グランド再生可能エネルギー国際会議論文集
Online ISSN : 2434-0871
最新号
選択された号の論文の72件中1~50を表示しています
  • Hironao Matsubara, Manabu Utagawa
    p. 1-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    This study presents investigation of the possibility of 100% Renewable Energy Scenario in Tokyo metropolitan area with green recovery process by 2050. In the Zero Emission Tokyo Strategy, the Tokyo Metropolitan Government aims to decarbonize 100% of its energy use by 2050 to achieve net zero CO2 emissions by using renewable energy as main energy sources and strengthen energy efficiency. To achieve this goal, a scenario for 100% renewable energy in Tokyo is examined, which corresponds to a sustainable economic recovery so called green recovery from the COVID-19, and the potential for energy conservation and the possibility of energy conversion through sector coupling are shown. The amount of renewable energy introduced in Tokyo will be increased as much as possible in consideration of its potential for introduction in the area, and mainly solar and wind power electricity will be procured from outside the area. Electrification for the use of renewable energy electricity will be promoted, but the use of renewable heat and hydrogen and green gas/fuel from surplus electricity in the region is also envisioned.
  • Toshihiro Inoue, Etsushi Kato, Atsushi Kurosawa
    p. 2-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    The Paris Agreement has prompted Japan to set a goal of zero net greenhouse gas (GHGs) emissions by 2050. This paper discussed the role of renewable energy toward carbon neutrality in Japan. In order to examine Japan's energy supply and demand in 2050, we used the TIMES-JAPAN optimization model, which is a bottom-up analysis of Japan's entire energy system. Employing this model, Japan’s long-term energy outlook is evaluated under the scenario on carbon regulation, variable renewable energy generation cost and negative emission technologies. In unconstrained CO2 emissions scenario, CO2 emissions in 2050 will be mitigated by approximately 50% from the level of emissions in 2015. In Net zero emission scenario which CO2 emissions sets zero in 2050, the share of renewable energy in primary energy will increase from 5% to 14% (UCE) and 38-51% (NZ) respectively in 2050.
  • Masaya Deguchi, Kentaro Shikata, Masayuki Hashimoto, Katsumi Kojiri
    p. 3-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    This paper overviews our power planning simulation and power operation simulation by minimizing social costs mainly based on merit order. Through the simulation, we have predicted the availability of power plants that our company will deliver and the amount they will be brought to power market in approximately 20 countries and regions. We will contribute to the achievement of its decarbonization goals by working with stakeholders through this method, focusing on technical requirements.
  • Suguri Taira, Yasushi Maruyama
    p. 4-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    The p urpose of this study is to descri be t hree str e a ms of ren ewa ble en ergy development in Tohoku , Japan after The Great East Japan E arthquake in 2011 with changin g o f Japanese energy p olicy to anal yze the inf l uence of the poli cies that affec ted this area Japanese renew able ener gy polic ies pro ceeded not only for the mitigation of cl ima te change but also for the transition from nuclea r power generation to distributed generation after the Fukus hima n uclear disaster . The To h oku area has enormous potential for sol a r energy a nd wind e nergy , that s why mega solar and onshore win d f a rm w as developed in this decade I t ha s developed rap idly for the first decade h owever , local people have complex feeling s about th e top down promoti on of the introduction of them and there are many controversial projec ts all over Japan. This paper tried to expla in renewab le energy changing in a rural areas in this decade to realize one of the backgrounds of confusing the current situation as least.
  • Kei Gomi, Hono Ishimoto, Kosei Takeyoshi, Richao Cong, Takuya Togawa, ...
    p. 5-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Municipalities in Japan have begun to decarbonize their energy systems by introducing significant amounts of renewable energy and building independent and decentralized energy systems. As a basis for the discussion, we projected the balance of renewable energy supply potential and electricity demand in each of the 59 municipalities in Fukushima Prefecture. We found that the total supply of electricity in the prefecture is more than twice as large as their demand, but that the supply is insufficient in some municipalities and that the supply-demand balance can be improved by aggregating the municipalities into seven regional blocs.
  • Nobuyuki Yamaguchi, Yusuke Manabe
    p. 6-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    A critical issue is how to secure the ability to adjust in the future due to the large-scale introduction of renewable energy. Supply-side and demand-side measures must be maximized to ensure flexibility in the future. In addition, it is necessary to make effective use of interconnection lines to ensure controllability. There are two ways to ensure flexibility using interconnection lines: strengthening interconnection lines and securing margins for interconnection lines in day-ahead planning for flexibility. Therefore, in this study, a simulation model that simulates unit commitment and economic dispatching control is used to quantitatively evaluate the policy for securing flexibility using interconnection lines. The analysis covers 8,760 hours per year in nine interconnected areas in Japan in the future.
