Miyako Nakayama obtained her business bachelor degree in Hosei University in Japan in March 2015. Since 2015 fall, he has been majoring in Mechanical Engineering to seek a second bachelor in the University of Idaho. In summer 2017, as a sophomore student, he had completed comprehensive research on Wind Energy based on extensive literature reviews, which covers both technological and business perspectives and has been on the process to publish her research paper.
Due to the environmental concerns from the use of traditional fuels such as coals, the US Environmental Protection Agency (EPA) is currently requiring power plants to meet air pollution regulations, which could cause power shortages and even blackouts in the state of Texas. The purpose of this study is to evaluate the feasibility of using onshore and offshore wind turbines (WTs) in Texas based on levelized Cost of Energy (LCOE) analysis. This study is based on a scenario that multiple wind turbines can be installed in available onshore lands and offshore seas of the state of Texas. A commercial WT is selected for both onshore and offshore situations and the corresponding LCOEs were analyzed. Secondly, the maximum number of WTs which can be installed in the available areas was determined based on a spatial distance criterion. Lastly, the maximum annual energy output and the maximum average power output for both situations in Texas was estimated. Although offshore WTs are considered to be more promising technology which can produce more energy and power these days, our results showed that the selection of the two wind turbine types may vary using different indices and number of turbines. 1. In terms of LCOE, onshore WT is more economical due to the lower LCOE. 2. In terms of Capacity Factor, offshore WT is more power-efficient due to the higher capacity factor. 3. In terms of Annual/Average energy and power output, A. For a single WT, an offshore WT produces more power and energy than onshore WT. B. For WT farm, onshore WTs produce more power due to more number of turbines that can be installed in available windy land.
Hiroshi Nishiyama completed his Ph.D. at Nagaoka University of Technology, Japan in 2005. In 1998–2013, he was an assistant professor at the Analysis and Instrumentation Center at Nagaoka University of Technology. He is currently a principal project researcher in the R&D Laboratory of Artificial Photosynthetic Chemical Process (ARPChem) at The University of Tokyo. His research focuses on the development of high-performance photoanode electrodes and high-performance PEC systems.
Photocatalysis or photoelectrochemistry are attractive developing fields of engineering for building free-running sunlight-driven water splitting to generate H2 and O2. We are surveying solar-spectrum-responding semiconductive materials as the candidates for the visible light absorbers in the H2+O2 harvesting devices. We have been fabricating and testing water photo-splitting devices composed of a pair of photocathode (p-type, for H2) and photoanode (n-type, for O2) both decorated with catalysts for evolving those gases. As for photocathode, we developed H2 evolving flat layered sheets based on chalcopyrite Cu(In, Ga)Se2 (CIGS, the cutoff wavelength of absorption ~ 1100 nm) and its doped versions with Zn, S, etc. The photocurrent obtained by the solar simulator (AM 1.5G) can afford more than 10% of solar hydrogen conversion efficiency. The photoanode material is the remaining problem to solve. BiVO4 (~540 nm), paired with CIGS, realized a stable operation for the stoichiometric faradaic evolution of H2 and O2, however, the maximum solar-to-H2 efficiency has been below 4 %. Obviously, we need n-type light absorbers with longer cutoff wavelength. We are also developing transition metal nitrides and oxynitrides for the sunlight absorbers. Ta3N5 (~600 nm) has been the most intensively investigated, as particles embedded on metal layers (particle transferred sheets) and flat layered thin films, both of which can serve as photoanodes. Foreign materials can be assembled as the background layer or capping layer for the Ta3N5 layer to improve the electronic properties and robustness as an electrode immersed in the electrolytic solution. We will discuss the best performance for Ta3N5 and oxynitrides as O2-evolving photoelectrodes energized by solar irradiation.