An optimization method has proposed for the renewal planning of energy systems installed into buildings, and the effectiveness is verified through a numeric calculation. This enables us to derive the optimal renewal planning logically without the judgment by intuition and the experience. In the mathematical optimization formulation, the annual total cost of the system is minimized in consideration of system's operational strategy corresponding to seasonal and hourly energy demands requirement. Using this optimization method, to give consideration to not only economic but also energy saving, the optimal renewal planning for buildings was clarified, which decide renewal year and selection and capacity of equipment.

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In order to operate energy supply systems optimally from the viewpoint of energy and cost savings, it is necessary to predict the energy demand accurately. In this paper the parameters of a neural network model are identified with a global quasi-optimal method, and the method of predicting the energy demand was examined. In addition to the past energy demand, as an input to a model, weather conditions, such as an actual measurement and predicted values of air temperature, relative humidity, the sensible temperature, and the discomfort index, were taken into consideration. The prediction method was applied to the cooling demand in a building used for a benchmark test of a variety of prediction methods, and its validity and effectiveness are clarified.

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Simulation models of three types of air conditioning system combined with ventilation have been developed. The compared systems are as follows: (A) Duct type ventilation and air conditioner, (B) Duct type ventilation and air conditioner which inhale indoor air mixed with supply air (outdoor air), (C) Total heat exchange ventilation system and air conditioner. We calculated total energy consumption and indoor humidity in order to evaluate the effects of difference of ventilating system under various combinations of outdoor air temperature and humidity. As a result, we clarified that the annual energy consumption of system (B) decreases 3.4% compared with that of system (A), because the air conditioner operates efficiently by the indoor air mixed with the supply air. And we also clarified that the annual energy consumption of system (C) decreases 9.1% compared with that of system (A), because the air conditioning load decreases by the total heat exchanger of the ventilator.

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Convergent calculation is possible using Microsoft Excel. It has advanced program functions. Then I have developed a new program technique that is called 'Objectinized Cells Method'. System simulation of the air conditioning unit is enabled by this new method. Furthermore, I developed non-steady thermal load calculation technique within the spread sheet. Non-steady heat conduction equation is solved by the finite volume method. The air conditioner and thermal load calculations are analyzed at the same time. The temperature and humidity of the chamber, and the air conditioner's blast temperature is obtained by result of calculation. Calculation is executed every 2 minutes. These principal parts are calculated within the spread sheet, and macro are only used rarely.

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The double diffusive phenomena in solar pond were numerically studied at the Prandtl number Pr=6, the Lewis number Le=100, the Rayleigh number Ra=10^6 or 10^7 and the buoyancy ratio N=0 to 20 for a two-layer system which consists of a pure water (upper layer) and an aqueous solution (lower layer) with the heating from the entire bottom. The heat from the source on the bottom accumulates owing to thermal plumes in the lower layer efficiently in the case of both large buoyancy ratio and high Rayleigh number.

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Recently, the mobility which is more comfortable than a thing of an article for handicapped people to obtain social barrier-free as well as necessity of mobility machinery for elderly society is demanded. We are aimed for development of an electric wheelchair as next generation mobility machinery which is equipped with a fuel cell system as a new energy source and which realized power-saving and lightweight. We set the target value by questionary survey to wheelchair users and strength analysis on software, and the body adopted lightweight material.

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Recently, development and the spread of small, lightweight, environmentally-friendly and high-efficiency single-seat fuel cell electric vehicle are expected. Then, in order to realize this concept, we designed and manufactured for ULFCV (Ultra Lightweight Fuel Cell Electric Concept Vehicle) applying the development technology of competition vehicle. In this paper, to realize more practicability, we considered the power system and the body of the ULFCV. Then we selected best available fuel cell and capacitor and battery. On the other hand, we improved mass production type ULFCV to use in a car sharing system. We tried to reflect users' opinions to the body design. Next, we simulated the ULFCV strength by FEM analysis for the purpose of confirming its safety.

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In this paper, we aim at the construction of the environmental-friendly use system of automobiles whose large environmental load is pointed out as significant problems. Our base concept is "Up-grading" product, which realizes long life and environmental-friendly using by the up-grading of main components and also improvement of users consciousness. First, we performed an Eco-drive examination to realize its effect. As a result, we can get some effects by Eco-drive without average speed changing. Therefore, we propose the supporting device to promote the practicing Eco-drive. It is the device which the users can learn about Eco-drive after their driving with animation and running data. We aim to bring up eco-users and to improve the consciousness of drivers.

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The purpose of this study is to analyze the effect of cooling by the water atomization in the Shinkansen train base. The temperature of the train base which vehicle is cleaned and is inspected exceeds 40℃ in summer. We established the water atomization in a part of the Shinkansen train base and experimented that changing the quantity of water to grasp the characteristic of the system. The temperature descent by latent heat of water mist was 5℃〜6℃ in favorable term.