  • João Gari da Silva Fonseca Júnior, Tomoya Takeuchi, Yumiko Iwafune, K ...
    p. 7-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Residual power demand is the demand left to be met by conventional power generators after considering the power generation of renewable energy systems. Knowing this quantity ahead of time can be useful in the planning and operation of power systems in markets with high penetration of variable renewable energy. In this study we investigate the potential to improve day-ahead forecasts of residual power demand one day ahead of time through three blending techniques tested over two years of data for the balancing area of Kyushu in Japan. The results show that averaging can improve the root mean square error normalized by peak value by 3% over the best individual forecasting method. The maximum improvement achievable with blending was also identified as reaching 20% over the same reference. Finally, an expert-based method yielded results slightly better than averaging, but further pathways for its improvement were discussed and identified.
  • Takayasu Kisaragi
    p. 8-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    As a countermeasure against increase in the dependence on renewable energy will further be inevitable in the future currently, renewable energy is classified into separate categories of solar power, wind power, biomass, and waterpower, etc., which have spread independently. This time, in this report, we attempted an integration of solar cell wing as wings for wind power generation for the first time in the world across a category barrier. Utilizing the wings of windmills as the ones for solar cell enables simultaneous capture of tow energies with different properties, and as a result, the integration and mutual complement of electric power can be expected in the day time, as well as at night, in this document, the overview of the prospects for practical use is reported through the operation check test of this unit.
  • Hiroki Yamamoto, Taiki Kure, Junji Kondoh, Daisuke Kodaira
    p. 9-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Machine learning methods have been developed for forecasting multi-point photovoltaic generation (PV). Multi-point forecasting is expected to improve forecast accuracy by learning Spatio-temporal cloud variability from the relationship of power generation among neighboring PVs. But multi-point forecastings may also complicate the calculation process and increase the number of unique models to forecast every PV. This study proposes a multi-Light Gradient Boosting Machine (LGBM) stacking model to predict PV generation 30 minutes ahead. The proposed multi-LGBM stacking can forecast multiple PV units by a single model, which doesn’t require multiple models for multiple PVs. Also, the proposed multi-LGBM stacking improved RMSE by about 1.29% compared to the existing LGBM, which trains each PV separately.
  • Kohei Agata, Yasutaka Kakoi, Noboru Katayama, Hiromi Kamei, Taiga Konu ...
    p. 10-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    In recent years, various failure detection methods for solar cells have been proposed. However, these methods have problems in detecting faults, and a general fault detection method has not yet been established. Therefore, we have introduced electrochemical impedance spectroscopy (EIS), which is often used for evaluation of electrochemical devices such as secondary batteries and fuel cells, to detect abnormalities in solar cells. In this study, we reproduced the mechanical deterioration state of the solar cell module, acquired the measurement data using EIS, and investigated the equivalent circuit that expresses this state. Nyquist and Bode diagrams of the measured results of the solar cell module and the values calculated by the proposed equivalent circuit agree with each other. This result indicates the applicability of the method for detecting defects in solar cells using EIS, and the method we proposed will contribute to the development of the field of maintenance and inspection of solar cells.
  • Jinesh Mohan, Tatsuya Wakeyama, Jeffrey S. Cross
    p. 11-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    With the rapid adoption of photovoltaic systems on the railways and their integration into the electricity grid, it has become a necessity to accurately forecast the photovoltaic output at their intended site of use for effective energy management to mitigate the instability of the grid caused by the intermittency of solar power. Inadequate data for the newly installed solar power plants is a severe bottleneck in forecasting and energy management. The research aims to overcome this by modelling a solar power forecast system using transfer learning from a pretrained Bayesian regression model capable of forecasting solar irradiance at the same location. The weather data from the data access viewer of NASA power website was used in the study. The predicted results were compared with the actual solar power output data from the datalogger of the Hyderabad, India Railway Station solar power plant. The resultant root-mean-square-error obtained is 96.50, and the mean absolute percentage error is 11.23%. The proposed method showed superior results compared to XGBoost and linear regression.
  • Yoshiko Koyama, Mitsuho Nakakura, Koji Matsubara, Yuya Akiyama, Tatsun ...
    p. 12-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    A steady state model was employed for the system analysis of thermochemical c arbon dioxide splitting. The model assumed the circulating flow of reactants between a reduction reactor and an oxidation reactor. A s olid solid heat exchange r was considered to recover waste h eat between react ive material after the reduction and that after oxi dation react ors . Ceria and Zr doped ceria were assumed as react ive material. The analysis showed that the efficiencies of both reactants exceeded 10%, Zr-doped ceria indicated a higher efficiency than simple ce ria, and the efficiency was improved by the heat exchanger.
  • Yasuko Miyakawa, Koki Kikuta, Nao Yamamoto, Shota Kawahata, Daisuke Ta ...
    p. 13-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    In Sapporo, Hokkaido, a snowy cold region that is handicapped by the external environment, we conducted an indoor environment survey and a questionnaire survey of office workers in an office building with ABW aiming to improve the comfort of the indoor environment. This report presents the results of a survey in the start-up phase of the operation. The study results showed that a comfortable indoor environment was realized by the thermal nesting system and hollow PC exteriors. As a result, the satisfaction level of the office workers with the indoor environment was also high. However, since this survey was conducted immediately after the start of the operation, we could not confirm the effects of Wellness office conversion and ABW introduction on intellectual productivity and Work Engagement.
