ship and the power they generate is based directly upon the size of the array, the direction it is pointing (towards or away from the nearest sun) and the distance to the nearest sun.
They do not provide any power when in deep space (too far from sunlight) but can be a useful supplement to power for damaged ships within solar systems.
The power generated from a solar array is not massive, but if spread over enough area can provide a useful boost. A typical 1 meters square panel will generate 100 KiloWatts of energy at about Earths distance from the sun. Therefore a 100 meter by 40 meter panel would generate 400 MegaWatts of power. Unlike Fusion Reactors and Warp Cores, using solar arrays does not generate a tell tale magnetic field so it is effective for staying hidden from enemy ships.
Upgrading the solar arrays can improve the efficiency (up to a maximum of 200 KiloWatts per square meter).
They are very fragile and will easily be destroyed during combat. Their resilience can be increased with research.