Solar cells are the most effective approach for sustainable energy to meet the world's increasing needs in energy. However, their large-scale applications have been limited by low cost performance, supply of raw materials, complex preparation processes and the possible pollutions produced during processing. Here we introduce a novel fiber solar cell housed in a simple and low-cost parabolic-shape reflector, which can effectively capture diffuse light from all directions. The maximum efficiency of the fiber based dye-sensitized solar cells alone reached 7.02%. Furthermore, the maximum power output was enhanced by a factor of two and five, respectively, when the fiber was in conjunction with a diffuse reflector or a micro-light concentrating groove.