  • Tomonori Minegishi, Yijing Zeng
    p. 14-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    In this paper, we introduce a sensing technology to control personal HVAC (Heating Ventilation and Air Conditioning) system in office buildings. We use thermal images taken by a high-resolution infrared camera installed in an office to estimate indoor position of occupants, air temperature around the occupants and the clothes they are wearing. For the indoor position estimation, we calculate the distance between camera and person using the person’s head size, and obtain two-dimensional coordinates of the occupants. The air temperature is roughly estimated from the temperature distribution around the occupants in thermal images. For the clothes estimation, we classify occupant’s clothes into long-sleeves and short-sleeves categories by applying transfer learning based on YOLOv4.
  • Iryna Borys Bohoshevych, Hiroatsu Fukuda
    p. 15-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    In this experimental study an alternative practical use has been given to a conventional Trombe wall setup by putting living plants into the ventilated cavity during the summer season. A low-maintenance Kratky hydroponic growing system consisting in putting 360 sweet basil plants in glass jars full of nutrient-filled water solution was used to cultivate the greens during the months of February to August of 2022, proving afterwards to be quite successful not only in practical terms but also from an economic standpoint. The initial setup and running costs per cycle are relatively low in comparison with the estimated revenues obtained by producing high priced edible greens. In this case study, the estimated revenues were above 3.85 million JPY over a 5-year long period. However, the most cost-efficient scenario was the one with a three-month seed to harvest period and four harvests per year, where over 6 million JPY can be obtained. This result can increase up to 10% more on a big-scale setting and with some setup improvements that have been found to be effective.
  • Erdenebaatar Enkh Uchral, Adyabat Amarbayar
    p. 16-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Good airtightness is essential to r ealize en ergy efficient building s . However, the issue of building airtightness has not been widespread yet in Mongolia. Thi s study intends to evaluate the airtightness performance of single family residential houses in Ulaanbaatar . The normalized test ISO 9 972 (Ther mal performance of buildings Determination of air permeability of buildings Fan pressurization method), known worldwide as the “Blower doo r test” is used to assess airtightness . This paper presents the results of a blower door test conducted i n eig ht houses The measured air change rate ( n 50 ) fluctuated from 0.2 1 to 12 6 ac/h at a 50Pa pressure difference betwe en the ind oor an d outdoor environment of the tested houses.
  • Jun Tanemoto, Tsenwei Lin, Kazuya Takahashi, Koji Sumida, Tetsuji Shir ...
    p. 17-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    In this paper, wind measurements of Dual Scanning Lidar (DSL) were validated against met mast measurements. Although the wind speed and the wind direction show good agreement with the met mast measurements, the turbulence intensity (TI) underestimates the cup anemometer measurement. It is also found that the degree of underestimation is related to the gate length of the lidars. Then, the correction method of TI by using a 3D random wind field was proposed. By using the proposed method, the spatial averaging effect caused by the gate length was corrected. Finally, the corrected TI shows good agreement with the cup anemometer measurement.
  • Masaki Shirai, Takahiro Ara, Maki Yamamoto, Toru Takeuchi
    p. 18-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Wind energy generation is increasing globally, and the associated environmental impacts must be considered. The risk of seabirds colliding with offshore wind turbines is influenced by their flight altitude. Flight altitude observations are usually made on boats, and estimates tend to be made during daylight hours in fine weather. As an alternative, global positioning system (GPS) tracking provides flight height information under a range of conditions. In this study, we tracked the foraging behavior of black-tailed gulls (Larus crassirostris) at sea using GPS data loggers. This species is abundant in the offshore waters of the Sea of Japan. Most GPS positions during flight mode (79%) were below or above the blade level (30–220 m), although 21% were in the blade-swept area. There was no clear difference in flight altitude at the blade level between the coastal (50 m in water depth) and offshore areas (50 m). This approach, and the associated data, provide information that may improve avian collision risk assessments for offshore wind farms.
  • Nanako Sasanuma, Akihiro Honda
    p. 19-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    In the previous paper [1], we have presented that the wind speed of the leeward wind turbine decreased in specific wind direction, and it could be affected by the wind turbine wake from the windward turbine using numerical simulation targeting two wind turbines in complex terrain. The aim of this study is to examine quantitatively the wind turbine wake effect based on the wind characteristics with topographical perspectives. We attempted the comparison of wind speed and generated power under two conditions, with effect of wind wake and without using wind data of actual onshore turbines. The two wind direction targets are the ones which can be leeward wind turbines for each other. This study shows that wind speed of the leeward wind turbine by about 25 35% decreased in the target wind directions when considering wind wake compared to the case without. It proved that power generation reduction consistent with wind speed reduction.