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Renewable energies such as wind power or photovoltaic energy are environmentally focused but the fluctuation of output power of renewable energies may cause excess variation of voltage or frequency of the grid. Increase of the amount of renewable energies would violate the quality of the grid. The micro grid in which dispersed energies compensate the variation from the renewable energies can expand the installation limit of the renewable energies by maintaining the quality of the interconnected grid. In this paper how the distributed generation and secondary batteries absorb the power variation from the wind generation and the loads is discussed. In order to control the output power, gas turbines and gas engines must run at partial load operation, which results in lower efficiency. Considering the efficiency of the micro grid, installed capacity of wind power generation system, and frequency stability for islanded operation, performs the evaluation of the micro grid.

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The energy saving in urban area is one of the most important issues recently. As the redevelopment of the medium scale area is more frequent than that of the large scale area, it is meaningful to investigate the energy saving potential of regional energy supply systems for the medium scale area. In the study, the simulation of the regional energy supply systems installed in the medium scale area was performed. Four systems, namely, the individual system, the district heating and cooling system, the energy center, and the micro-grid, were evaluated by comparison. The energy saving potential was calculated against the individual system. It was found that the micro-grid could achieve the energy saving by 16%, which was the largest.

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Recently, in many cities, thermal air pollution has arisen from superfluous progress of the increase in artificial waste heat and covering, and loss of natural space. Consequently, in the city, compared with the suburbs, temperature becomes high and the heat island phenomenon has appeared. As the measures, it is very important to control the radiation. Therefore, we notice membrane materials which have small solar absorptance. In this study, we selected three membrane materials of polytetra fluorine ethylene (white, gray, yellow green), and these solar absorptances and infrared emissivities were measured. These solar absorptances were 0.19, 0.53, 0.70 and infrared emissivities were about 0.9. We applied the measured values to the math calculation and evaluate surface temperature for construction and sensible heat flux to the atmosphere. Consequently, the surface temperature is lower and the sensible heat flux decreases. So, it is expected that membrane materials mitigate the heat island phenomenon.

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This paper describes fundamental numerical simulation results of the radiative heat transfer among urban structures, non-gray gases, and a human body in an urban street canyon. One-dimensional and three-dimensional numerical simulations were conducted by using Monte Carlo Method and Elsasser's narrow band model in order to verify the characteristic of the effect of non-gray gases (H_2O, CO_2, and CO) on radiative heat flux to the human body. The simulation results show that the effect of non-gray gases increase in proportion to the logarithmic distance between urban structures and human body. These results indicate that the non-gray gases play an important role in the radiative heat transfer to the human body and thermal comfort in the urban street canyon in summer months.

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The diffusion of NO_x around Ikegami-Shinmachi crossroads was analyzed by a CFD model. This is a suspended four-lane express road with a six-lane ground-level road under the expressway and another four-lane ground-level road intersecting the two roads. The boundary conditions were given with the results from the mesoscale meteorological model. The calculations indicated high concentrations in the morning and low ones in the afternoon but did not indicate high concentrations in the evening. There still remained not negledgeble difference between the calculated results and observation.

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The objective of this study is to estimate introduction of solar water heaters. The installation potential is related to the cost of the device and the reduction of hot water supply currently produced by fuel. First of all, the maximum annual energy cost savings corresponding to roof orientation were estimated to find optimum angle of the installation. The adoption possibility of the solar water heaters were determined by the calculated annual energy cost savings taking into account user preference which was evaluated from questionnaire survey. Then, the roof orientation was investigated using GIS (geographic information system) because the performance of solar water hearts depend on the orientation. Finally, the possible energy savings were obtained for Tokyo region. The results showed that 35,000 houses would have possibility to install solar water heater in Tokyo. The CO_2 emissions would be reduced by 8500 tons by the introduction of solar water heaters. If the cost of the device could go down to half price, the potential would increase up to 94,000 houses, which would give 3times as much energy savings as the regular price gives.

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Ocean thermal energy conversion (OTEC) is a power generation system that utilizes small temperature differences between the surface and deep sea water. This paper describes the simulation results of the thermal efficiency of an OTEC plant that utilizes not only ocean thermal energy but also solar thermal energy as a heat source. This power generation system is termed SOTEC (solar and ocean thermal energy conversion). Simulation results of a 100-kWe SOTEC plant, in which the solar collector is installed in two configurations, are obtained and compared with those of an ordinary OTEC plant. The simulation result shows that the proposed SOTEC plant can enhance the annual mean thermal efficiency up to 1.5 times higher than that of the ordinary OTEC plant.

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Aluminum roll-bond panels bonded with crystal silicon solar modules were used as the evaporator of a heat pump. The rated capacity of the compressor was 250W and the total area of the panels was 1.91m^2. The coefficient of performance around noon was 5.2 when the ambient and water temperatures were 10℃ and 30℃, respectively. The electric power generated was about 170W when the solar radiation intensity was 800W/m^2. The electric conversion efficiency of the modules increased 20 to 30% by the cooling effect of evaporation. The analytical results of COP using the plate factor of 0.75 agreed well with the experimental results.

