Sunlight
From FOnline: 2238 Wiki
Sunlight, in the broad sense, is the total frequency spectrum of electromagnetic radiation given off by the Sun. Sunlight powers the Solar Scorcher, rare pistol in 2238.
Note: You can simulate adding a little sunlight to your game screen by pressing the + (plus) key on your numeric keypad, or with the = (equals) key. Darken it with one of the - (minus) keys.