  • Toshiki Takahashi, Hinata Yamagishi, Hisashi Matsuda, Tasuku Tanaka, M ...
    p. 20-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    To study the airflow control effect of a plasma actuator (PA) on a simulated airfoil (equipped with a passive control wing on the upper edge of a photovoltaic cell), particle image velocim etry (PIV) measurements were carried out in the outdoors. A plasma electrode developed by Asahi Rubber Inc. is installed at the rear end of the passive control wing. As tracers for PIV measurement, we used soap bub bles generated from two types of supply de vices (a coaxial triple tube nozzle generator and a rotating cylindrical generator). The former can generate microbubbles with a diameter of about 0.9 mm, and the latter can generate many bubbles with a diameter of about 5 mm. Under the PA_OFF condition, t he wind speed measured by the propeller anemometer and the average wind speed measured by the PIV showed good agreement. It was confirmed that outdoor PIV measurement is possible by using soap bubbles as a tracer. We also confirmed the airflow control effe ct of the plasma actuator in the field.
  • Tasuku Tanaka, Hisashi Matsuda, Toshiki Takahashi, Takahiro Chiba, Nob ...
    p. 21-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Using a high durability designed plasma electrode (PA), the effect of snowfall flow control w as experimentally inv estigated for both a NACA 0015 blade model and a two dimensional backward facing step flow model. PIV measurements using a dry snowflake as a tracer showed that the snowfall flow could be controlled, and that a velocity increasing regi on was generated in t he separated shear layer when the PA was driven. Moreover, from the results of the snow accumulation test ( Re 1.4×10 4 ), it became clear for the first time that the amount of snow accumulated in the two dimensional, backward facing step flow could be reduce d when the PA was driven. The possibility of us age the high durability plasma electrode as a flow control device for a wind turbine in the snowy cold regions became clear.
  • Jin Matsunaga, Riku Usutani, Norito Sugawara, Hisashi Matsuda, Riho Hi ...
    p. 22-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    To study weather resistance of erosion sheets for wind turbine blade in snowy cold regions, a water spray adhesion tester, a rotating ice adhesion force tester, and a special erosion wind tunnel have been developing. In the water spray test, in a constant temperature laboratory cooled to -20 °C, a water sprayer (droplet diameter assuming raindrops = 270-450 μm) was driven and a test erosion sheet (150 mm × 150mm) is splayed with the spray water and ice-accreted. This ice-accreted sheet is rotated at ~3000 rpm in the rotation test apparatus having a diameter of 400 mm, and the ice-accretion force is determined from the centrifugal force when the ice is blown off. In the special erosion wind tunnel, sand and snowflakes collide with the test sheet at a speed higher than the blade tip relative velocity (50m/s~) of a 3.3MW wind turbine at average wind speed, and the state of the sheet surface is investigated. The outline of the development of each test equipment is reported.
  • Yuto Iwasaki, Tadashi Hosoe, Kazuki Ikeda, Tsuyoshi Nishitani, Aoi Tan ...
    p. 23-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    This report describes the results of an analysis of resonance phenomena investigated using a small wind turbine. The analysis was performed by generating resonance phenomena in a small wind turbine and performing a Fast Fourier Transform of its output. The characteristics of the resonance phenomena of the small wind turbine were also experimentally confirmed.
  • Junji Kondoh
    p. 24-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    In Japan, photovoltaic (PV) power has been considerably increasing, but is not able to contribute to winter heavy demand at night and on snowy days. In contrast, wind power is high in winter because of the monsoon,though its penetration has been relatively less as compared to PV power. In this study, winter capacity values of wind power in the eastern Japanese power systems (Tohoku and Tokyo) was evaluated. The findings revealed that the winter capacity values are sufficiently high in Tohoku but low in Tokyo.
  • Guo Wei Qian, Takeshi Ishihara
    p. 25-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    In this study, the mechanism of wake deflection induced by Coriolis force is firstly investigated through a momentum balance analysis. A new wake deflection model is then proposed to analytically predict the wake center trajectory at the hub height. The proposed wake deflection model is subsequently incorporated in a Gaussian based wake model. The velocity deficits in the wake predicted by the proposed model show good agreement with the numerical results obtained by high fidelity wind turbine wake simulation.
  • Shota Ishio, Takeshi Yoshioka, Toshiyuki Masatsuki, Fujio Uchiyama, Ta ...
    p. 26-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    In offshore wind power in Japan, the seismic response in the event of an extremely rare earthquake may become dominant in the design of support structures. To reduce the seismic response, it is desirable to consider the radiation damping of the soil as much as possible. In this study, we verify the simple method that can easily consider the radiation damping only in the second mode and higher for jacket foundations for offshore wind turbines. Specifically, we performed free damped vibration analysis for a second mode with and without radiation damping to find that the increment of the second mode damping due to the radiation damping effect and add to the second mode damping rate of the Rayleigh damping. As results of verification, we confirmed that almost the same damping effect was obtained by the models using the Gazetas formula with radiation damping, the thin layer element method and the simple method for jacket foundations. For monopile foundations, we should use the simple method because other methods overestimate the radiation damping for the first mode.
