The amount of CO₂ emission from the electricity sector has been increasing during the past three decades in Japan．Analysis of Input-Output table (I-O table) is one of the most useful methods to estimate energy consumption and environmental burdens on industrial activities． We have developed 1970-2000 time series input-output tables based on the sector criteria of 1995 I-O table，and then reconstructed the sectional energy and environmental database by using 1973-2000 energy balance tables． This paper aims to estimate direct and indirect energy consumption and CO₂ emission of the Japanese electricity sector by the TSIO tables in order to understand environmental burdens effected by the past structural change of industry． Energy analysis ratio and CO₂ emissions per unit of yen are estimated on the different power sectors such as hydro，nuclear and fossil fuels power generation during the period of 1973-2000．

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The long-term stabilization target of greenhouse gases is discussed with the consideration of the post-Kyoto treaty. However, it is very difficult to decide the target level because of large uncertainties of global warming and its impacts, and inevitable value judgments. For example, EU proposes that the increase in global mean temperature should be below 2 ºC from pre-industrial level. We conducted integrated assessments of global warming damages and mitigation and adaptation measures for different stabilization levels, and investigated which level Japanese experts consider to be preferable from the provided quantitative results of impacts alleviation and emission reduction costs which were scientifically obtained. Based on the evaluations of and the comparison with the Stern Review that intends to be a recent comprehensive assessment of global warming, this paper discussed how we should deal with the issue of long-term target and whether they are appropriate. Our highly consistent analysis indicates that around 550 ppmv stabilization is justified better than the EU-proposed target or the levels recommended by the Stern Review, and will contribute towards leading discussions on the post-Kyoto treaty.

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A new model which describes the process of diffusion of renewable energy industries is presented in this paper. Production cost i.e. price of new industry decreases with growth of its cumulative production by the learning effect. On the other hand, some customers prefer renewable energies despite their higher prices compared to conventional energies because of their environmental premium. Then we tried to express this customer behavior by the theories of contingent valuation method (CVM), and to derive endogenous growth of production in renewable energy industries, by combining the CVM theory with the learning theory. Renewable energies are usually promoted by subsidy and the fact that total budget of subsidy is restricted makes the analysis more complicated, because not all the customers can receive subsidy. Taking this factor into account, we identified the demand function of the residential photovoltaic as an example of renewable energies and predicted the growth of production and price changes.

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The purpose of this research is to estimate the consumers' preference of energy-saving and environment-conscious automobiles in China by employing a conjoint analysis.
In December 2006, a questionnaire survey for choice-based conjoint analysis was conducted for 130 households in Shanghai. Using the data of a questionnaire, a choice logit regression model was used to analyze survey data and estimate Marginal Willingness to Pay (MWTP).
As a result, the estimated MWTP for "fuel cost " is 7570 yuan per car. The MWTP for "Drive System " is 6820 yuan per car. The "fuel cost " and the "Drive System " are the factors relevant to energy-saving and environment-conscious. However the MWTP for "fuel cost " and "Drive System " are smaller than the difference of the selling price of the energy-saving and environment-conscious car and the other ordinary car. This results show that the environmental market for cars in China is not a mature one.

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This paper describes a kinetic analysis of devolatilization rates of woody biomass by a model based upon distributed activation energy model and calculation results of proceeding of devolatilization of woody biomass in a simple carbonizer. Weight loss during pyrolysis of the woody biomass was measured by a TG in three different heating rates. The data of weight loss with time were processed according to the method proposed by Miura to determine provability density functions of activation energy distribution, f(E), and corresponding frequency factors k₀. Original method proposed by Miura cannot be adapted directly for the analysis of devolatilization of biomass because of decreasing in the activation energy with proceeding of the devolatilization. However, approximate activation energy distribution functions and frequency factors, with which devolatilization reaction could be well simulated, were obtained for woody biomass by a modification of original method proposed by Miura. For woody biomass, the provability density functions for the activation energy distribution were so different from those of coals that f(E) could not be expressed by a simple distribution function such as Gaussian distribution. This may correspond to the pyrolysis behaviors of the major components of biomass such as cellulose, hemi-cellulose and lignin. Predicted and measured amounts of remaining volatile matters in the chars were in good agreement. Thus, an optimum operation condition of a simple carbonizer was determined by a model using the parameters obtained. Calculations show a combination of highest heating temperature of 700K, rapid heating, short holding time, and rapid cooling is the best operating condition for a simple carbonizer in the view point of operability and energy saving.

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The adsorption heat pump system is considered to be one of the leading technologies for utilizing low temperature thermal energy, because it can generate cold heat energy at around 283 K for air conditioning without any mechanical power by utilizing low temperature heat as the regeneration heat source of an adsorbent. Many theoretical and experimental studies have already been conducted with the objective of enhancing the cold-heat output of the adsorption heat pump system. However, there are still some problems in the practical use of the adsorption heat pump system. The most serious problem is that the small cold heat output per unit volume of the adsorption heat pump, and its reasons were the bad vapor diffusion and heat transfer in the adsorption layer. For increasing the cold heat output, we have considered ammonia / SAC combination adsorption heat pump from the viewpoint of the promoting the vapor diffusion. We modeled in the heat transmission and the vapor diffusion of the adsorption layer, and estimated them. The result indicated that ammonia heat pump has the very good vapor diffusion, and the only heat transmission is rate-controlling step in the ammonia adsorption heat pump.

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This paper presents a method to visualize the performance of residential energy conversion apparatuses for heat/electricity supply, which is useful for the comparison among various apparatuses. Considering the difference in the energy usability or exergy, the energy conversion performance is visualized by the two-dimensional vector diagram consisting of electricity flow and heat/fuel flow. The energy conversion performance is shown as the differential vector between input (fuel and electricity consumption) and output (heat and electricity demand) vectors. Because the output is set at the origin of the diagram, the comparison of performance between various apparatuses can be visualized in one diagram. The proposed diagram is demonstrated to show the operating performance of various apparatuses by using the actual data of hot-water and electricity demand observed in 8 households.

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We propose a diffusion analysis model that integrates logistic-curve diffusion model (Bass model) and consumer preference model based on conjoint analysis. We built a diffusion model for clean energy vehicles (CEV) based on the proposing framework. The major CEV in Japan today is Hybrid Electric Vehicles (HV). 258 thousand HV have been sold in Japan by 2006FY. As the results of our analysis, in the base case, 700 thousand CEV were estimated to diffuse in 2010 and it has the effect of reducing CO₂ emissions by 660 thousand ton-CO₂. The model estimated that 4.0 million CEV diffuse in 2020, 16 million CEV diffuse in 2030, and 37 million CEV diffuse in 2050. We carried out two scenario analyses. In the scenario in which the subsidy of 250 thousand yen (2 thousand US$) is granted to CEV until 2020, the diffusion increases by 18% in 2020 and 11% in 2030, respectively, compared with the base case. In the scenario in which the gasoline price rises incrementally up to 4 times until 2050, the diffusion increases by 7% and 11%, respectively.

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