With the increasing consumption of traditional fossil energy, progress on the renewable energy attracts more and more attentions. Solar cells that convert the solar energy into electric energy, has been one of most important technology in the renewable energy domain. In this paper, an instrument which can continuously measure the electricity generation of several solar panels is developed and tested. Under different weather conditions, performance of several mainstream solar cells that available in the market was compared. The generated electricity by different solar panels was normalized to the area and nominal power. Based on the experimental results, performance and characteristic of different solar cells at different outdoor conditions are provided and analyzed.