  • Huimin Lu, Yu Fujimoto, Yasuhiro Hayashi
    p. 27-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Short-term wind power forecasting is of vital importance for intraday power trading by assisting wind farm operators in making appropriate power selling plans and reducing the foreseen imbalances. However, the eventual imbalance penalties are affected not only by the discrepancy between the planned and actual values of wind generation but also by the market price. Specifically, a not-very-accurate forecast may be acceptable when the power price is low and the imbalance penalty price is correspondingly low, but a rather accurate forecast will be highly demanded otherwise. On the other hand, most of the related studies have focused mainly only on improving average prediction accuracy. In this viewpoint, a novel price-aware wind power forecasting method based on a long short-term memory neural network (LSTM-NN) with customized loss function for training is proposed, aiming to contribute to reducing the imbalance penalties that depend on the electricity market price.
  • Tong Zhou, Takeshi Ishihara
    p. 28-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    In this study, a formula for the maximum turbulence length scale 𝑙􀯠􀯔􀯫 is first proposed to reproduce the neutrally stratified atmospheric boundary layer over different terrain types considering the effects of Coriolis force. The effects of Coriolis force on turbulent flows over 3-D hills with different slopes and height ratios (hill height / atmospheric boundary layer height) are subsequently clarified in terms of flow patterns and turbulent statistics. The results show that the vertical distributions of mean velocity on the windward side of 3-D hills are slightly affected by the Coriolis force regardless of hill slopes and height ratios. However, it is found that the Coriolis force has a positive influence on the wake recovery of 3-D steep hills with large height ratios and its influence enhances as the hill slope and the height ratio increase. Moreover, the fractional speed-up ratio at the crest of 3-D hills is significantly increased as the hill slope and the height ratio increase.
  • Atsushi Yamaguchi, Akifumi Kyomasu, Takeshi Ishihara
    p. 29-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    In this study, the comparisons of the measured turbulence intensity by a Doppler lidar with the reference value in synthetic turbulent wind field are carried out. The standard deviation of the horizontal velocity components measured by the pulsed lidar shows larger value than the reference. Two correction methods are proposed to explain and improve these overestimations. One method is to use the correlation of the fluctuating horizontal and vertical velocity components and the variance of vertical velocity. The other is to use the variances of line of sight (LoS) and vertical velocities. Both methods improve the overestimation of the horizontal turbulences measured by the pulsed lidar.
  • Takahito Hamano, Takahiro Kiwata, Takuma Shima, Sotaro Takeuchi, Moha ...
    p. 30-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    The effects of the span length of the prism, and the gap between the splitter plate and the prism on the performance of the vibrational power generator by the flow induced vibration and the magnetostrictive material were investigated with the w ind tunnel experiment. The splitter plate was added to improve the performance of a vibrational power generator with a cantilevered rectangular prism and a side ratio D H of 0.4 (where D is the depth of the prism in the flow direction and H is the height o f the prism). The span length L of the rectangular prism was 200 mm and 300 mm. The high speed galloping vibration occurs in cases with a small gap. The vibration onset flow velocity and power generation are affected by the span length of the prism. As t he long span rectangular prism (i.e., L = 300mm) has a low characteristic frequency and starts to vibrate at a low wind velocity, this prism has a wide range of wind velocity for power generation as compared with the short span prism (i.e., L = 200 mm).
  • Tetsuya Wakui, Kouki Tanaka, Ryohei Yokoyama
    p. 31-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    The reduction effect of the dynamic loads of floating offshore wind turbine-generator systems by the feedforward-feedback control based on the previewed wind speed, which was developed in our previous study, is clarified through the theoretical analysis of the system response in the vicinity of an equilibrium operating point at the rated high-speed region. In the floating offshore wind turbine-generator system, the responses of the generator speed and platform pitch interfere; however, employing the feedforward control reduces their variations to the wind speed change in comparison with the gain-scheduled control of the generator speed. Furthermore, the response interference between the generator speed and the platform pitch is reduced, contributing to the improvement of their controllability.
  • Takuyuki Yoshioka
    p. 32-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    The Feed-in-Tariff Scheme for Renewable Energy (FIT) was launched in Japan in 2012 and the scheme has increased the energy utili ation of forest biomass. Although broad-leaved woody coppices have substantial potential, utilization of bulky branches has never been discussed in Japan, in spite of larger potential of branches of broad-leaved trees than those of coniferous trees. This paper outlines an experimental project for utilizing logging residues associated with the harvest of a broad-leaved forest for power generation in Japan.
  • Unggul Priyanto, Desy Septriana, Novio Valentino, Sekar Kumala Des ...
    p. 33-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Global warming and climate change have brought to the attention of many countries to use renewable fuels as energy sources. Developing renewable diesel fuel from vegetable oil is an alternative to replace die sel oil from fossil fuel. Renewable diesel production is performed by deoxygenating palm oil in a hydrogen free environment. Vegetable oil was deoxygenated with the help of a catalyst. Herein, the evaluation of catalytic deoxygenation of palm oil over Ni C aO catalyst supported by active carbon was investigated to compare the conversion of vegetable oil and the selectivity of products. The experiments were conducted at a temperature of 330 to 400 o C and first pressure of 20 bar in either N 2 gas or H 2 gas . Th e results obtained in this study showed that the deoxygenation reactions increased highly above the temperature of 350 0 C between 330 400℃. G reen diesel's highest yield and selectivity were obtained at 400℃ without external hydrogen gas
  • Mohd Fairus Mohd Yasin, Muhammad Thalhah Zainal, Natrah Kamaruzaman ...
