Ecotype hydraulic turbines can be utilized small and distributed water resources with little civil engineering works and without environmental burdens. In Japan, network of agricultural waterway extends 400 thousands kilometers, this abundance of waterpower has a high expectations for electric power generation to supply to agricultural facilities. This promotes local production for local consumption of electricity. Four types of turbine, Savonius turbine, waterfall turbine, jet turbine and undershot turbine, were investigated and demonstrated in some fields. We have been also investigated the standalone smart grid system which can harness a several types of ecotype turbines. It can control the amount of generation power and supplying electricity. In this manuscript, we summarize our results of the investigation of ecotype hydraulic turbines.
The Ocean Thermal Energy Conversion (OTEC) power plant is a system for generating electric power using the temperature difference between the surface and the deep water of the ocean. It is an environment-friendly source of energy. Unlike most of the renewable energy resources which are weather dependents, OTEC system provides a stable source of electricity along the year because the surface and the deep water temperatures are constant. In addition, the seawater used for electricity generation can be further used in many fields, such as desalination of seawater, agriculture, and Lithium recovery. To realize the OTEC system, various studies have been conducted for long time; one of the fields of these studies is on the use of non-azeotropic mixtures as working fluids in order to make use of the increase of the system's exergy. One of the advantages of the ammonia/water mixture is the big difference between its boiling point and its dew point. As the use of ammonia/water mixture as working fluids was in its initial stage, there has been great concern regarding the stability of the cycle because the difference between of the boiling point and the dew point of ammonia/water mixture is larger than that of CFCs. In this paper, it is introduced on the research trend and activity of Ocean Thermal Energy Conversion, especially, the challenge on ammonia/water mixture including multiphase flow research and the OTEC Road map toward 2030 by Japanese NEDO (New Energy and Industrial Technology Development Organization).
Japan Agency for Marine-Earth Science and Technology (JAMSTEC) is operating a scientific drilling vessel CHIKYU which is an ultra-deep water drillship. The CHIKYU is operated under an international science program, the Integrated Ocean Drilling Program (IODP), and her primary mission is to drill the deep sea floor and to explore the deep earth for science research. She is sometimes engaged in the exploration of natural resources. In this paper, outline of the CHIKYU and drilling techniques for deep ocean floor are described.
This paper summarizes the results of author's studies on solar energy resource utilization. One is the development of a micro solar power generation which was combined with micro wind power generation at urban area. The other is the solar thermal utilization by an absorption heat pump for air conditioning. Daily fluctuations of energy supply in Osaka city both by electricity and by town gas were presented precisely in order to understand the energy consumption of urban area. Then, field test results about a micro hybrid power generation system were presented at urban coastal area where there is few wind power resource. Lastly, the performance of a solar-assisted absorption chiller heater of 352 kW refrigeration capacity has been introduced through a long series of proof examination of 17 months.
A numerical forecasting model of the on-site solar spectral irradiation for photovoltaic generation is developed by coupling a meteorological model and an atmospheric irradiance model. The intensity of the solar irradiance, which mainly changes due to clouds shading and scattering, is one of the dominant parameters of the photovoltaic power generation. The coupled model developed in this study consists of three parts: First, the mesoscale meteorological model is applied to evaluate the atmospheric condition including clouds existance. Next, the optical thickness of clouds is evaluated by considering the amount of clouds and diameter distribution of their particles. Finally, the direct and scattering solar irradiance at the ground is evaluated by taking into account not only the effect of the clouds but also the atmospheric gasses, e.g. Ozone, Oxygen and Carbon Oxide, in each wave length. The direct and scattering solar spectral irradiance evaluated with this coupled model is applied to compute the electric generation of any kind of photovoltaic systems. The coupled model's forecasting can be applied to control the unstable photovoltaic output from the ordinal power generators.
Particle image velocimetry and ultrasound velocity profiling have around 25 years in history from their first appearance on literature. The early type of their instruments measures flows only at very slow speed in simple spatial structure. The rapid advances in computing tip above silicon cycle escalated them onto the stage of wide applications from fundamental study in fluid mechanics to major experimental tool for designing, managing, and evaluating of thermo-fluid phenomena. Extension to multiphase flow in the last decade is making their big news both in science and engineering researches. This article reports on the current topics and technical problems in multiphase flow toward next generation.