Attraction, Challenge and Current Status of Marine Current Energy

Reducing greenhouse gas emissions becomes a top priority in the world with the emergence of global warming and environmental problems. Various renewable energies appear during the last decades. Ocean captures and stores huge amounts of energy, which could satisfy five times of world energy demand. Due to technology limitations and economic considerations, marine current energy appears the most attractive choice compared with the other ocean energy form. Although the existing expertise and technology in offshore wind energy conversion system can be partially transferred to marine current energy conversion system due to the similar structure, there are still many technological challenges to overcome. Meanwhile, the system operates under the water will inevitably have some negative or positive impacts on the surrounding environment. In this paper, it shows the interest and the principle of the marine current energy, and also discusses the advantages and disadvantages. The environmental impacts around the devices, the technological challenges, and the essential support structures are presented as well. The state-of-the-art horizontal axis turbines and their relative technologies and the latest projects are described finally. This review paper gives the useful information about the attraction and challenge of the marine current energy, and the newest development of the technologies and projects.