    p. 34-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Flame synthesis provides a quick and affordable option for the prediction of carbon nanotubes (CNT), however laboratory test is often hampered by the difficulty of predicting the position of CNT growth within a non homogeneous flame environment. The simple chemistry (SC) technique used in the published multi-scale model requires further refinement to accurately predict the physio-chemical properties of the gas phase. Therefore, the primary goal of the current research is to improve upon the multi-scale model that previously combined computational fluid dynamics (CFD) with a growth rate (GR) model through the implementation of detail chemistry (DC). An inverse diffusion flame (IDF) powered by a blend of 30% methane and 5% ethylene is implemented in the present study. Using the flamelet method implemented in the CFD tool OpenFOAM, at horough validation of the CFD flame model of the IDF is performed for a baseline situation with 30% O2. As compared to the prediction made by the prior SC model, the accuracy of the predicted flame temperature and CNT growth region has increased by around 15% and 25%, respectively. A comparison of the DC model and the SC model reveals that, CNT growth and carbon density on catalyst particles are distributed at the fuel side of the flame when the DC model is implemented. This said observation indicates an improvement in the physical modelling of CNT growth since the SC model had previously predicted that CNT growth would occur in the oxidizer region which is not physical. Additionally, using the DC model eliminates the necessity for an artificial threshold for CNT growth truncation as predicted in the SC model, presenting another advancement in the physical modelling of the multi-scale model.
  • Tomoko Saiki, Akio Nishijima, Norio Ohto, Hideo Samura, Kinya Sakanish ...
    p. 35-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    This study aims to clarify conditions and environments of current biomass plants that support sustainable operation and to propose policies toward the construction of the Carbon-Neutral Society in 2050. This study focused on several successfully operating biomass power plants that differ in location and raw material supply. We visited the biomass power plants and biorefineries and interviewed their managers. Domestic small-scale power plants with domestic raw material supply have been established through local initiatives and have contributed to job creation. Integrated biorefineries, bio-clusters, represent a sustainable form of biomass refinery. We propose strategies for biomass power plants, including improvement in power generation efficiency through capacity expansion and technological progress. We propose to promote integrated biorefineries, bio-clusters, that accommodate biomass power plants. We propose short and mid-term to long term policies, and international cooperation.
  • Obie Farobie, Latifa Aisya Anis, Edy Hartulistiyoso, Novi Syaftika ...
    p. 36-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Hydrothermal carbonization is an environmentally benign approach to producing hydrochar from wet biomass owing to no need for a pre-drying process. This study aims to examine the effect of temperature and time on hydrochar characteristics from the hydrothermal carbonization of Ulva lactuca. The hydrothermal carbonization was performed using a batch reactor. The effect of temperature was performed at 180, 200, and 220 °C. Meanwhile, the holding times varied between 30, 60, and 90 min. The results showed that the hydrothermal process could significantly affect carbon and oxygen contents in macroalgae, but it was not the case for hydrogen, nitrogen, and sulfur content. It might be because the mild temperature condition of the hydrothermal process could not enhance the formation of the hydrogen, nitrogen, and nitrogen gas. The hydrothermal carbonization can increase the energy contents of U. lactuca by over 42%. The highest HHV of 21.07 MJ/kg was achieved at 220 °C which is comparable to typical low-ranked coals.
  • Apip Amrullah, Indah Permata Sari, Obie Farobie, Yukihiko Matsumura
    p. 37-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    This research study examined the pyrolysis of green macroalgae (Ulva lactuca) for the first time. In addition, the reaction kinetics of the solid degradation that took place during the pyrolysis process of Ulva lactuca were examined and figured out. Several experiments were carried out in a batch reactor to study the impact of the different pyrolysis temperatures (400-600 oC). Within 50 min at a temperature of 500 °C, the most bio-oil was produced (24.1%). Using the Arrhenius equation, the pre-exponential factor and activation energy fo the solid degradation was calculated for the first time as 3.51x1010s-1 and 126.46 kJmol-1, respectively. This was the first time these values had been determined.
  • Hiroyuki Aso, Ki yotaka F uji
    p. 38-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    While the global focus is on decarbonization, Japan is struggling to introduce renewable energy.Japan's small size and the fact that 70% of its land area is covered by mountains and forests limit the potential for lar ge scale solar power generation and wind power generation in particular. On the other hand, the trees in those forests are aging, and furthermore, erosion by moso bamboo, a non native sp ecies, is causing landslides. Therefore, we are aiming to develop a sm all biomass boiler, assuming the mixed burning of bamboo and fast growing trees in addition to woody fuel. In this case, the moisture content of the woody fuel is a very important factor in the combustion of the boiler. It is known that the higher the wate r conte nt of wood fuel, the lower its lower calorific value and we focused on a method to efficiently recover the water content of woody fuel and conducted experiments.
