This paper presents analysis of the characteristic of persons who have installed residential photovoltaic generation, and factors that led to install. Especially, we focused on the difference between the persons who had the installation intention but not installed yet and the persons who had already installed photovoltaic generation. The questionnaire surveys were conducted to compare both persons.
As a result of the analysis, the following were clarified.（1）The persons who had installed photovoltaic generation were shifting from an ardent demographic to a general one. This reason depends on measures for spread of photovoltaic generation having changed in the age.（2）The installation intention was related to the recognition of benefit of photovoltaic generation and the installation action was related to the recognition of cost burden of photovoltaic generation. The information on the Internet and books were extracted as factors that stimulated the recognition of cost burden. Government subsidies, information on the Internet, and communication among familiar persons were extracted as promotion factors that led to the installation action of photovoltaic generation.

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To build up the hydrogen energy society, hydrogen compression process is needed to be highly efficient. To construct highly efficient hydrogen compression process, chemically hydrogen compression process by redox reaction of iron oxides is focused on in this study. This process can be driven only by factory waste heat and it has higher thermal efficiency than mechanical hydrogen compression. In this process, reaction rate of deoxidization is investigated with changing reaction temperature and existence of steam. From our results, low temperature reaction rate of iron deoxidization is largely inhibited by the existence of steam. However, its reaction rate is restored by rapid removal of steam. It is clear that low temperature activation of deoxidization is achieved by rapid removal of steam.

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With actions to reduce greenhouse gas emissions slow, an increasing number of scientists are calling for research into climate geoengineering, in light of heightened recognition of the risks of dangerous climate change. Previous studies have shown that the probability of the atmospheric temperature rise exceeding 2 degrees Celsius is fairly large even for scenarios with enormous mitigation efforts. Using a well-known integrated assessment model, the Dynamic Integrated model of Climate Economy, we show that solar radiation management (SRM) such as stratospheric aerosol injection has a potential to drastically reduce such probability of exceeding 2 degrees Celsius in an ideal case. We also consider the case in which SRM itself might introduce negative side effects. The result shows that the optimal amount of stratospheric aerosol injection is non-zero and can improve overall output even if the side effects of geoengineering are assumed to be much larger than CO₂-driven damage. Our analysis demonstrates large economic benefits of geoengineering, although its research and deployment require serious considerations of ethical, social, and environmental aspects of this technology.

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The use of renewable energy was considered as likely to be effective in achieving an environmentally friendly campus in the medium and the long term. Kyoto University commenced an experimental project involving the use of regional renewable energy in early 2011. The main aim of this study was to clarify the energy savings and CO₂ reduction achieved in this project by the use of regional renewable energy . Solar heat and the energy from burning wood pellets produced by forest thinning were used as renewable energies in this project. These energies were used as a partial energy source for an air conditioning system in a building in the Uji campus, which is one of the campuses in Kyoto University. From the results, the fossil-derived energy savings and CO₂ reduction were estimated to be 1,729 GJ/yr and 119 t-CO₂/yr, respectively. This implied that a reduction of 53.7% of fossil-derived energy consumption and 55.7% of CO₂ emission could be achieved by modifying the existing air conditioning system. The uncertainty analysis indicated that the results of the estimation ranged widely according to the change in the running load of the air-conditioning equipment. The practical and operational aspect of this project needs to be taken into account through actual monitoring, and further evaluations of other environmental impacts or the cost-benefit performance are needed.

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This paper describes the outline of integrated energy economic model and calculated result concerning Japan’s energy demand and supply outlook and carbon dioxide emissions to 2050. The energy model developed in this paper is integrated one which consistently combines econometric model endogenously generating various socio-economic factors and bottom-up type technology model, MARKAL, identifying cost-minimizing optimal mix of various energy technologies. Employing this model, Japan’s long-term energy outlook is evaluated under the scenario on both carbon regulation and nuclear power generation. In no carbon regulation scenario, CO₂ emission in 2050 will be mitigated by approximately 40% from the level of emissions in 2005, if nuclear power plants will be constructed according to governmental electricity supply plan. Sluggish growth in nuclear power plant, however, would alternatively increase carbon-intensive coal-fired power plant which eventually boosts CO₂ emissions. In carbon regulation scenario, imposing emissions cap of 60% reduction by 2050 from the emissions in 2005, renewable energy are expected to expand its portion in power generation mix, and the role of natural gas-fired power plant equipped with CCS would further expand if the deployment of nuclear power plant becomes stagnated.

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This paper develops long-term projections on energy supply and demand up to 2035 with particular focus on Middle East countries, based on the analyses of world trends that are already evident or expected to emerge in the future, and describes the methodology of forecast and major projected results of the energy demand and supply. In Reference Scenario, the Middle East countries’ primary energy consumption will grow at a rate of 2.2% per annum in the period up to 2035, from 592 Mtoe in 2008 to 1075 Mtoe in 2035. More than 50% of the expected increase in primary energy consumption will be accounted for by increases in Saudi Arabia and Iran. Vigorous growth of electricity demand in Middle East is expected to 2035 on the back of economic growth and population increase. Therefore, future profile of power generation mix is considered as influential factor in energy outlook. In Technologically Advanced Scenario, which assumes that all Middle East countries take technological advanced measures and that accelerated R&D encourage global deployment of advanced technologies, primary energy consumption will decrease by 13% compared with the Reference Scenario in 2035.

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This paper presents economic impact of deploying “money-saving” low carbon technologies in the household sector, such as switching from incandescent light bulbs to LED bulbs or installing rooftop solar panels. In the traditional economic assessment of transition to the low carbon economy, the existence of such money-saving technologies is ignored. We suggest different micro effect of such technologies than cost increasing technologies. We firstly evaluated micro impact of money-saving technologies to the households, and secondly combined with macro structural change into the applied general equilibrium model of Japanese economy (AGE2005 model). The result showed that deploying money-saving low carbon technologies will increase economic welfare of household sector, without GDP reduction, because money-saving technologies will increase consumption level, and instead of decreased electricity demand, other consumption goods and services will increase especially machinery and related materials. In the case with feed-in tariffs for the electricity from rooftop solar panels, economic welfare decrease but very slightly than in the case with carbon tax.

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Cost-effective measures to reduce greenhouse gasses in the transport sector are a critical issue for policy makers and industries. Although numerous model-based studies have been conducted to find possible solutions, none of these models pay much attention to the important points as follows: (1) appropriate constraints on EV range and (2) the variety of the vehicle mix at the near optimal solutions. To address the issue, we developed a small scale, multi objective linear programming model, called the vehicle mix optimization model, determining the vehicle mix to minimize the total cost or total CO₂ emissions in the given period. We introduced multiple classes of the lifetime mileage into the model. The results are summarized as follows: (1) the optimal vehicle mix solutions vary widely between the models with/without constraints on EV range, but (2) in another settings of parameters the solutions are the same between the two models, and this implies the importance of analysis of model behavior, and (3) there exists wide variety of the vehicle mix solutions at the near optimal solutions.

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