Professor Jo, Chul Hee has finished his Mater degree at Stevens Institute of Technology, USA in 1985 and Ph.D in Ocean Engineering at Texas A&M University in 1991. After working for Intec Engineering, Houston USA and Hyundai Heavy Industries, Korea from 1992 to 1997, he has joined to Inha University in Korea. His main research area is tidal current energy and he has been involved in many government advisory bodies and committees in ocean energy policy, development planning and research since 1998. Being the first author in ocean energy text book written in Korea, he has published more than 200 journal and conference papers with more than 80 patents registered and pending in tidal current energy field. Prof. Jo has been conducted numerous government and industry projects developing tidal current generation system. He is currently the director of the Ocean Energy and Environmental Research Center and the vice president for KSNRE (Korean Society for New and Renewable Energy) and the Executive committee member for AWTEC (Asian Wave and Tidal Energy Conference). focusing.
A focus on renewable energy has been increased as the global warming problem rises. The tidal current power, one of ocean energy resources is acknowledged to have a great potential due to its high energy density with continuous and predictable advantages. Tidal energy technologies can be applied effectively in areas having regular current distribution such as in the ocean with tides and also in rivers with current. To extract energy in a large scale farm, a large number of devices are to be installed for feasible commercial operation. Studies have been conducted throughout the world to find the interaction effect for multi arrayed tidal current devices. The total power production rate of a farm is affected by the turbine arrangement and it interaction. To maximize the power production in the tidal farm equipped with horizontal axis tidal turbines, it is important to understand the wake behavior and its range of influence to downstream. The related papers have been introduced by many researchers with CFD and experimental approaches together with limited experiments. However, the results are quite different from each other. These are due to various boundary and initial conditions with various design factors applied. Also the experiment results vary from each other. In this research, published papers relating to interference effects for multi array of tidal turbines are compared and evaluated. From the analysis, the reasonable velocity recovery rate with axial gaps considering the wake effect downstream is suggested.
Tianhao Li is currently a student of Experimental High School Attached to Beijing Normal University. He is concerning about environmental protection and energy development. He uses his spare time to investigate and survey wind power and photovoltaic corporation; understanding how macroeconomic environment, technology and market factors affect corporations.
Utilizing renewable energy is an important approach to conserve resources, reduce pollutant emission and improve air quality. Wind energy and solar energy are important components of renewable energy. In this presentation, the author put forth his opinion on the development of wind and solar energy in China. The government supports the development of renewable energy, having enacted related laws, launched a series of policies and worked out long-term planning; the scale of wind power and photovoltaic power is in a rapid growth; wind power and photovoltaic industry play an important role in reducing the consumption of coal, restraining pollutant discharging, such as carbon dioxide and at the same time contribute to comprehensive resource utilization. Power enterprises' main cost of investment is electric equipments, which is in a downward trend in recent years. Power enterprises sometimes cannot take full advantage of capacity and result in wind and solar curtailment. Government offers subsidy of on-grid power tariff, but on-grid power tariff is declining, lowering the earnings of investors. The market competitions of photovoltaic and wind power industry are intense as well. The unit cost of renewable energy industry, especially photovoltaic and wind power is reducing and technical progress increases the efficiency of electricity generation at the same time. Although subsidy of on-grid power tariff is declining and market competition is fierce, wind farm and photovoltaic enterprises are still making profit. Renewable energy only accounts for a very small percentage of whole energy consumption but it has great potential in China, able to reduce pollutant emission and realize comprehensive utilization of resources. National policies have great influences on industry development, thus the government should guide and support the development of renewable energy.