  • Shinya Sato , Kimihiko Sugiura
    p. 39-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Although a popularization of Polymer Electrolyte Fuel Cell (PEFC) is expected as clean energy, high manufacturing costs have hindered its widespread use, and reducing the amount of platinum catalyst is a top priority for further spread. Generally, although the catalyst layer (CL) of MEAs is manufactured by the doctor blade method, this method has problems such as a poor dispersion of Pt catalyst in the CL and a difficulty in controlling the film thickness. Therefore, our laboratory has proposed the application of inkjet coating printing to the manufacturing process of CL to solve these problems. Because the IJP method can form the optimum catalyst layer structure by dotting ink droplets of about 50μm using different catalyst inks with different ionomer to platinum catalyst ratios (I/C ratio), it can reduce the amount of Pt. If dots are drawn with different catalyst ink compositions on the same electrode surface and in the catalyst layer thickness direction, a three-dimensional catalyst layer structure can be formed. This paper examined the effect of two-dimensional catalyst layers with I/C ratio distribution within the same electrode on cell performance. As a result, it was found that the I/C ratio distribution contributes to the improvement of cell performance.
  • Patxi Garcia Novo, Yusaku Kyozuka, Daisaku Sakaguchi
    p. 40-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    With the first tidal stream energy arrays already operational, the issue of the impact of one array on other nearby farms has arisen. It is expected that, when located in one single channel, two arrays upstream/downstream will cause a reduction in the power production of both farms, while two farms side-by-side will benefit from each other. However, this impact has not been quantified yet. This paper analyzes the interactions between three proposed farms in Naru Strait (Nagasaki Prefecture, Japan). Two farms are located side-by-side, while the third one is at approximately 3 km downstream/upstream. Several case studies are evaluated, differing in installed capacity per array or farm layout. Results show the influence of location, layout, and installed capacity on the variations in power production caused by nearby farms, with percentual values ranging between -0.90% and +4.76%. This paper demonstrate the need of a regional strategic planning for tidal stream energy exploitation if resource optimization is prioritized.
  • Shota Tsukamoto, Takehiko Asai, Kenji Yoshimizu, Yudai Nemoto, Urara ...
    p. 41-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    In recent years, ocean energy such as winds and waves has been attracting attention as promising renewable energy sources. Especially, offshore wind turbines (OWTs) show great potential, and various kinds of OWTs have been proposed so far. Among these, floating OWTs are considered more suitable for Japan due to the deep waters in the nearshore area. However, floating type is vulnerable to wind- and wave-induced vibration compared to bottom-fixed OWTs. On the other hand, a novel wave energy converter (WEC) with an inerter mechanism was proposed. This study is inspired by this WEC and proposes floating OWTs with externally installed buoys employing inerters for vibration suppression and wave energy conversion. A simple analytical model including the effects of additional mass, radiation damping, and wave excitation force on the floating body is developed for the heave direction. Then, appropriate design parameters are examined, and active control scheme is also applied to improve the performance further. The results obtained from WEC-Sim (Wave Energy Converter SIMulator) show that the proposed device works to control the floating OWT and generate wave energy effectively.
  • Koji Tanaka, Atsuhiro Iwamoto, Tomoaki Utsunomiya
    p. 42-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Offshore wind technical potential has been shown to be approximately four times higher in deeper water areas suitable for floating offshore wind turbines (FOWTs) than in shallower water areas suitable for bottomfixed offshore wind turbine. Particularly in Asia and North America, where the technological potential for floating offshore wind turbines is high, the installation of FOWTs is highly desired in these areas to further reduce greenhouse gas emissions. Because these areas are subject to typhoons and hurricanes, FOWT installations require accurate simulations of both power production and extreme environmental conditions. Therefore, in this paper, we compare the simulated and measured values in the power production using Adams with SparDyn, which has already shown good agreement with the measured values in the typhoon environment and validate the simulation tool.
  • Hui Chi Phua, M.S. Chiong, N.I. Mahyon, M.H. Padzillah, A Takada, ...
    p. 43-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Ocean Thermal Energy Conversion (OTEC) is a potential green renewable energy source, especially for tropical coastal areas. The system utilizes the temperature difference between surface and deep seawater to convert into electrical energy. The system is referred to as Hybrid-OTEC (H-OTEC) when coupled with seawater desalination. This paper investigated the emission intensity of a 1 MW H-OTEC proposed in Malaysia via Life Cycle Assessment. The inventory data for the working cycle and structure is obtained by scaling up the 3 kW H-OTEC pilot plant in Malaysia. Two upscaling methods were investigated, namely the conventional 0.6 rule and the newly proposed “Thermodynamics scaling method”. The 1 MW H-OTEC is shown to associate with 71.5 g CO2-eq/kWh of emission intensity, 85% lower than the small-scale pilot plant and becomes comparable to mainstream renewable energies. In addition, the Thermodynamics scaling method is more reliable for H-OTEC upscaling, otherwise would result in about a 25% underestimation in emission intensity prediction. Further upscaling of H-OTEC will bring its emission intensity to a more competitive level with the other large-scale mainstream renewable energies, making it a more favourable choice for Malaysia’s future renewable energy mix.