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During the last decade, photovoltaic generators were well-integrated into buildings along with the development of photovoltaic technologies. There are, however, some obstacles to the spread of building integrated photovoltaics (BIPV), especially to the use for the attachment to vertical walls. In Japan, the solar altitude angles in summer is high, and therefore, the decrease of the power generation from PVs on vertical walls is significant in summer. In the study, we develop a novel concentration power generator which is integrated into double facades of buildings. The system consists of a nonimaging Fresnel lens type solar concentrator for the outer facade, and solar cells attached on the surface of the inner wall. The Fresnel lens was designed to accept the transition of the position of the sun during the daytime without tracking. The paper describes the design strategies and the results of simulation by the ray-tracing method.

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A thermochemical system combined metal/metal hydride hydrogen producing process with the AMTEC is discussed in this paper. The thermochemical system consists of dehydrogenation section, AMTEC device, and electrolysis cell. At the high temperature side, the dehydrogenation section and the AMTEC device share direct connected alkali metal working fluid. Thermal input from a heat source is used for dehydrogenation of metal hydride, and then heat and alkali metal are transferred into the AMTEC device, which provides electrical output for the electrolysis cell in the low temperature side. The operational parameters of the direct connected hydrogen producing process are analyzed. The relationship between generative electrical potential of the AMTEC device, temperature conditions and pressure drops is discussed in detail.

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This paper presents the study of a development and assessment for bio ethanol mixing fuel boiler. Recently, bio ethanol is expected as one of the measures for global warming. However, we try to use it only for an alternative gasoline source, and we do not nearly consider other ways of using it. Then, we focus to boiler whose fuel is heavy oil or kerosene, and develop bio ethanol mixing fuel and bio ethanol mixing boiler. The boiler has the same performance of combustibility, and reduces almost 19% CO_2 and 27% ELP (Environmental Load Point) in life cycle compared with the boiler whose fuel is heavy oil or kerosene.

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Since fossil fuels such as petroleum, coal, and natural gas are limited resources, renewable energy such as solar, wind, and biomass will be needed as substitute fuels. We manufactured the practical Stirling engine using biomass fuel in 2005. And a new type of engine system that uses woody biomass fuel such as sawdust, firewood and woody pellet was proposed in this report. A burner using the woody biomass fuel heats the air in the expansion room to about 650℃ and a water cooled system cools the air in the compression room to about 60℃. In this condition, the new engine provided 3kW of electricity. And the heat from this engine powered electricity generating system can be recovered and used in a number of ways for space and domestic water heating.

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Microbial fuel cells (MFCs) are expected to become direct energy conversion devices driven with organic matter in wastewater from industrial plants, food factories and agricultural processes. Recently, many researchers in Europe and the United States have been trying to develop the novel electricity generation systems based on MFCs. In most of previous work, the major target is to find out more effective pairs of microbes and electron mediators. From the veiwpoint of safety for handling, baker's yeast, i.e. Saccharomyces cerevisiae, is selected to use in the present electricity generation experiments. The prototype of a MFC consists of two compartments, i.e. the anode side and the cathode side containers, divided by a proton exchange membrane (Nafion 112). The baker's yeasts with O.1M phosphate buffer solution (pH 7.0), glucose as substrate and a drop of methylene blue dilute solution as electron mediator were put in the anode side container. In the cathode side, 0.2M potassium ferricyanide was stocked with O.1M phosphate buffer solution (pH 7.0). Carbon paper, of which area was 9cm^2, was employed for the electrodes, and a variable resistor was used as an electrical load of the MFC. Throughout the experiments, the open circuit voltage (OCV), the current-voltage (I-V) and the current-power (I-P) characteristics were obtained in some cases with different operating conditions. The OCV of the present MFC prototype was found in the range between 0.5V and 0.6V. In addition, it is clarified that the power output increases together with solution temperature in the range between 11.4℃ and 33.5℃ and the power density at 33.5℃ reaches 35μW/cm^2. The initial yeast content and the initial concentration of glucose also affect the electricity generation performance.

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As well as heating in modern greenhouse, carbon dioxide (CO_2) enrichment of internal atmosphere by fossil fuel-fired CO_2 generator is commonly held for high yield and high quality products. This paper introduces the possibility of CO_2 emission reduction for protected horticulture by temporary CO_2-storage technology using the lithium silicate, which can be used repeatedly as a solid CO_2 sorbent by temperature swing operation. The trial model of the CO_2 enrichment system includes the manufacture of some parts such as the blower, dampers and pipes but not the CO_2 storage unit, in which there are some containers packed with pellet of lithium silicate sorbent and electric heater plates. CO_2 absorption and supply mode can be automatically selected on each approptiate time cycle using a 24-hour timer on the control panel. CO_2 emission is expected to be reduced by more than 30% with this system compared to the conventional system. This environment-friendly and high-yield production will be demonstrated in the greenhouse of the agricultural experiment station.

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