Abstract: Gravity powered electrical energy generators, particularly for producing lighting is disclosed. The apparatus has a support frame (1, 30) in which a series of gears and a gear-driven generator (20) are mounted. The power to drive the most upstream gear (2) is provided by a weight suspended from a point to one side of the axis of rotation of gear (2). The drive gear of the furthest downstream gear has no teeth so that the final contact between the drive gear and the shaft of the generator (20) is frictional. The gear ratio of the final downstream gear is at least 25. When used for lighting, the apparatus may include one or more high brightness LEDs (40) mounted on the housing (30). By suitable choice of gear ratios, the device may produce thirty minutes of illumination while allowing a 10 kilogram weight to fall through a distance of 1.8 meters.