  • Gyuyoung YOON, Hideharu NIWA, Naoki TAKAHASHI, Kiho YOSHIOKA, Osamu K ...
    p. 44-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Based on five years of operation of a ground source heat pump system, the long-term operational performance and optimum operating conditions of the system were investigated. It was confirmed that the system operated stably during the study period and that there was no significant performance degradation due to long-term operation. Lastly, as part of the study of optimal operating conditions, a heat source water distribution would maximize the performance of the heat exchangers investigated, and it is effective to search for the optimal operation plan based on actual operation data, as in this case, in order to guarantee the long-term operating performance of this system.
  • Takeshi. Ishihara, Akira Tomigashi, Youhei Uchida
    p. 45-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Estimation of Apparent thermal conductivity by depth is suitable for evaluating the thermophysical properties of different geological formations. Thermal conductivity profiling (TCP) using heating cable and borehole was conducted total of 53 sites in Fukushima, Saga, and Okinawa Prefecture and data of apparent thermal conductivities were categorized by geology. The median values of apparent thermal conductivity for each sediment are generally consistent with literature values (“effective thermal conductivity”), respectively. Differences in the apparent thermal conductivities of granite and mudstone were observed between Fukushima Prefecture and other prefectures, respectively, suggesting that it is important to consider the regional characteristics of physical properties when evaluating the apparent thermal conductivity of a rock.
  • Nobukazu Soma, Munetake Sasaki, Miu Nishikata, Keiichi Sakaguchi, Hiro ...
    p. 46-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    This paper describes a resource evaluation method by evaluating the amount of geoscientific information such as hydrothermal alteration zone, where the potential amount of geothermal power generation is connected to actual power generation to reduce the misfit with a practical exploration result. We created simple estimation formula based on the Multiple Regression model of the capacity of the power plant using both hydrothermal alteration zones and hot springs. A relatively good estimation was obtained by using 18 power plants, and an example map of the potential amount of power generation in the Sengan area is shown. The proposed method indicates agreement with existing potential maps and advantages such as spatial distribution so further improvement of the performance and usefulness of this approach is worth considering.
  • Junzo Kasahara, Yoko Hasada, Hitoshi Mikada, Hiroshi Ohnuma, Yoshihiro ...
    p. 47-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    We have conducted geophysical studies using the optical fiber sensing method in Japan's six hot geothermal wells to develop a new geophysical method to explore geothermal subsurface structures. The temperature profiles were obtained from six surveys using the optical five-distributed temperature sensing (DTS) method. The hottest temperature was 288°C at 2,000 m depth. The obtained temperature profiles differ from one to another, suggesting differences in the local geological circumstances. We obtained seismic records from active sources with distributed acoustic sensing (DAS) method. Using seismic rerecords, we obtained the subsurface velocity structure of the survey region. The DAS records of all sites showed numerous seismic reflections to ca. 4 km depth, which could be caused by fractures filled with fluid. Our study proved to be very useful for the geophysical characterization of geothermal fields. The reflective zones imaged by reflected arrivals can be used for the subsequent investigation of geothermal development.
  • Isoji Miyagi
    p. 48-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    I estimated the abundance of geothermal resources (geothermal fluid) for Kakkonda and Aso Nakadake using the petrological method. In the Kakkonda area, the estimated geothermal fluid is a flux of 0.5 to 16 M tons/year, with a temperature of 600 to 700°C. In addition, during the formation of the Kakkonda granite via crystallization of basaltic magma, an extremely large amount of, equivalent to about 50 vol.% liquid water relative to that of the Kakkonda hot rock body, geothermal fluid was potentially released. This geothermal fluid may have played an important role in the generation of the hydrothermal system of Kakkonda. The estimated geothermal fluid annually released from Nakadake, Aso, is 9 M tons with a temperature of 1050°C.
  • Mincheol Cho, Hirohisa Aki
    p. 49-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    Electric vehicles (EVs) have penetrated the power network of the apartment (APT) buildings. With the development of power electronic devices, bidirectional power transmission between the EV battery and the power network has been potentiated. EV batteries can choose the states of charging and discharging as distributed resources in response to the power demand from the residential space, that is vehicle-to-home (V2H) system. There is a high possibility that EV batteries tend to be charged in the parking lot of the residential space using various types of chargers such as an on-board type. This paper proposes a power management system that cooperates with the V2H system managing the allocation of sharing charger in the APT building. To assess the proposed system, three different V2H systems were developed and compared.
  • Masahiro Taniguchi, Akira Kojima
    p. 50-
    発行日: 2022年
    公開日: 2023/02/01
    会議録・要旨集 フリー
    In recent years, renewable energies have been introduced into the power grids in large quantities due to the global warming and resource depletion. However, since power generation by renewable energy depends on the surrounding environment, maintaining a balance between supply and demand for electricity is an important issue. On the other hand, the development of solar radiation forecasting and short-period wind power forecasting technologies is providing the predictive information for the control of power systems. In this paper, we design an 𝐻2 preview control law for the load frequency control systems, which considers the prediction error of the information. The strength and limitation of the preview LFC is investigated from the viewpoints of the prediction error and the resulting frequency variation.
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