Abstract
This paper illustrates general factors influencing costs and expenses, and prospects of tidal power plants including barrages, lagoons, and streams. After the gathering data from existing papers and analysis, it is concluded that tidal systems are not economically viable mainly due to prohibitive capital costs, so it is believed that governments will contribute the most to the development of tidal energy. Furthermore, having low capacity factors of tidal systems indicates that even those with high installed capacity do not generate electricity as much as other power plants with low installed capacity. In the end, I reached a conclusion that, although with the advantage of predictivity, later researchers need to come out with new designs of tidal system, which can employ its original advantages and at the same time decrease the capital cost significantly